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T-98A Transmissions VS T-90

Transmission Oops!

Model 18 T-Case

Spicer 18 Rebuild

Hot Spicer 18

T-90 Rebuild

Shifters Rattle

T-90 Cluster Gear Bearings

Grinding Gears In A T-90

T-90 Output Shaft Nut

Transfer Case Brake

Spicer 18 Xfer Overhaul

Advanced Adapter To T-90 Question

Model - 18 = 26 Or 29 Tooth?

Vernomatic 5000

Remote T18 Transfer Case

Grinding 2nd And 3rd Gears

T90 Stuff Quick Fix Kit

Transfer Case Question

Transfer Case Markings

Safety Wire On Spicer 18


Lower Gears

T86AA Conversion

4-Speed Solution

T-90 Rebuilding Guide Page

Warn OD Manual (Viewable)

Warn OD Manual (Printable)

T-case Oil Level




James Roney wrote: If you can find a T98, that already has the correct adapter in it, it is a vast improvement over the T90. The fact that it weighs about 100 lbs more, and is 4 inches longer (5.125" in your case!) should not discourage you. I have a T98 in my 47 CJ-2A, behind the L-head, that came out of a 1960 Willys CJ-5 "trencher." While it is a bolt in, it's big, heavy, and the floorboards need modification. I don't know how you would ever shift one in an FC, but maybe there's a special shift cover???

Obviously, if I'm willing to put one behind an L-head, that should say something about the value of having a 6.2:1 first gear. It's also nice to know that you'll NEVER blow one up...wear it out, maybe, but no way to blow it up. They do shift slower, and rocking from first to reverse is a challenge.

You might consider going with the T-18 instead. It has the same case, and shares many parts, but is vastly more plentiful, and cheaper. The late model ones ('70's) also have reverse toward the seat, (instead of toward the dash) which makes the 2-3 up-shift easier. Otherwise, the T-18 can be found with the correct Dana-20 adapter, (easy machining for model 18) and the correct 6 spline output shaft. The input requires an adapter, and you need the correct input shaft.

Dave Blackmon wrote: The T98 is hands down the better of the two trannies, I have one of each ('61 FC170 w/T98 and '62 FC170DRW w/T90) and would gladly trade my Warn overdrive for another T98 in FC configuration.

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Matt Phillimore wrote: I goofed. I pulled the main shaft out of the input on the t-86 in the wagon. And you already know what that means. Now, what's the best way to get it back together after all those needle bearings fell out of there? Is there some trick, or is it just one of those things that's going to take a lot of care and patience?

Keats wrote: I'm not familiar with the t-86, but if its similar to the t-90 you may be able to slip the main shaft out of the case thru the rear bearing hole, put the rollers back in the input shaft and use heavy grease to hold them in place, and carefully reinstall the main. If I remember right that's what we did we my t-90. Hope it helps, Gary

Parshall Theodore J wrote: Hold the needles in place with an oil soluble grease like petroleum jelly. The grease will "glue" the rollers in place while you gently insert the shaft. Very shortly after starting the machine, you want the grease to dissolve and allow the oil to lube the bearings, hence, oil soluble grease.

Ron C wrote: Who hasn't had that problem??? What you need to put the needle bearings back in is lot of wheel bearing grease. When I say a lot, I mean coat the inside of the race with grease so the needle bearings will stick there. Patience is also recommended. I just put back the lower cluster on a T-90 where there is 4 rows of 22 needle bearings. It went well though.

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MVP The Herb Farm forwarded: Got a situation. About a year ago I rebuilt my T-case back to stock. (including the interlock pin) Now I've learned that if I'd had left the interlock out, I would have been able to use two-wheel-drive, low range. This sounded like a good thing. It's been a year since I put the case together, so I got to looking at the explode diagram in the manual and decide if I remove the levers and front ouput yoke and the piece that hold 'em, I can pull it off over the shift rods and remove the inter lock. Uh-oh. It came out about a 1/2" and now won't go either way. The 4wd shift rod still slides back & forth but the high/low barely moves. Any suggestions? Can't get it apart or back together. I haven't been able to work on it this week but I work on it tomorrow. Thought I'd try to get some insight. Thanks

Parshall Theodore J wrote: Be very careful in what conditions you use 2wd low range. The reason you could not get 2wd low unmodified, is the factory desire to "share the load" between two axles, minimizing the possibility of twisting off drive line components. Low range multiplies the torque transferred, and two axles will handle that load better than one. Granted, under just the right circumstances, you may have the same load case in 4wd, but the key word was "minimize".

MVP The Herb Farm) forwarded: To those that were interested; Just quit working on my transfer case and finally got out the interlock pill. I learned a few things along the way.

1. You can remove the interlock by just taking off the front output/shift lever tower.

2. You don't have to remove the shift rod seals or the front out put seals. (I did unfortunately)

3. Found a real cool and easy way to remove the shift rod seals.

4. Trying to hammer in new seals will wake the 6-year-old daughter who sleeps in the room above the garage.

5. I do a lot of un-necessary stuff when I'm frustrated.

6. Patience is a virtue that I was blessed with very little of.

This could probably be done without removing the transfer case from the vehicle.

First thing I did was remove the shift levers. Good move but I think it would be best to put it in 2WD and neutral first. I think this is the position that finally allowed me to remove the shift tower/output cover.

Next I removed the bolts that hold the springs/poppet balls. I think I should have removed the bolts holding the tower to the case first. In fact this may be the first thing to do. I think that would minimize the shift rod movement once you remove the levers and poppet balls.

Now the whole she-bang should just pull off. Not what happened to me. Since I didn't have my rods in the right place the interlock pill was catching on the high/low rod and the tower. It came out about a half inch and hung up. At this point the tower had less than 1/4" of movement. The 2/4 wd rod would move it's full range but the high/low would barely move.

After trying every combo with the lever while holding the whole case at every possible lever. I started getting frustrated and removed one of the rod seals with a screwdriver to see if anything under it was holding up the works. Nope.

Took off the drain cover to see if anything in there was queering the deal. Nope.

Thought that if I shot some compressed air in the poppet ball hole it would move the interlock pill over. Nope, but this shoots the shift rod seal right off the rod. Have to remember that trick for the next rebuild/reseal, that was cool.

Thought maybe there was a snap ring under the front output seal. Nope. (New seals are a lot harder to remove than old rusted ones. Too much work for no gain.)

I was just about to quit for the night and I had the case lying on its back with the rods pointing up in the air. Tried playing with them one more time. CLUNK! They seemed to find common ground, hmmm.

Gave big yank on tower/cover, fall on ass, parts flying all over. Whoops didn't have to pull hard.

Used magnet to suck out interlock.

Found out it was too late to install seals and had to give up for the night. Much happier person now. I hope I use two wheel/low a lot!

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Richard Grover wrote: What did you do to your t-case? I haven't pulled mine apart and don't know that I need to. My rear output bearing was a little loose, but since it is a taper roller, I pulled the bearing cover off and I'll put it back on without a shim or two. I seem to remember hearing of people upgrading the internal bearings from the needle bearings to taper roller bearings. Has anyone out there done this?

Jeff Gent wrote: Timely, I was thinking about this a bit last night, I've just started to tear down my spare xfer. There is a kit, another AA one I think, where you have to machine the shaft and intermediate gear for roller bearings. Dale Chaudiere has one of these I believe so I'll let him fill in the details Check out for some rebuild info.

About this mod, I've been told that a main reason was to quite down noise from the xfer. I've also been told that most of the noise comes from the T90 and that swapping that out helps a lot. Can anyone confirm or deny this (as in the noise did/did not drop when you lost the t90 but kept the '18)? Something to think about as well is that I understand the stock setup to be rather easy to do (in the field is possible according to the above page, I'll reserve my opinion until after I finish the rebuild) and possibly a lot cheaper than with the mod where you would have to get another shaft and/or gear machined if you need to replace them. The only thing at this point that would sell me is a significant strength improvement, which I'm not convinced of yet.

Rod Smith wrote: I replaced the needle bearings with the Timken roller bearing upgrade on my 71 CJ5 about 20 years ago and it has never been opened up since. The roller bearings reduce the noise from the TC when on the highway. I thought about doing it on my 59 pickup when I rebuilt it but the kit is now about $100 so I decided not to since I don't drive the truck that hard.

Acontoni wrote: Richard, I completely disassembled the transfer case and cleaned everything in a solvent tank. I sandblasted the case and all covers. Then reassembled everything, lightly coating all bearings and surfaces with Slick 50 gear lube. Correctly (aircraft style instead of bailing wire) safety wired the internal shift fork hardware. I replaced the intermediate shaft and its roller cage bearings with a kit from 4 Wheel Parts Wholesalers as well as using an overhaul gasket and seal kit from the same company. I do not recall any needle bearings in my 1 1/4" intermediate shaft spicer 18 case. I also plan to come up with some type of overflow tank coming from the vent to collect the expanding gear lube that is generated from the heat and not blowing out.

The excessive noise does come from the transfer case and it also generates a lot of heat, and is not recommended to be towbared without disengaging both axles or removing both driveshafts.

My intent is to build a dependable family trail ride vehicle and have a basically stock appearance body and drive train (You guys will probably cringe)-with exception to the 3" Rugged Trail (Warn Black Diamond) suspension lift and 35" BFG Mud Terrain tires and a roll cage. I want to gain clearance and help compensate those 5.38 gears. This will pull the M416 Trailer with the camping gear. 

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Merl wrote: Speaking of heat in a Spicer-18, my local Jeep guru told me last week that Amsoil synthetic 90 weight gear oil would keep a Spicer-18 cooler. He had some in a plastic bottle, looked very thin but he swore by the stuff. Anybody ever use this stuff?

Rob wrote: I don't know about running cooler but since I rebuilt and switched to AMSOIL I can barely hear any noise from the xfercase at all! Highly recommended!!

acontoni wrote: I have heard great things about all the Amsoil products but decided to go with all Slick 50 products in the form of gear lube, oil, grease. I have found all the products at the local Walmart. Has anyone used Mil Spec silicone brake fluid in place of DOT 3 fluid in their projects? I know that's all we use here in our M series Military vehicles. They sit for long periods of time and moisture contamination has not been a problem. Does anyone know if any of the other Willys vehicle master cylinders that have a dual reservoir will bolt up inplace of the single style in the 48 2A? I'm planning a 4 wheel disk set-up using 1/2 ton chevy 4wd components and would like to still have brakes if one axle develops a leak. Art,IL48 CJ2A in deep frame up rebuild

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Richard Grover wrote: My transmission is out of the Willys and I'm taking it apart. Why? Well it is working OK, but it destroyed the pilot bushing in the flywheel in a little over a year, so the experts tell me the front bearing of the Tranny is probably bad. Any advise for me while I'm in there?

Ron Cox wrote: Yea, go ahead and replace the sincro gears if you haven't in a while. You might as well do it when it is already down. I would also replace the rear main at the same time. Inspect the main shaft where the needle bearings ride for any wear and mic the shaft for true roundness.

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Steve Guenter wrote: Hi folks, I new to this list as well as the "Willys World". I recently brought a '61 Willys 4WD PU with original engine and trans, in fairly good condition. However, the shift levers for the 4WD have a loud rattle. A local "jeep expert" told me that I'm missing a tension clip that reduces the rattle. Does anyone know where I can get this clip, or any other ideas to reduce the noise?

Wehbee wrote: In the mean time, rap a heavy rubber band around them. Worked for me.

Richard Grover wrote: I picked up a spring clip up at a local old Jeep shop, 4 Wheelers Supply in Phoenix. I'd imagine they are available from several sources. Take a look at my Parts Sources web page if you don't know of a shop near you.

Uncle Mike wrote: I just fixed a rattling transfer case shifter on my 77F250. The little plastic insert had broken up and fallen out, leaving a lot of slop between the shifter and the bolt that holds it on. I took the bolt out and wrapped it with Teflon tape to roughly the same thickness of the old plastic insert. Now its nice and snug again, and more importantly, no more rattle.:-)

Richard Grover wrote: Plastic? What's that? Not much plastic on my '49. Spring steel clips go on the pivot pin of the levers and put sideways tension on the lever an inch or two above the pivot.

Marshall Rimland wrote: Whenever I do a grease job, I squirt a little grease between the rubbing surfaces of the levers. This Quiets them down somewhat. Use a needle tip.

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Chuck Pedretti wrote: Any idea how you install the bearings inside the cluster gear between the shaft it rides on? The only thing I can figure is that there must be a short shaft that you use to install the bearings around outside the transmission and then push it out with the real shaft once you have the assembly inside the transmission case. I know if I had an original repro manual it would tell me what I want to know. I promise to buy one next time I go to Willys Mpls :) Thanks in advance. P.S. Dual chamber MC project halted temporarily until I trans & chevy bellhousing installed to check clearances. I'd hate to get it all done then find out it doesn't fit!

Jeffrey Gent wrote: I don't have a manual, but when I took that apart for you I wished I had a wood dowel similar to what you described and how it is called for in putting the '18 xfer together. I pushed the shaft the wrong way the first time and some of the bearings got in the way and it took a while to get it apart. I would look for/make a wood dowel with a slightly smaller diameter than the steel shaft and just smaller in length than the gear. You should then be able to assemble the bearings inside the gear, holding them in place with the wood dowel. Then insert the gear into the housing and push the dowel out with the steel shaft. Champfer the edges of the wood dowel and clean it up so that nothing catches those bearings or the rings. There was a brass bushing that went in there as well so I don't know if that will be a pain or not.

When I rebuilt my OD the bearings for the planetary gears were held in place with grease. It had enough sticking power to hold everything in place until I got the shaft installed.

Richard Grover wrote: Yes, the manual references a special tool to load the rollers into the cluster and hold them while putting the cluster into the case (W-193 for F4 and W-166 for L6). Of course, no one has even seen one of these for 25 years, let alone know of a source to buy one. Eric Lawson cut off an old shaft and drove it out through the front with the new one. The front hole in the case is .002 smaller than the back hole, so the shaft doesn't go out the front without considerable force. I didn't have an old shaft, so I used a 3/4" dowel coated with heavy grease. If you got some slivers off the dowel, it could be bad for the bearings, so be careful. It is like a Chinese puzzle. You have to put things together in the right order or they don't go. If you need instructions, let me know. I have the manual and I had my T-90 apart a couple of months ago.

wohleb wrote: The wheel bearing grease trick worked just fine for me on the cluster gear. I assembled with lots of grease using the shaft then slid the shaft out carefully, placed the gear in the tranny and then slid the shaft back in. The local HS auto shop teacher has all his students do it this way to pass.

Chuck Pedretti wrote: Thanks to all for help with T-90 bearing questions. I tried the packing with grease and removing shaft before installation method and it works great! Total assembly time 2 hours & 1 beer. I have some observations on parts I bought from JC Whitney & Rubicon Express and thought I'd share. JCW - small parts kit for T-90: $20 Contains everything you need, bearings, gaskets - far cheaper than the Beachwood kit which is about $20 for the parts & 10 for the gaskets. The only catch is the front oil seal, it is for the short shaft T-90, so if you have the long shaft you'll need to get one separately.

JCW - syncro repair kit $20, 2 blocking rings, 3 syncro blocks, 2 springs everything you need to fix your syncro problem

JCW - drag link $20 what a piece of junk! the grease fittings wouldn't go in part was rusted at the welds where the cruddy paint had fallen off. Just as well, I have an early 46 cj2 so I need a different drag link (my bellcrank 'knob' faces up.

JCW - bellcrank repair kit - looked OK but had to return, it is for the later 46 & up cj also mine is much smaller.

Rubicon express 2.5" lift kit: these springs are stiff! I think they are the warn units, kit comes with u-bolts shims 4 procomp 1000 shocks and 4 leafs with poly bushings. Only complaint is that the bushings use smaller than stock leaf bolts which don't come with. You need do drill the holes in your shock plates out to 1/2" so the U-bolts fit.

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Merl wrote: When I shift at speed the T-90 is a little more difficult to get into gear than I would expect, but as long as I shift s-l-o-w all is well. If I try to shift like a normal car, directly from second to third for example, I get the big grind. When I *ease* it out of second gear, let it ride in neutral for a second or two, then ease it into third (steady pressure, don't pull too hard) it has no grind. Similar symptoms going from first to second. The T-90 in my 2A is both looser and easier to shift with less of a tendency to grind (except when going into first).

Chuck Pedretti wrote: I think I can answer this one, it sounds like part of the synchronizer is worn out. The brass blocking rings tend to wear out and not capture the synchronizer plates. When this happens the transmission behaves like an unsynchronized trans which means you push in the clutch, wait for stuff to stop spinning and it slides in. JCW sells a kit to fix for $19.95 which includes new blocking rings for 2nd & 3rd

Merl wrote: Is that the sort of thing I can verify by popping the cover and visually inspecting?

Chuck Pedretti wrote: Unfortunately not, the wear occurs on the facing surface of the blocking rings where they touch the synchronizer hub. The only way to look at the wear is by pulling the transmission or pulling the t-case off the back and separating the input & output shaft.

Jeffrey Gent wrote: I think you might be able to see it. When I pulled the tranny apart to send Chuck the guts the synchros were VERY bad, two dogs were missing. Pop the cover and you may see a bit. If the dogs are slipping over the synchros, then you should be able to see some grooves in the surface of the synchro rings by pulling the synch assembly to one side (ie, shifting it) and looking through the slots for the synchro dogs at the one ring and then pulling things to the other side and looking there. A bit vague perhaps but I can clarify what I mean if needed, it should be clearer once you look inside. Unfortunately, Chuck has my hard parts now so I can only work from memory (not my best suit) on details of the T90. By the way, if you have to separate things to see it, you're over 1/2 way through a rebuild so you might as well complete the job or at least plan on changing out the syncros, a one-banana job.

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Chuck Pedretti wrote: Ok, I bought a manual and it doesn't answer this one for me. The nut on the end of the transmission output shaft (T-90) appears to be a 1 9/32 because my 1 5/16 is too big and the 1 1/4 is too small. Where in the world do you get a wrench for this? I can't get an adjustable in there.

Stephen_J_Perialas wrote: Chuck, I have modified a 1 1/4 to fit by using a cheap 1 1/4 and grinding on BOTH surfaces, it wont fit snug in all areas, but it works. Ya never know ,you might need it again sometime.

Richard Grover wrote: I took mine off OK, and since I only had a 1 1/4" and a 36mm, I'm guessing the 1 1/4" fit it. (36mm is bigger than 1 5/16".)

R Cox wrote: Chuck, I used a 6 point 1-5/16 socket. I don't remember a problem so it must have worked. The 6 point gives it a lot to grab onto still where a 12 point doesn't.

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Glenn Goodman wrote: Don't know if you can read this but you should be able to bolt the assembly right in. It's not very thick. The only way I can describe it is that it looks kind of like a flat bottom bowl with straight sides and four holes in the bottom. Bolts right in behind the xfer case and the brake "strap" fits around it. Hope this helps.

Rick Stivers wrote: Glenn, Funny you should mention the brake strap. My 48 CJ-2A has one mounted like that. Last week I bought a 1965 manual for my JP it shows a dual brake shoe setup inside a brake drum on the back of the Transfer case. I was about to think my external was a homemade setup because I couldn't find it in the book. Does anybody know which vehicles came with which setups?

Steven Dunlop wrote: The MB and very early CJ-2as had the contracting strap. Very early on (sometime in '46) they switched to the dual shoes inside a drum. The dual shoes in a drum mechanism is less prone to overheating so can serve as an emergency brake as well as a parking brake.

Rob wrote: My 63 wagon has this "great" setup. The owners manual (1962 copyright) shows it as an option.

Merl wrote: Funny, I used to think I knew a good bit about these beasts. But, the list continues to prove to me that I actually know very little. I thought they ALL came with the drum and dual shoe setup. My late '46 2A has the dual shoe and drum, but I added that shortly after I got the Jeep so I know these weren't the original parts. To answer the original question, my drive shafts worked/works fine with or without the e-brake.

Donald Tarczy wrote: My 42 GPW has the band type, I think it was standard on all GPW/MB

Tim Lankins wrote: Hate to tell ya but both of my 48's have the drum type . so maybe a previous owner changed it? Luck

Jeffrey Gent wrote: If you use parts from an axle such as came out of my '62 Wagon then you will have built in e-brakes. The handle for mine is a lever at the drivers left knee. I don't know if it's a straight bolt-in or not.

Merl wrote: I put 11" brakes on my 2A with every intent of using the ebrake assembly in the rear drums. Haven't gotten around to it yet though. My M38A1 came to me with 10" Jeep drums all around and includes the foot operated ebrake pedal that is in the standard place at the drivers left. The seller told me that this was the CJ-5 setup in the late 60s, and it looks like there were no modifications needed to mount the pedal and release handle assembly (other than an extra hole or two to drill). It works well, is solid because its factory for the CJ-5, and doesn't really look out of place. I would imagine that you could do a direct transplant from a late 60s CJ-5 if you can find a donor.

Donald Tarczy wrote: If you use the 11" brakes from a 71-75 cj5 it would be an exact setup as it used a 44 rear end with modern brakes with self adjusters and drum emergency brakes it actually has to be early 70s (post AMC but pre AMC 20 axle) the 60's still had the TC setup

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Frank Wood wrote: It's back to the salt mine for me tomorrow. I just about finished my chassis over the holidays. Yeehaaa. I'm knee deep into my transfer case now. I've never seen the inside of a transfer case before. Doesn't look too bad so far. All of the gears look OK. I have a 29 tooth main gear and 1 1/4" intermediate shaft. The manual is telling me to remove the poppet plugs on both sides of the front bearing cap. They aint budging. Not much of a head there to get a purchase on. Any suggestions from the Willys Techers? Any advice for the rookie would be greatly appreciated. Hope I don't have to easy-out them.

Rick Stivers wrote: Frank, I haven't been into my T-18 yet, but I have experienced this type of problem before. If they are a shallow hex headed bolt like I have found before, a standard socket can't get enough purchase to remove them. If you look at the end of the socket there is usually about a 1/16" inset before the socket can grab. I have three 6 point sockets that I have modified just for these type of shallow bolt heads. All I did was grind the lip off of the socket so they could grip lower and they work great. Since then I haven't had a problem. I hope this helps.

Frank Wood wrote: Great idea Rick, I'll give it a try.

Ron Cox wrote: Frank, I have just torn my xfer case down also but I am not going to take the main gears out. Since I had it off the tranny, I went ahead and ordered all new seals and gaskets. I am in the process of sand blasting it and then I will reassemble it. Let me know how yours goes.

Frank Wood wrote: Hey Rick in SA, I tried your trick grinding the beveled lip off of my socket and it was a smashing success.

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Chuck Pedretti wrote: Here's a question for those of you using the Advance adapter for a Chevy to T-90. Is there supposed to be a bearing between the release bearing sleeve and the adapter plate? It looks like the adapter is machined to accept one.

Rick Stivers wrote: Chuck, Mine doesn't have a bearing there but that doesn't mean there isn't supposed to be one. The guy that modified my truck before I bought it was a professional mechanic. He did a very good modification before he turned the truck over to his brother. I'd be very surprised if he left something as important as a bearing out. And if one does belong there, it seems to work fine without it.

Rick Stivers added later: There should be no bearing between the release bearing sleeve and the adapter plate.

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MODEL - 18 = 26 OR 29 TOOTH?

Jack Starcher wrote: How can I tell if my Model 18 is a 26 or 29 tooth version? It's out of a '46 CJ2A. Do I have to get in it and count? If so, which gear? I'm assuming I'd just have to pull that rear cover, right? Wrong? Is there a way to know with out cracking it open? (I've had it apart twice now, don't relish the thought of a third time.) Yep, I'm interested in the OD too. Looks like I'm at a disadvantage though since I was in digest mode. Oh well, I need to know which one I'm looking for anyway.

Jeff Gent wrote: You need to know the number of teeth on the input gear on the xfer. Popping open either cover will let you see the gear, but if memory serves the number is stamped into the gear itself and this can be seen via the PTO portal so you don't have to actually count them and may be able to avoid even draining the oil. Shouldn't be that hard. I'm sure someone around here knows what versions were used in which rigs, but you have to assume that no one's changed anything in the last 53 years.

Actually, I was cleaning up the case last night getting ready to put it all back together an noticed on of the numbers stamped in the case, nest to the Dana symbol I think, that had a few numbers and then a 29. Believeing that I have the 29 tooth unit this may be some indicator of this. A big guess on my part.

Merl wrote: Check out it might give you a little more information. If what the page says is true, if you have a 1 1/8" intermediate shaft you have a 26 tooth, 3/4" is a 27 tooth, and a 1 1/4" is either 26 or 29. I know this held true for my '46 2A, its got a 1 1/8" intermediate shaft and a 26 tooth input gear. But I can't confirm if my TC is original or not.

Dave Blackmon wrote: Here is the info I have...... Checking the intermediate shaft diameter is a quick, easy way to identify what vehicle a transfer case was originally used in. Keep in mind, however, cases that originally had the 1-1/8" intermediate shaft and caged rollers may have been machined to accept the 1-1/4" shaft and uncaqed rollers, because of the superiority of this later style bearing. There is only one sure way to identify what the transfer case is - count the gear teeth and number of splines on the input gear.

MB AND GPW MODEL JEEPS: 3/4 dia. intermediate shaft, cage type shaft roller hearing, 27 tooth input gear with 6 spine hub, 80mrn locating bore in face of case. 27 tooth gear was used only in MB and GPW model Jeeps. This model 18 transfer had a low range ratio of 1.97 to 1. This is only found on MB and GPW model Jeeps.

1946-1955 CIVILIAN JEEP UNIVERSAL WITH 4-CYLINDER, 1946-1955 UTILITY TRUCK AND WAGON WITH 4-CYLINDER AND 6-CYLINDER 161 C.I.D., M38, M38A1, M-170 MILITARY: 1-1/8" dia. intermediate shaft, cage type shaft roller bearings. 26 tooth input gear with 6 spline hub. 80mm locating bore in face of case. This 26 tooth gear may be marked 18-8-19 or 18-8-31.

1955-1971 JEEP UNIVERSAL WITH 4-CYLINDER, 1964-1969 JEEP UNIVERSAL WITH FACTORY OPTION V6, 1955-1962 UTILITY TRUCK AND WAGON WITH 6-CYLINDER: 1-1/4" dia. intermediate shaft, 48 uncaged rollers, 29 tooth input gear with 6 spline hub. 80mm locating bore in face of case. This 29 tooth gear may be marked 18-8-23.

1969-1971 JEEP UNIVERSAL WITH FACTORY OPTION V6: 1-1/4" dia. intermediate shaft, 48 uncaged rollers, 29 tooth input gear with 10 spline 1-3/16" dia. hub. 4" locating bore in face of case. This 29 tooth gear may he marked 28-8-50.

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Vern Stark wrote: Does anybody need to change the fwd driveshaft seal on a model 18 transfer case? I did mine several months ago. I ruined several seals trying to drive them in with the protruding shaft in the way. Then I made a very simple tool to drive the seal home. It is just a piece of old fence post from my firewood pile. I turned it down on the lathe and bored a hole in the end to clear the shaft. Expecting I might crack it, I made a spare since the lathe was all set up.

Last night I was cleaning up some debris from previous projects and came across my spare sitting there. Does anybody need one? I'd be glad to drop it in the mail to you as a present, as long as you promise not to send it back. Remember it is basically just a piece of firewood to me, but it sure did the job nicely. If more than one person needs one, I could crank out about a dozen in an hour or so, just to keep some old rigs on the road. Others have done similar things for me and I would be more than happy to return the favor.

Drop me a line with your mailing address if interested. Sometimes it takes me a while to be able to respond so don't be alarmed.

Note: Vern was good to his word and made about 20 of these tools and sent them out free of charge. I think he's done now so please don't barrage him with request. I am sure that some of the recipients of these can be coaxed into passing them on. Thanks Vern.

Jack Starcher wrote: Hi guys, been away from my computer for a few days and just finished reading through several digests and thought I'd make a few comments. While I'm sure the Vernomatic Sealer 2000 (did I get that right?) <g> will work excellent, I though I'd pass along my own trick for seal driving. I use various sizes of PVC pipe and couplings to make up drivers. I've got a bunch of miscellaneous pieces laying around so I can generally find something that'll work. If not the couplings are cheap at the hardware store. Just use a rubber mallet and it works pretty good.

Chuck, to get that seal out I carefully ran a self tapping screw into the top layer of the seal and used vice grips to pull it out. Had to do it in a couple of places and ended up ripping the old seal to pieces, but I got it out.

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Ross Cook wrote: Does any body have any info on remote positioned model 18 transfer cases or parts to convert an existing T18 to a remote position?

Reed Cary wrote: What are these off of? Where used? Sure I'm not alone, wondering.

Ross Cook wrote: I'm not sure if there are any. They might have been set up in old broncos or scouts. I know that Advance Adapters sells one. Thought there might have been a Willys configuration. Basicly, Instead of being married to the back of the transmission. There was a short drive shaft between the transmission and the transfer case as in some of the old Dodge military trucks. Thought if I could find one I could try a couple different power combos without having to add tranny adapters.

Jim Kyser wrote: Ross, Advance Adapters sells kits to convert either a model 18 or a model 20 to divorced configuration. The kits list for just under $500, but many of their retailers sell below list. 1-800-238-700 or

Reed, I don't know of a factory configuration for one of these, but AA says they were used in a lot of the early '70s mini-truck 4wd conversions before there were OEM 4wd mini-trucks.

George Steele wrote: The remote model 20 was used in the 70's in Datsun, Toyota, Mazda & Minie Ford Pickups. We did a 68 Datsun that way in about 1972.


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Merl wrote: This Jeep has a Buick 231 adapted to a T90, so I've got one of the long main drive gears. The problem I'm trying to solve is...after the Jeep is driven a few miles and things warm up, I have to shift really slow and easy into 2nd and 3rd to avoid grinding the gears. After some further disassembly, everything *inside* the transmission looks really good. Even the syncros. BUT...I took the main drive gear out and just stuck it into the flywheel pilot bushing and there's a lot of wobble. I have a new pilot bushing (not installed), the shaft has a little wobble on there as well. I've got a new main drive gear (never used... broken teeth and can only be used as a clutch alignment tool), with this on the new pilot bushing I get a nice snug fit, no wobble at all. All this together makes me think I need a new main drive gear and pilot bushing.


1) Given a wobbly long shaft main drive gear, should I be looking at replacement of the front bearing? Anything else?

2) Someone posted the other day about the long shaft conversions on a T90 causing pilot bushings to wear out faster, anybody know why this happens? Could I have a bad engine/bellhousing alignment? How would I check?

Ronald L. Cook wrote: Merl, I would guess your synchronizers are not all "that good". Your lubricant in the transmission is thinning with heat and that lack of resistance may be why you have to shift slow to avoid grinding the gears. Just a thought, there.

You need a good snug fitting pilot bushing, a straight input shaft, a good front bearing, a good input bearing, a good fit from input to output shaft after bearings are installed, and a good output main bearing. Any slop in this main shaft and sooner or later a problem of some kind will develop.

It definitely sounds as if your input shaft or possibly the whole transmission has been running out of alignment all right. It could just be the result of loose bolts, or the adapter plate is off. The input/output shaft of the transmission has to be perfectly in alignment with the engine crankshaft and be mounted up in such a way that it will stay aligned. I don't really know an easy way to check the alignment.

The most overlooked bearing and surfaces are the input bearing and input and output shaft bearing surfaces and the pilot bearing/bushing. Any play coupled with a bad or chattering clutch and you soon have a bad main shaft bearing and then everything bad. Also, the reverse can happen and the poor bearings, etc., can cause the clutch to start acting up. Just a long-winded bunch of free advise from a pilot(no transmission in my airplane). Good luck Merl.

Reed Cary wrote: Merl' On the alignment question, two thoughts come to mind: 1) if alignment has been a problem, the bushing should be bell-mouthed. You'd have to measure it with a telescoping gauge and mike (or similar) to tell. 2) with a new bushing in place, I would think that an application of bluing might reveal a pattern to tell you about your alignment.

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Jon Paulsen wrote: Willys Works has the kit, but it's different than you describe. Their kit looks like a big snap ring with the ears cut off. It comes with instructions and says it is to fix the problem of popping out of gear under deceleration. I ordered a kit and never used it, because it turned out my poppet spring was broken. New springs and balls for the tranny and new springs and cross shaft for the t-case levers sure made it feel like new!

Arne Anderson wrote: Curious how hard it is to install this quick fix kit that you described. Meaning the big snap ring one mentioned second.

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Matt Phillimore wrote: I removed the tranny/transfer case from my "new" truck, and cleared off the mud and muck, finding a plate on the top of the transfer case. My CJ5 transfer doesn't have a plate like this on it, but instead, Spicer is cast into the back in a diamond. Did Spicer change the way they did things at some time or something? just wondering, since no two parts I see are alike.

Richard Grover wrote: My Spicer 18 has a shiny, diamond-shaped metal tag attached with space for a serial number, which is blank. I believe this is the 1949 original t case.

Matt Phillimore wrote: Rick-is yours on the top of the case? Mine's got a rectangular plate, about 2X4, on the top, has a model number, space for the gear ratio, and the serial number, at the top left, it says Spicer, and at the bottom left, it has a half circle with the words "Brown lipe" across the top of the semicircle, and "gearboxes" at the bottom, straight across. All of the data is on the right side of the plate. Does anyone else have a plate like this? Thanks.

Jerry Lewis wrote: I have a D18 transfer case from a '46 2a with the rectangular plate that sounds identical to yours Matt. I've never seen a diamond shaped tag before.

Richard Grover wrote: I must have been delirious there for a few minutes. Mine is rectangular (but it has the diamond logo on it :-)

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Chuck Pedretti wrote: Is it normal for the shift fork bolts in a Spicer 18 T-case to be drilled and secured with safety wire. Mine were, and I'm wondering if it is necessary or if locktite will work OK. Also the front output "cone" bolts were secured in a similar manner. My manual mentions nothing about this, is it normal?

Getting ready to re-assemble the t-case after a good cleaning and a couple of new parts (intermediate shaft, roller bearings, thrust washers)

Ron Cox wrote: Chuck, It must be normal because my transfer case also had the safety wire on it. I plan to put it back on for what it's worth.

Merl wrote: Yeah, the front cone on my TC had safety wire too. Not sure why though, doesn't seem like it would need them there. But Ron is right, the safest bet is to put it back on...can't hurt.

Rob wrote: I have a hunch that this is the military version? My 63 does not have safety wire but my 51 has the wire on an olive drab xfercase with stenciled numbers ala' military.

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Rick Stivers wrote: I have a 62 Willys Pickup and I'm looking for a spare T-90, T-18 and OD to rebuild and swap into my Truck. I want to do it this way because I don't want to have my truck out of commission for more than a week. Anyway, Yesterday I was offered a T-90A-1 transmission, transfercase, and emergency brake assembly from a 1964 Jeep Wagoneer. The body of the transfer case appears to be about the same shape as mine but the rear output for the axle is coming out where my OD bolts up. I don't think this will be usable on my truck. Does anyone know what case this is or how to ID it?

The emergency brake assembly looks exactly like the one in my repair book for my CJ-2A. If it is, this my be a good source for those of you looking for some. I'm pretty sure this one has a home now. :-) My question revolves around the T-90. It has a model or part number embossed on the drivers side at the top. The number is T-90A-1. Will this thing work in my truck? My truck came with the L-226 but that was replaced with a 350 and a bell housing adapter. How do I know without pulling it out, if it was a long shaft or short shaft tranny? Any help you guys can give me will be appreciated. If it will work I would love rebuild it and have it on hand. The 350 is hard on them.

Matt Phillimore wrote: Sounds like a Dana model 20 rather than the 18. I had one in my truck when I got it. Thinking about putting it back in, especially if I never find a correct rear axle, sinc mine's not offset.

If your truck originally had a 226, it had a long shaft tranny. And no doubt, if you have a 350 and a bellhousing adapter, it is a longshaft T-90.

Rick Stivers wrote: Thanks Matt, Now what do I measure on the new T-90A-1 to determine if it is a long shaft and if it will bolt up to my T-18? Can the bellhousing be swapped between long shaft and short shaft trannies? Besides the shafts, were the T-90s built in different configurations?

Next Topic. Will my WARN OD work with the Dana Model 20? I'm only asking this because now I'm thinking it would be a good idea to keep the 20 around in case I blow out the Spicer 53 and have to upgrade the axle to a centered differential design.

Bill Prather wrote: Rick, I have been looking into the t90s and tcase for the wagon. from all the info I have received I have come to the conclusion that prior to 58 or 57 the t90a had the spicer 18 t-case after that they used the dana/spicer 18/20 which had several differences, ie the output on the18 is on the passenger side and on the 18/20 it is on the drivers side as for the transmission there should be no difference. If you have access to the t90 w/ the 18/20 we may be able to swap I have a t90 with the spicer 18. have some photos will up load when time allows.

GEORGEJEEP wrote: Rick, It does not take the expense of to many bad T-90's to pay for a T-18 that will last you the rest of your life. I put one in my 3B 24 years ago with a Buick V8. You can still keep your mod. 18 transfercase and your Warn overdrive. The T-90 out of that wagoneer is the same as yours.

Rick Stivers wrote: George, I did think for just a moment about replacing my T-90 with a T-18 but decided not to. My reasons are: 1. The T-90 that is in my truck has been there without a rebuild since it was new. The 350 was installed in 1980, so that means that it has held up to the 350 for at least 18 years. I can live with that kind of longevity. 2. I know the truck isn't stock, but I'm trying to keep as much of it that way as I can. I have admit to some slight embarrassment every time someone says "Does it have the original flat head" and I have to say no. 3. My 48 CJ-2A uses the T-90, so I'd like to learn as much as I can about these trannys as I can. 4. I never plan to do any "serious" off-roading in my truck, although I do admit to burning some rubber every now and then. If my plans for off-roading change, I will have to give more thought to the T-18 upgrade. Thanks for the info on the Wagoneer Tranny. I think I'll pick it up next month. :-)

Rick Stivers wrote: Bill, Do you have any info on how to positively ID this transfer case as an 18/20? Where is the ID or part number located? It does have the <SPICER> in a triangle just like mine on the back but I haven't been able to find anything that positively IDs either transfer case. If it's what you need and you have what I need I'm sure we can work out a trade. That would give me everything I need except the OD for my rebuild and swap. By the way I still want to come down to CC to check on your parts. Finances haven't allowed me to do it this month because I'm recovering from the holidays and some recent tool purchases. I believe Feb looks much more promising. I really do want that door handle. :-) I believe we can take the rest of this into a private E-mail. If you know how to ID this thing, let me know.

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Richard Needham wrote: There has been a lot of talk about overdrives for old Willys with Spicer 18 transfer cases. I have the opposite problem, and would like to lower the gear ratio in my Xcase. would like to do some rock crawling and trails. My Willys has all stock drive train components. Anyone out there that can help or has experience in this area.

Merl wrote: From what I've seen on the web the easiest and most popular way to increase your crawl ratio is upgrade your transmission. Seems like most of the upgrades I've seen leave the stock model 18 transfer case in place. If you go to the JeepTech section of you'll find a large section on Jeep transmissions and transmission upgrades. Since I've got a Buick V6 in my M38A1 and need to do a little transmission work, I'm considering the GM SM420. Just as a comparison to our stock T90 that has a first gear ratio of 2.98, the SM420 has a granny low of 7.05. That'd give you a big improvement in crawl ratio and wouldn't remove the possibility of still using an overdrive just in case you want to go faster than 45 mph on the road. There are other transmissions that may be a more desirable swap for you (maybe the T18), I'd start at Theres LOTS of good information there on this subject.

Keats wrote: In the recent past, there have been several tech stories in Four Wheeler Magazine and Four Wheel and Off Road and other magazines also, showing how to modify both the spicer 18 and dana 20 transfer cases by putting in different gears to lower the overall low range ratio. That would be a good place to look.

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Johnny M Stovall wrote: Pulled my 3 speed tranny & M20 transfer case out today>what fun>tranny not in the best of shape - can this be replaced with anything else or should I get started looking for parts>second gear and countershaft gear set, bearings a little rough.>I think the tranny is a T86AA ,Jeep is 67 CJ transfer case is in good shape

GEORGEJEEP wrote: Johnny, The 86 parts are getting a little hard to find but if you have a good T-90 you can take all the guts out of the 90 and put in the 86 case. The 86 & 90 have different bolt patterns on the front.

Keats wrote: In the recent past, there have been several tech stories in Four Wheeler Magazine and Four Wheel and Off Road and other magazines also, showing how to modify both the spicer 18 and dana 20 transfer cases by putting in different gears to lower the overall low range ratio. That would be a good place to look.

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Michael B wrote: OK, We've discussed OD 'till we should all be pretty up on what's available out there. Now, looking from a different angle I would like to know if anyone has any knowledge of a 4 speed solution. In particular a full synchro 4 speed. It would give an overdrive gear and make the machine capable of being down shifted to first without coming to a complete stop.

Chuck Pedretti wrote: Jeep Heavy Duty Four speeds - still no syncro for 1st gear and no OD 4th is still 1-1

T-98 Full Size Jeep

T-18 CJ-5 option

T-18A CJ-5 option

Aren't most 4 speeds lacking an Overdrive Gear? (unless we're talking automatics)

Michael B wrote: But if your other gearing is moved up so 1st is still produces the same end product as it does with the present 3 speed then you've had the same effect as adding OD to your 3 speed and you would have full synch if it is possible to adapt such a creature.

DG in Denver wrote: I spent $400 this fall to rebuild my T-90 and have the seals replaced in the transfer case. At the time, I thought the 4 speed idea would be great too, but did not have time to find the solution. My understanding is that in most 4-speeds you will get approximately the same gear ratio in low and high as you get in low and high with a 3-speed. There is just less difference going to second and third. I don't think 4th provides an overdrive, but 5th does. You would need an adapter for the 4-speed, I think that is the difficult part.

Rick Stivers wrote: Sorry my friend, 1:1 is still 1:1. Your top end Engine RPMs for a set MPH will stay the same. The only way to increase that once you hit 1:1 is to add an OD gear (0.75:1 in the case of the WARN of Saturn). So if top speed for your truck is 55 MPH now and you add a 4 speed with a top gear ratio of 1:1 your top speed will still be 55 MPH. You will just have more options in between.

Most people, that add the 4 speed, do so to gain a lower first gear. The T-90 has a first gear that is 2.79. Add this to my granny low and ring and pinion of 4.27 on my truck and my crawl ration is only about 35:1 (I did this from memory so if this doesn't sound right let me know and I will check the spread sheet at work). In granny low with my truck's 350 idling at 700 RMP I can still stall the truck using the brakes. This is inadequate for rock crawling. I would need to change the tranny to one with a lower first gear (maybe a 4 speed) and possibly change the ring and pinions to 5.38 if I wanted the truck for crawling. The bottom line is if you want to go faster you have to install something will go beyond the 1:1 final ratio or install an engine that can run higher RPMs.

Glenn Goodman wrote: No 4 speed I know of has an overdrive. The Ford T19 is synched all forward gears. The NV4500 is a five speed overdrive unit and the Dodge model can be had with FULL synch, front and reverse. The NV4500 is somewhat longer than the T19 and depending on the application may not be realistic. For a short jeep it would be very difficult to use, the rear drive shaft ends up being like 7" long. For longer vehicles it may be the way to go. Check out Advance Adapters for more info. You can order a general catalog from them and glean some good info from it. Good luck.

Jeff Gent wrote: So if I interpret this correctly, the idea is use a four-speed with a lower first then change the diffs to a lower numerical gearing. Yes, the effect would be an overall gearing similar to using the existing tranny with an overdrive. If you're mostly going to be on the highway this would be a good way to do it though it won't be much, if any, cheaper than buying an OD. Swapping in trannies is only a matter of time and money, Advanced Adapters has all the bits for what ever combo you'd want.

Glenn Goodman wrote: That's about it. It was once suggested I put in a T18 (T19 if I want synched forward) 4 speed, 33" tires and 4.27 gears. This would let me run at 65+ mph pretty well and still have a very low gear for crawling. Expense is the only thing keeping me from doing it at this time. Good luck, whatever you decide to do.

Mark C. Johnson wrote: There is one plus to the three speed that no one has pointed out and that is less shifting, heck most of the time in my CJ I just use 2nd and 3rd. When I drive truck I get tired of shifting all day in 7 and 13 speeds so why shift more than you have to?

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Brian Petry wrote: I was doing my weekly check of the oil level in my transmission and transfer case and noticed that the bottom of the overdrive is level with the oil fill plug on the transfer case. Given that, how is oil supposed to get into the OD? Do the gears slop enough oil into the OD to keep it happy or should I find some way to "overfill" the TC to make sure lube is getting into the OD.

Rick Stivers wrote: Brian, You have hit on the key to keeping a healthy and happy Warn OD. First, if you sit behind the T-case and look forward you will notice (as you did) that the fill line on the T-case falls just about at the bottom edge of the OD. However, if you continue to look forward you will find that the fill line for the T-90 sits about 1 1/2" higher than the bottom of the OD. That's why it is important to:

1. Keep the T-90 filled and checked often.

2. Not seal off the flow through for between the T-90 and T-case.

3. Never open the fill plug on the T-case to drain off the excess oil because that's what is keeping the OD lubed.

Dr. Vern wrote:  Dear Brian, To expound on what Rick said, there is an ingenious design that transfers oil to the rear portion of the overdrive. I have lifted a couple of images from Rick's D18 Rebuild guide to illustrate.

The first picture shows the protruding section of the overdrive removed from the transfer case. This view is looking aft. Note the black sheetmetal finger looking thingy on the right side of the picture. This finger is hollow and open at the top, forming a trough. This trough sticks into the transfer case and is nearly touching the outside of the planetary gear. Oil gets slinged (slung?) into the trough by the spinning planetary gear. From there, the oil flows by gravity into the rear section of the overdrive:

This second image shows what the OD planetary looks when installed in the transfer case. That oil trough slips in the narrow gap between the OD planetary and the housing of the transfer case:

The top image on this page, from Rick Grover's website, shows a cutaway view of a transfer case with the OD installed. It shows how the trough (labeled Oil tube) hugs the planetary:

I will second Rick's comment that low oil level will quickly kill an overdrive. The oil level doesn't have to drop very much before the rear bearing and synchro rings in the overdrive are starved for oil.

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This Page Last Updated 09 January 2001

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