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Axle Shaft End Float Measurement

Ring Gear Sizes

Axle Ratio And Top Speed

Unlock Hubs?

Rear Axle Bearing Cup Removal

Timken And Other Axels

Spindle Nut Wrench

Installing Locking Hubs On A Full-Floating Rear Axle

Floating Axles




Frank Wood wrote: If I ever get my chassis back from the blaster/painter, I have some brand new bearings/races to install in the axles. Also bought a shim kit. Wish I knew how to install them. My manual says to "remove or install shims to provide .003" to .007" end float of the axle shaft." What instrument do I need to measure this tolerance and how would I use it. Bearing installation seams straight forward enough but I would welcome any advice from the old... scratch that, experienced hands. Thanks

James Roney wrote: I have found two ways to set the end-play on those old axles. The first way (preferred?) is to go ahead and mount a magnetic base dial indicator and measure the end-play. Before I bought my dial indicator, I used to set them up this way:

Using a caliper or micrometer, measure each shim and sort them by size. You need to have at least two that are .005.

Put a large stack of shims under one side, and approximately the same amount on the other. The axle should float a lot, and have tons of end play. (clunk-clunk) Gradually remove shims from one side until the endplay gets less and less. Eventually, you will come to the point that there is a tiny little bit. At this point, remove one of the .005" shims. That should eliminate all endplay. If not, remove the other .005" shim. The goal is to find "zero." By using .005", you are guaranteed that you are between zero and (-.004") when the endplay goes away. At that point, add .008" and you're set! Don't forget to "even out" the shims on both sides once you've found the correct "total number". Also, it's important to "set" the bearing cups by giving them a firm "whack." (yes, on the threaded end of the axle, so use a wood 2x4 and leave the nut on the axle.) You should only have to do this once on each side when you start.

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jj wrote:

Dana 28: 6.625"

Dana 30: 7.125

Dana 35: 7.56

Dana 41: 8.5"

Dana 44: 8.5"

Dana 53; 9 1/4"

Dana 60: 9.75"

Dana 70: 10.54"

Fords (the axle name tells)

GM 10 bolt: either 7.5" or 8.5"

GM 12 bolt: 8.875"

GM 14 bolt: 9.5" or 10.5"

AMC 20: 8.75"

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Scott Little wrote: Would changing the axles from 5.38 to 4.88 do much to increase the top speed of my truck? Right now max comfortable speed is 50 with the 5.38's, what could I expect with 4.88's? Thanks for any info.

Rod Smith wrote: My 59 PU has 4.88's and I always wanted to shift one more time when it got up to about 50 MPH. The problem really is how hard you want to push the engine. My chevy 283 would be turning around 3000 rpm at 60mph.

The real solution was to install an overdrive. With a Saturn OD, I have no problem cruising a 65-70 mph and the engine rpms are well below 3000. Tire size also has a lot to do with top end speed! So, to answer your question, yes the 4.88's will be an improvement but an OD needs to be part of the project.

Rick Stivers wrote: Scott, Using the 5.38 geras, if your tire size is 28.5" in diameter and you are running the T-90 with the T-18 in 3rd gear, without OverDrive, your engine will be turning at about 3197 RPM at 50 MPH and 2398 with overdrive. In comparison if you were running the same combo with 4.88 gears at 50 you would be turning 2900 RPM in 3rd and 2175 in 3rd with OD. I have been assuming that you do not have an OD. Top speeds using your current max RPM of 3197 means you could reach 66MPH with an OD or 55 with the ring and pinion swap. I'd go for the OD and still maintain the low end creeper gears. Besides the OD will probably end up costing you less to install. I hope this helps.

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David Dodge wrote:
My dad has a 47 Willys Jeep that has the hubs locked into 4-wheel drive. He used it to pull boats to-and-from the boat ramp for over a year, and now they are locked in and won't disengage (by hand anyway). Any suggestions

Ronald L. Cook wrote: David--Have you tried jacking both front wheels off the ground? That should remove any pressure on the gears.

Rick Gray wrote: Dave, The hubs probably have had some moisture inside and has become corroded. A good way to fix this is to remove the bolts which holds the hub in place, remove the hub, and clean everything in a good solvent, coat everything with grease and reinstall. Its really not a difficult job. Just make sure that you replace everything the same way you took it apart. It may be a good idea to do one wheel at a time, that way if you need a reference for installation you would be able to use the untouched hub. You may have to cut another gasket for the hub to set on for installation. Hope this helps....

Steven Dunlop wrote: David, It depends what you want to do with the Jeep. Lockable freewheeling hubs weren't available until well into the '50s. So if you want a vehicle that's true to the original, take them out and put in a stock drive flange. On the other hand, you can leave them the way they are. You really don't need them unless you have lots of highway driving in mind. Just be sure to keep the steering knuckles and front axle full of gear oil.

If you really want them to work, you might have to replace them. They don't last forever, the best ones 5 to 10 years, tops, then the seals go and water and stuff get in and corrode everything -- then they jam.

You can get new ones from any good 4 wheel drive shop or from any of the major mail-order places for around $100 a pair.

If the hubs you have are still being manufactured, you might get by with a rebuild kit, which is much cheaper. The rebuild process is roughly similar to repacking wheel bearings, only there are a bunch of fiddly little springs and parts for the clutches.

Merl wrote:
Depends on what kind of hubs they are. My 2A has what I believe to be Allstate hubs, they're even easier than repacking bearings. No springs, clips, clutches, nada. Just two dowels that are rotated individually via a hinged flat piece of steel. Mine won't disengage until I take the Jeep out of 4WD and let the Jeep roll a little, this takes the pressure off of the hub's "innards". Good luck.

Ben Page wrote: Sounds like a rust problem. Pull them apart and do some praying whilst you're doing it<grin>. Hope this helps

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Frank Wood wrote:
Help! I finally have some free time to spend with my truck and I can't get the damned left rear bearing cup out of my Spicer 53. I've tried heat, chisels, penetrating fluid, I even put the axle nut back on and hammered on it with a crow bar trying to pry the whole axle out with the bearing cup. No damage or success yet. But I had to quit before I tear it up. Any suggestions? I am thinking about looking for a puller similar to the hub puller. One I can mount to the axle flange, then pull the whole axle out. Anybody done this? Thanks, Frank
P.S. Sorry for the win.dat crap attached to my posts. I have checked that MIME is off many times but I'm still getting the afterbirth. Gates must want me to upgrade to a newer version of Exchange.

Frank Wood wrote: Never mind. Slid the drum back on, screwed on the axle nut, and put the sledge to a two by four across the back side of the drum. It all came sliding out.

Merl wrote: I had this problem on my D41. Someone told me about a little more graceful way to get the race/bearing out that worked for me... take three longish carriage bolts (about 6") and screw a nut about halfway down each bolt. Insert the threaded end of each bolt into the holes of the axle flange. Put the hub back on, doesn't have to be tight, and put the axle nut back on (I used an old bent hub), the heads of each carriage bolt should rest against the inside of the hub. Loosen each nut so that they will tighten against the axle flange. Alternate between the three bolts, this puts even outward pressure on the axle pulling on the bearing which pops the race out.

I hammered, pounded, pulled, etc, etc, and nothing would get that race out of there until I tried the above. Once I did that, the thing came out quick and easy.

Ben Page wrote: I hate to be at "loggerheads" with any of my learned colleagues but this method has been known to crack the drum. Use the right tool for the job mate. The right tool is a sliding hammer<grin> Use a "sliding hammer". Hire one if you haven't got one. If you can't get one then do this. Using your cutting torch heat the cup until it's cherry red. Quickly place your torch down and using a cold chisel cut a slot into one side of your cup. Now heat it cherry red again and place the cold chisel between the housing and the cup right where you cut the slot. (You may have to have a few goes at cutting the slot). Provided it is hot enough you'll "lift" one side of the cup and the rest is easy:-). But do everything you can to make the sliding hammer work first. Even if you have to heat the cup before the insert the sliding hammer. OK? Does this help?

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Luke Schulze wrote:
Well this has probably been asked before but... This weekend I saw several 50's Willys pickups in a guys I had to stop. The one had a hydraulic dump bed (was that original-looked original). The rear axle bolted together as two pieces in the center...the was no rear diff cover...I had never seen anything like that before on a jeep.. what was it???

Rick Stivers wrote: Luke, Welcome to the list. The axle you saw under that truck is a Timken axle. From what I understand it is a very good axle, but it's rather difficult to find parts for. Rick Grover rebuilt the one in his truck and wrote an excellent article about it. Click on Timken at Rick's home page:
The pickups came with:

Axle Rating

4.27 Gears

4.89 Gears

5.38 Gears

Spicer (Dana) 44 3700 lbs




Spicer (Dana) 53 4500 lbs






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Chuck Pedretti wrote: Do you happen to know the JCW part # for the spindle wrench? I have never seen it in the catalog and I need one. Willys Mpls is on backorder for them. As far as JCW parts I agree, some are crap - those you return using the return label you get with each order, most of their parts are good and always a lot cheaper than everywhere else.

Tom Jacoby wrote: Chuck, On page 63 of catalog 622J, part 75dk3337t @ $9.99 is the Front Spindle Nut Wrench for all Jeep Universal.

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Vern Stark wrote: Does anybody have any info on adding locking hubs on a full-floating rear axle? Adding a full-floating rear axle is way down on my list for my 48 CJ2A but a guy I know has a rear axle for sale. I haven't actually seen it and he doesn't know what model jeep it came from, possibly an M38 but not sure. Nor do I know what R&P gearing it has, but I want to keep the 5.38 I presently have.

Pretty much the only reason I'd really want it is for the ability to add locking hubs, which would make flat-towing much easier. Is this an expensive modification, hoping the R&P is the same? Judging from other non-jeep full-floaters that I have worked on, it should be fairly simple but all my projects seem to start out that way and then take on a life of their own.

Any thoughts would be greatly appreciated. I'm still running the stock drivetrain w/flathead-4 so neither torque nor heavy 4-wheeling would be a factor.

Jerry Hunnicutt wrote: Hey Vern, I have been contemplating the same problem. If you do not have a full floating rear axle now, there are kits to convert it to a full floater. Then you can put locking hubs on. As far as flat towing, instead of a trailer you can use a tow dolly. That will solve the stability problem and you can get them with brakes. Depending on the size & weight of your tow vehicle you may not be able to afford the additional weight of a trailer. I think the tow dolly is the answer. Takes up a lot less room in a driveway or garage too. And has got to be at least half the cost of a trailer, even though I haven't priced one yet. Anybody out there purchased or used a tow dolly? I would like to know how well they work. Also, anyone done the conversion to a full floater on the rear end?

George Steele wrote: I did the full floater thing on my 62 3B in 1970. Have never had a problem

with it. I run a 300 Buick, T-98 transmission, 4.27 gears.

Ted Parshall wrote: I converted my '71 CJ-5 Dana 44 to a full floating rear a number of years ago. The full floating came from the desire to have disc brakes on the rear. The caliper mounts and spindles from a '76 CJ bolted right on (after reinforcing the flanges). Then it was only a matter of sending Strange Engineering a money order and drawing for custom axle shafts.

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Don Miller wrote: What is a full floating axle? What is a semi-floating axle??? This is mentioned in my CJ7 manual...noticed when I replaced all the axle seals yesterday. Thanks Don Miller North Carolina

Richard Needham wrote: On a full floating axle the axle shafts drive the wheels but don't provide any support for the axle bearing. ie: you can pull the axle shaft and still have the wheel on the truck. semi-floating .The axle shaft provides the support for the inner bearing race, or sometimes is used as the bearing race. ie: If you break this axle the wheel will leave the truck

Steven Dunlop wrote: Best place to start is with a simple axle and wheel, like the one on a trailer, where the wheels don't steer and aren't driven from a differential. On the simple axle, you've got two tapered roller bearings. Each one supports the weight of the vehicle. Because of the taper, the inside bearing holds the wheel in place, pushing it away from the vehicle and the outside bearing holds it in place pushing it towards the vehicle. The bearings run on solid spindles.

Full-floating axles are found in front of most older 4wd vehicles and in the rear of most 3/4 ton and up and a few more heavily built 1/2 ton. They work the same as a simple trailer axle except that the spindle is hollow, so that an axle shaft can fit through it. The axle shaft has a splined end that engages with the gear in the differential (on a rear axle) or the CV joint (on a front axle) and a drive flange that bolts to the wheel. The axle shaft is considered "floating" because it is not affixed to bearings on either end.

Full-floating axles support heavier loads because the bearings are placed in line with the inside and outside of the wheel. They can be identified by the cylindrical protrusion from the center of the wheel, about the size of a can of tomatoes. I find them to be much easier to work on than semi-floating axles.

Semi-floating axles save weight and cost by getting rid of the outside roller bearing. The wheel is supported only by the axle shaft, which goes through a tapered roller bearing roughly even with the inside of the wheel, and then engages the gear in the differential. Unlike a full floating axle, the axle shaft is attached on the differential side using a c-clip or something similar. This provides the support to push the wheel in towards the vehicle that would normally be provided by the outside bearing in a full-floating setup.

Semi-floating axles are a weaker design because the weight of the vehicle puts stress on the axle shaft. It is for this reason that they are only used on cars and lighter trucks. They also do have the limitation that if you break an axle shaft, the wheel comes off. Full-floaters can be driven (using 4wd and getting power to front wheels only) with a broken axle shaft, or pulled. Semi-floating axles are harder to work on because you have to drain the diff and pull its cover off to get to the clip, in order to get to the wheel bearings.

My CJ-2a has a full floating front and a semi-floating rear, with a goofy setup where you grease the rear bearings through a zerk fitting. The excess grease comes out through a relief hole on the top of the axle tube. Weird.

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This Page Last Updated 18 September, 2000 [Hit Counter]