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valleyguy
05-20-2015, 12:31 PM
My truck has a leaking rear axle seal which ruined my brake shoes on that side. Here's a pic with the brakes and backing plate/shims removed. All I see is the bearing. The manual is not clear where the seal is located, and it just shows a cork seal thing; could use some help as to where the seal is located and .. how do I get to it.

http://i919.photobucket.com/albums/ad31/jadiggle1/DSCN1455.jpg (http://s919.photobucket.com/user/jadiggle1/media/DSCN1455.jpg.html)

gordr
05-20-2015, 12:59 PM
The seal is behind the bearing, in a recess in the end of the axle tube. The rear wheel bearing is lubricated by wheel bearing grease packed into it at the time of assembly, and not by rear axle lube, as is the case on many Brand X. Place the drum back loosely on the taper, screw the nut on a few turns, and use the drum as a slide hammer to withdraw the axle. That will knock the outer race of the bearing out of the axle tube. This method has always worked for me. Once the axle is out, the seal is plainly visible, and can be removed with a hook attachment on a regular slide hammer. Your local bearing/seal supply house should be able to match the seal, but our many Studebaker vendors will also have it. Wash and examine the bearing, and replace it, too, if it is less than perfect. Replace the seal, pack the bearing (new or cleaned) by hand with wheel bearing grease, and reinstall it. The end play spec is .002 to .006 inch, if remember right, verify in your shop manual.

Note: if the truck has Twin Traction, the right side thrust block will probably fall out of the center of the differential, and remain lying in the axle tube, which will foil your attempt to reinstall the axle. Get a strong flashlight, and use it to peer inside the axle tube. You will be able to see if that has happened. The tried and true fix is to fish out the stray thrust block with a magnet, then pass a piece of stiff wire through a straight piece of tubing. Kink or flatten the end of the wire so that it wedges a little when forced into the central hole provided in the thrust block. With the aid of a light, move the tube-wire-thrust block combo as a unit, and stab the stem of the thrust block into the hole in the differential center section. Then push in firmly on the tubing, and withdraw the wire. Once that is done, withdraw the tubing, and the thrust block will remain in place. Again, this procedure is needed only for trucks with Twin Traction. But you might have a Twin Traction axle in there, and not know it, if you don't know the whole history of the truck.

valleyguy
05-20-2015, 01:10 PM
Gord, I can pull the axle without going into the differential? Just slides out?


Joe

gordr
05-20-2015, 01:15 PM
That's right. No need to go in there at all. No C-clips, like the wretched Chevys! One thing you might do: pull the filler plug, and look in the filler hole. If you see a machined housing behind the filler plug, real close to the hole, close enough to touch with your pinky finger, then the axle is Twin Traction, and you can expect to have to deal with the thrust block issue. But if all you see is a cast carrier, deep inside the hole, then have a conventional axle, and no thrust block issue.

valleyguy
05-20-2015, 01:43 PM
Thank you; much appreciated.

Joe

valleyguy
05-20-2015, 02:25 PM
Gord, one more thing: I pulled that fill plug and there is an obstruction - kind of toward the right side of the pumpkin which I can touch easily, hard to see what it is. I also tried turning the drivers sided drum, and the other side turned in the opposite direction; is this a clue that is is NOT TT or is the visual think more accurate; I could pull the cover to get a closer look..

Thanks,

Joe

gordr
05-20-2015, 11:10 PM
The TT carrier is basically a cylindrical drum with a lathe-turned outer surface, and it comes very close to the back of the fill plug hole. Close enough, in fact, that if the fill plug is overtightened, it may contact the carrier and cause a mysterious noise. The standard carrier has a rough forged/cast surface, and is much smaller, hard, if not impossible to reach with a finger jammed in the filler hole.

I don't think you can rely on the "axles turn together / axles turn opposite" test to be definitive. Twin Traction could be present, but the clutches may may not be gripping. A large metal tag under one of the cover bolts that says "45C" or something similar is indicative of a Twin Traction axle.

valleyguy
05-21-2015, 07:42 AM
Thanks again Gord

JoeHall
05-21-2015, 08:43 AM
The rear axle "seal" is not really a seal, but more like a dust shield. If the oil level is filled to the lower edge of the fill hole, and you ever park sideways on a steep hill for more than a few hours, the oil will leak past the seal and into the back plate. If the drain hole is clear, at worst it will drip on the back side of the tire. If the drain is clogged, oil will surface inside the back plate and usually soak the brake shoes. I keep the oil level about 1/2" below the fill hole, and avoid parking sideways on hillsides.

valleyguy
05-21-2015, 02:01 PM
Thanks Joe. Good information!

jackb
05-21-2015, 11:15 PM
The rear axle "inner" seal is placed and constructed so that the R/A lube (oil) will not get past it to the backing plate. That is, unless its been subjected to wear, damage or some other very unusual conditions. You should be able to park all day long, at any angle/level without any oil getting past to the brake linings if installed correctly without damage. The old seals were felt, new ones neoprene. The outer seals are more of the dust-type to keep external stuff out....dirt, dust, brake dust etc...

JoeHall
05-23-2015, 08:49 AM
The rear axle "inner" seal is placed and constructed so that the R/A lube (oil) will not get past it to the backing plate. That is, unless its been subjected to wear, damage or some other very unusual conditions. You should be able to park all day long, at any angle/level without any oil getting past to the brake linings if installed correctly without damage. The old seals were felt, new ones neoprene. The outer seals are more of the dust-type to keep external stuff out....dirt, dust, brake dust etc...

I agree it "should" not be a problem, in that, it should have been designed better. However in the real world, it will leak as described. But this is not a mystery. To understand how it happens, remove an axle, and note the inner "seal" is located far inward, where the axle is not machined, and has a rough surface. If it were a true seal, it would chew itself up in no time, scraping the rough axle surface. Instead, the felt just lightly touches the rough surface, so consequently oil flows easily by it. I would be leery of installing a modern rubber seal that actually compressed on that rough axle surface, unless the car/truck was to be a TQ only. This problem can be avoided by keeping the drain hole open. But if the Stude is actually driven 20,000-30,000 miles between greasing, the drain hole tends to plug up with dirt & grease.

Even with the drain hole open, the oil will also trickle down the axle shaft and get on the bearing, and even seep into the tapered area of the axle where it mates to the hub. Again, I agree this should not be so, but it is real world experience. Best way to avoid this problem is to keep the oil level a little low, as mentioned above, and avoid parking sideways on steep hills, for prolonged periods.

As for the OP, are you SURE the brake shoes were not soaked with brake fluid from a seeping.leaking wheel cylinder? Whether brake fluid or oil, it usually does not get directly on the shoe liner. Rather, it gets into the bottom of the hub, when spins onto the shoe when the wheel starts to turn.

valleyguy
05-24-2015, 11:25 AM
Thanks Joe, Not sure what got to the shoes, probably brake fluid from my leaking wheel cylinder.. I just happened to notice oil at the bottom of the backing plate so assumed the axle seal was leaking as well. I did get a kit to repair the wheel cylinder, and that is now done. Looking for a inner seal now, (maybe don't need it based on your comments!): I did get that felt insert for the outer rear seal from S.I. (not sure what that will accomplish though).

Joe Diggle