The Stovebolt Site Forums The Parking Lot Big Bolts Rear bearing packing/preload for a '48 2-ton

I am just finishing up doing the brakes, and I was wondering if someone has the specs on bearing preload. My truck is a 1948 6400 with a two-speed rear if that makes any difference. If no one knows, I'll just return it to approximately the same position.

The manual says 60 foot lb preload.

Hope you understand "Preload" is just that, a temp tightening, then let it off, lock in diff way. On your truck, get one of those big tin sockets to fit your nut. Snug the middle one while turning hub/wheel to about 40 lbs. Then back it off about 1 flat on the nut. It will seem loose. Then put on the locking tab ring with tab in axle and maybe into slot in nut if it was that way before. Don't be afraid to turn nut some looser if needed to line up notch. The second or outer nut is the ONE that needs the torque on it. I just looked in manual and it says back off inner nut 45 degrees from tork. The outer one just says to tighten fully, didn't give torque reading in print or specs. Think you can go pretty high like 80lbs or more. Then bend over a tab on washer into a slot on nut to lock.
If you have nuts that are not hex, there is a special socket for them. I got one, was $70, but fits many years of trucks. Otherwise you are guessing with hammer and punch or big pliers. Most important to make outer nut tight and locked, or both will work there way off and wheel/hub and axle will roll out of truck on a corner or elsewhere.
I see on another post about burning off oil on shoes. That was new to me. I get mine relined, usually $25 to $40 depending on size at a local brake parts shop. I once tried brakleen on some, looked good as new. Once installed, oil bled up from inside farther, and brakes grabbed bad again. I would bet that is what you will get too. Once oiled up, they are ruined. Get new seals too, usually can find them at brake shop or parts houses fairly easy.

Some of these full-floating bearings are oiled by the gear lube from the center housing, while others need to be packed or pre-oiled until lube can migrate down the axle tubes. I've seen new bearings fail because they were assembled dry. I generally try to pack rear hub bearings with multi-purpose grease, not wheel bearing lube, on assembly, and let the differential lube migrate down the tubes and dilute the grease during normal running. Preload needs to be a firm tightening to align bearing cones and cups, then enough loosening to allow the lube to work its way into the bearings. The outer nut needs to be TIGHT to keep the inner nut adjustment correct. I like to get the inner nut as tight as I can without really honking down on the nut, then loosening about 1/4 turn or less, until a lock washer tab aligns, then really sock down on the outer nut, and bend the lock tab to secure it. If there's any issue with the integrity of the tabs on the lock washer, replace it!
Jerry

I got the bearing preload set pretty close, the senior mechanic where I work does a lot of trucks, he said preload to 50, back it off to no load, and then load to 30 and leave it. This was only like one flat, possibly 45deg. This works fine with no drag, we'll see. The outside nut is not the issue, I know it needs to be tight/locked in. It won't work loose. Burning the pads is a trick I learned from an old-timer, he did it for years and years with no problem, although many people have said it causes problems. Brake cleaner wouldn't do the trick since the pads are porous and hold the oil in pores. We'll see. The problem I have now is that the return spring is broken on one side and I can't seem to get a replacement anywhere. If anyone knows where I can get one, it would be great. Last resort I can have one custom-made.

You'll wind up replacing the brake linings after a few stops. No matter how clean they look, more oil will seep up to the surface once the normal heat of brake operation develops. I've tried every solvent known to man, heat, etc., and I've never been able to rehab oil-soaked brakes!
Jerry

I've got some BIG springs from my Tilt-cab or little ones from front. Too big, too small.

I see you have early jeep. I'm looking at a 57 and know nuttin' about jeeps. Think this is an F-head engine, not sure. Says CJ-5 on tailgate, but some say should be CJ3B or such? More rounded type fenders, not so flat. Where is good web-site to talk jeeps and see models, etc. I searched for a few, most not to informative, found one good one in bunch. Name? Forget now! Fella want's $500 for this rusty, ran when they parked it with tin top unit. Pretty dang rough, not much orig on it. Needs brakes too, probly MC for sure, or all of it. I could get for less, but not sure I want to. Some fellas on sites say "Buy it", sounds cheap, others say beware, money pit. Seems like plenty of parts to be had for them.

An old timer once told me that dropping brake shoes in boiling water for a few hours would remove all grease and oil. He swore by it, but I never tried it.