Trying to make sure I get the preload right on my 1976 M880 (3/4 ton 4x4). Can someone explain
1) How to check preload
2) How to assemble onto hub. Can't I drive the bearing on with a punch? Been told it has to be a press.

I posted below (M880 wheel bearing/diff problems)
but didn't get the info so trying again.
Any advise about the diff and seals (questions in prior post) would also be appreciated.

I once had the same front axel, I swaped it for a chevy d44. If i remember that stupid set up its a pain in the ass. :shaking: on mine the front wheel had excessive slop, you could move the wheel from top to bottom. When you tighten the nut on the axel shaft nothing happens to the bearing pre-load. I made new shims for behind the bearing using a leathe. i also turned the spindle down so i wouldn't have to press the bearing on and off. If you dont have the equipment to do this then im not sure how to set the pre-load. I thought that you might be able to buy shims for the dealersihp to to properly set up the bearings. My advice would be to find a early chevy 3/4 ton and swap the axels out. its a bolt in with no fab work.best of luck and i hope this helps feel free to P.M. me with any questions

Thanks for the input. Mine also has the slop. Sounds like there may not be a simple solution. I'm sure I could come up with a shim if needed but I have a feeling it may need the retainer turned down to increase preload. Not sure yet as I haven't yet tried to check the preload.
Still not sure how to check preload! Maybe it's OK and slop is due to worn bearings? I think I just assemble the new bearings, spacers, and retainer onto knuckle and check for .006 gap between retainer and knuckle? :confused:

Im not real sure how to check preload on that either. my idea was if theirs no slop, and the wheel spins normal, then their most likely close enough to work

Im not real sure how to check preload on that either. my idea was if theirs no slop, and the wheel spins normal, then their most likely close enough to work
That's the way I did it! Just found out the knuckle is shot, slop in the balljoint mount! :mad3:
F%^&ng Dodge - time to get a new front end, and "free" D60's out there?

I'm surprised with all the folks wrenching on these things that a bunch don't have this fix down cold. I've been too busy to fiddle with it but will soon. I'll post the results.

Well here's the follow up.
With my races, and spacer in place the retainer bottomed out, everything snug, zero preload gap, supposed to be .006" between retainer and knuckle. So I had a friend with a lathe (the good kind of friend) turn down the retainer by .010". This was a guess at what would be required. I did not wish to remove the knuckle to allow measurements at the lathe.
Reassembly gave .008". Close enough for me. I doubt .002" extra preload will hurt anything. The wheel seems to spin well enough. I guess time will tell.
Here's a little trick I figured out for putting the outer bearing onto the shaft without a press. Cut through the inner ring of the old outer bearing with a cutting torch and clean up the inner diameter with a file. Use it to drive the new bearing on without damaging it. The cut allows it to slide back off the shaft easily.
Hope this helps someone.
Arlie