Sooo....I'm learning and screwing things up at the same time...C'est la vie, right? Point of note....there are no inside axle seals inside the differential. I thought there were seals that can be changed so I took out the differential gears. BIG MISTAKE....Now I gotta buy the tool to adjust the inside bearings. I needed 8 hands to hold the differential in, hold the bearing covers, hold the screw adjusters and screw in the bearing caps...what a pain, and I'm still not sure that those screw adjusters are seated perfectly.

Anyway, besides venting about the above, have a question on repair bearings. I think Ralph had suggested using repair bearings instead of just replacing the outer bearings and seals. So using Rock Auto I bought them. Went today to put them in, and they don't seem to go all the way in flush with the axle. Are they supposed too? Attached is the original bearing and a replacement seal to give you an idea of thickness, and the new replacement bearing/seal combo. And a picture of one I've pounded in and that's as far as it seems to want to go.

Did I get the wrong repair bearings? Am I not pounding hard enough? Help please.

 

They're supposed to stick out a small bit - that's the secret, they ride where no bearing or seal has ever ridden before.

And that's how you avoid buying a new axle and/or housing due to miles on an old axle.

RwP

 

Thanks Ralph....I read a bit and see that's the case. I also read where it's a pain in the **** to get the clips in because of that extra little bit. Fun and games.

Any hints on how to properly get the diff assembly back in with the screw adjusters all square and not cross threaded to the bearing caps? I've got the caps a bit loose for now until I get that tool because I'm afraid of cross threading them.

 

The screw adjusters? Nope, haven't a clue, since my knowledge is mostly from reading and studying at this point (yes, I have the repair units for my truck; no, I haven't put them in yet.)

RwP

 

I've read through the manual several times and read writeups on line and it's still clear as mud. I get in theory what I'm supposed to do but the writeups use terminology like I've been doing this forever. What confuses me is how you center or position the ring gear using the screw adjustments which also simultaneously pushes the ring carrier back against the pinion gear due to the carrier bearings having a concave design. It talks about measuring backlash with a dial micrometer. I know how to use one but how is backlash affected by moving the ring gear side to side? I would guess more mating with the pinion but since the ring also moves back towards the pinion how do you know that backlash is decreasing because of side to side movement of the ring gear vs moving back into the pinion.

 

I've never attempted to adjust the rear gears, can't help you there buddy.

As for the repair bearings, they do stick out a bit but in my case they didn't make it any harder to get the C-clips back in place. Also, I was surprised to see that the repair bearing had 2 seals, one on the inside and one on the outside. Knowing that the original bearings were lubricated by the gear oil, I was concerned by this because the inner seal effectively locks out the gear lube. I contacted Timken and spoke with a technician who told me that the reason for the two seals is to provide longer service life. He told me that Timken's research found that the metal from diff gear wear is a problem. Apparently there is so much metal floating around in the lube, especially on older trucks, that it shortens the life of the bearings. For this reason the repair bearings come pre-greased and are purposely sealed off from the gear lube.