Diff needs new bearings

[chase_mull3r]

Okay I'm sure this has been covered somewhere but I can't find anything. I have a welded 4.10 differential and the right bearing seized up on me completely. What will be needed to put new bearings in it? I already took it out

[TobyB]

The hardest part is getting the races and cones off- you need a puller that can get on the
lip, and that's not easy. Or cut them off- that always makes me nervous, so go carefully.

Then a press to put the new ones in.

It's been a long time since I did a mid- case- I forget the details- or rather, I'm afraid I'm
mixing up generations of diff.

Take it apart. Keep the spacers in their original locations, and you should be able to figure it out.

t

[ForcedFirebird]

I agree with Toby, not overly difficult. I use the press for the whole process, just have appropriate sized round slugs to fit the races. The outputs are much simpler than the input.

[nrubenstein]

Here's my question: If a bearing has "seized completely," how likely is it that the diff is comprehensively fucked? That seems like something that results in collateral damage.

[ForcedFirebird]

Here's my question: If a bearing has "seized completely," how likely is it that the diff is comprehensively fucked? That seems like something that results in collateral damage.

Yeah, usually they are without fluid when I see them seize.

[e30davie]

What kind of ugly noises was it making for the 100 miles before it seized?

[TobyB]

Yeah, I agree, if the bearings died a natural (or unnatural) death, the gearset shouldn't look so good.

But if by some miracle, the gears were aligned mostly correctly and the bearing preload
was too high, that'd kill the sidecase bearings and not hurt the gears.

I've revived a few "dead" diffs that had the pinion crush sleeve overcompressed-
the bearings die quickly and noisily, but usually everything else is ok.

t

[jeffnhiscars]

When I hear the words bearing and welded in the same sentence I'm reminded of having some welding done in a shipyard. I was told that if you don't put the ground right near where you are welding you are very likely to arc your bearings leading to a drastically shortened life.

[chase_mull3r]

It was only used on a track. I drift my e30 and when I took it out their was almost no fluid in it. I'm looking in to getting a new pinion and gear as well. I found a 4.10 gear ratio for sale I was going to pick up

[nrubenstein]

It was only used on a track. I drift my e30 and when I took it out their was almost no fluid in it. I'm looking in to getting a new pinion and gear as well. I found a 4.10 gear ratio for sale I was going to pick up

Ah, yeah. Just trash it.