Differential carrier bearings

[SR20-620]

Hi Im new here. Had my 620 up on jack stands and had the engine running with the trans in gear, noticed my rear wheel was wobbly, all lug nuts are tight, tires are brand new and balanced, could my differential carrier bearings be worn out? I just changed the fluid in my diff like 50 miles ago. It was normal color and there weren't any metal shavings in it. I have never replaced the wheel bearings etc. as far as I knwo it is all factory. When you spin the rear wheels you can hear the gears coming in and out of contact in the diff, it sounds like they are meshing tighter then looser, tighter then looser, as the wheel turns around. I have been looking for one of the precision gear power brute units and have found some in russia and australia for around 1200$ I called precision gear and asked them what was up with them not making it anymore with a market for them out there, I told them that many people would be interested in one if they had a run. I am waiting for a call back.

[Z-train]

Wobbly wheel is either a bent axle or a bad wheel bearing...most likely.

[SR20-620]

I would say bad wheel bearing is more likely, how many have ever really had a bent axle on a vehicle that wasnt involved in a crash? if it did bent it would probably bend out at the hub right? the axle is firmly supported everywhere else.

[SR20-620]

what about the carrier noise the seems to be linked with the wobbly rotation of the wheel?

[datzenmike]

Swap the rims side to side and see if the problem moves. This will eliminate a bent one which is easy to fix. I guess an axle could be bent, but you would expect some damage to the rim and tire doing it.

 

Check the diff oil level. They usually don't go bad as long as they are full.

[SR20-620]

The oil level is spot on, I just had the hole unit out and cleaned/ painted it and installed a new pinion seal, I refilled it with gl-5 75-90w. I will swap rims and see what happens. What about the gear noise? If the wheel was bent it wouldnt cause the axle to move so much as to cause the gear noise.

[datzenmike]

Was it low before?

 

The noise could have been the wheel bearing.

[SR20-620]

yes it was a bit low before, some of it had leaked out of the pinion seal. I looked down inside of the housing when I was replacing the seal and I didn't notice anything out of the ordinary. I suppose that because it was low on oil it could have damaged it, but im not exactly sure how low it was. It still had fluid in it but not as much as i had to put back in it. How hard is it to remove the carrier? I have done it on chevy trucks before, but they had a diff cover. how do you get the axles out?

[datzenmike]

Drain the rear end.

Mark the drive shaft so it goes back on in the same position and remove

Remove the L&R hydraulic brake lines.

If removing the axle to replace the wheel bearing, disconnect the emergency brake cable on the crossmember. Otherwise it should stretch far enough to unspline from the diff.

Remove the 4 X 17mm bolts behind the backing plate.

Axle should pull outward from axle tube. You may need to Hammer on a block of wood to loosen them.

If just removing the differential you can pull the axles out about 6-8" to disconnect the side gear/axle spline. If you do, have something to support the weight so it does not dent the seals in the axle tube.

Remove the 10 or 12 nuts around the front of the diff and lift out forward. It weighs 70-80 lbs. so be ready for it.