Hi folks, I've been noticing a rubbing/grinding noise coming from the rear diff lately so I decided to have a look-see. I put it up on blocks, removed both wheels and diff cover. plenty of gear oil poured out at that time. Upon inspecting it, there isn't any noticeable problems I can see with my untrained eye. when i rotate the hub on either side I can hear the noise. it kinda sounds like a television that cant find a signal (static sound). It's a constant sound that increases pitch when spinning the hub faster. if i rotate wheels using the drive shaft (yolk i think its called) same noise. The noise sounds like it's coming from the front part of the diff just past the u-joint but inside the diff. there is a bit of chattering if i spin it slowly using the drive shaft but I think that can be attributed to the gear teeth touching as they come together during rotation. I should also mention that when I rotate the hub forward and backward slightly in either direction, the is a bit of play in there, creating a knocking sound when I switch directions of the rotation.

never messed with a rear diff before but based on reading other posts, it sounds like the pinion bearing and or the axle bearing might be going bad. can anyone who has had similar issues comment on what their fix was or provide insight on other tests I can run to isolate exactly where the problem is?

It's a bone-stock '96 1500 5.2L 2WD (Sport) with 94k on all origional parts. it's been an awesome truck with no problems up to this point.

Thanks in advance

 

Second the front pinion bearing. If you can feel it, it's bad.

 

Good time to upgrade!!!!

 

Hi there, just read your post from awhile back. Im having the same issue you described. I was wondering how you made out with that. Did it end up being the front pinion bearing? Did you do the job yourself? I'd love to hear how that worked out and any tips you may have. Thanks

 

Been a year, and he hasn't been back. Don't expect an answer. Your best bet is to drop the driveshaft, and wiggle stuff. See what moves, that shouldn't.

If that doesn't present anything, pull the cover, and have a look inside.