Having this problem on my v6 3.1 automatic. Was driving like normal and pull into a driveway , put it in reverse and as i hit the gas it just revved up and jumped back and I could hear the differential grinding . I had to rev it up high to reverse and was jerking back and differential was grinding bad. But drove fine in drive. Any suggestions help?. Seems like it's my rear.

 

Nope, it's your transmission. A rear end can not slip. It either works or it doesn't.

 

Pinion nut is loose, and pinion is getting sucked into the housing when in reverse (in drive it tends to push itself out) and rubbing on the outside of the carrier.

 

So is it my trans or differential....? I have a 84 z28 10 bolt rear... Would that swap into a 92 rs v6???I could swap in if its the differential or is it in easy fix?

 

Get under the car and see if you can move the yoke on the rear end up and down. If it doesn't move then take the transmission to a rebuild shop and get it fixed.

 

Just checked it and it doesn't move. So It's the trans then ��

 

Yea, take it to a transmission shop and have them verify it.

 

Pop the rear end cover off and look, before submitting your checkbook to THOSE people. $15 of fluid vs $1500 of transmission... whaddya got to loooooze?

 

You were right sofaking I have been ignoring my rearend . So I drained and filled with some fresh valvoline and problem went away with a few hours of driving. Hope it doesnt come back. For now I will take it easy on the 3.1

 

Were there pinion marks around the outside of the carrier?

Out of curiosity, what gears did it turn out to have?

 

It had stock gears and I'm not sure what the carrier is but the inner smaller gears looked very worn. Well the problem came back again were I couldn't reverse so I checked the trans oil and it was overfilled and bubbling..... thing is when I did the oil change on trans I remember getting the oil level right at the hot mark . So I drained some oil and I had reverse again. I think maybe I need a fan on my trans cooler ha.