94 z28(auto),reverse is feeling grabby. like stutters when in reverse gear. buddy had similar problem says to change diff fluid before thinking tranny issues because first and 2nd in drive still pull great. want to change fluid but is my rear a "standard diff" or limited slip?? how can i tell?? friend is great mechanic,he recommends just topping it off if its low, what do you think, complete change or just top off? says clutches in rear can get grabby if fluid is low. service manual says if changing all together and i have "limited slip diff" to add the "limited slip diff additive". thats why i NEED to know what diff my Z actually is. trying to hope for the best with a fluid top off or change and really need some GOOD advice. thank you very much, tight budget ,kids and it being the daily driver calls for all the hope and cheapest fixes for now!!

 

If I remember right the open diffs only came on the v6's. Also you might want to put this in the drive train section. You might get more help there.

 

Check your RPO tag for G80. That would indicate a limited slip differential. I think they are in the glove box or inside the door. I recommend changing it, just to be safe.

 

All V8 4th Gens left the factory with a limited slip differential.

 

IMO you and your freind are not on the same wavelength. The symptoms your friend describes would be noticeable when going around a turn, more so in forward than reverse because that is when you would have the most "differentiation" taking place in the rear end. When I say differentiation I mean the tires are rotating at different speeds and therefore the clutches will slip in the limited slip. You tires may churp while taking a turn if the clutches do not smoothly engage and disengage in the axle. Fixes include fluid level and adding more limited slip additive. However this does not seem to relate to the symptoms you describe. I would have your buddy go for a ride with you to make sure you are on the same page.

 

I had the same problem in my 2000 z28. It was a bad pressure plate on the clutch. It got so bad that it would "jump" the tires, i just stopped using reverse until replaced the clutch set.

 

In many cases, the 1993 - 1995 4L60E's had a problem with reverse when they started to get quite a few miles on them. 1996 and up 4L60E transmissions rarely had this problem.