rear end/diff problem
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Joined: Feb 2001
Posts: 79
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From: Pa
rear end/diff problem
Hi,
I have a 1992 C4, 6-speed. Here's the problem, I hope you can help. Last year I noticed that when I accelerated from a stop while making a left turn, that the rear end seemed to buck, or hop, jerking the car. I got off the gas, slipped into second and it was fine. It would happen once in a while at other times, almost always on a turn and while accelerating.
Got the car inspected last week, took it for a ride today and noticed the same thing only it was happening while pulling out from a stop. It feels like the bucking you get when you are pulling out in too high a gear. It alsmost feels like something is locking up, then letting go. When i got closer too home, I downshifted into second to test the car. While at about 2000 rpm's I got on it a bit, while going straight, and it did it again. So, it seems to do it under higher torque.
Three years ago, it only did it when accelerating hard while making a turn. It did it maybe twice a season. Now three years later, it is doing while going straight under higher torque conditions. It has ASR and I turned it off and it made no difference.
I've only put about 2500 miles on it since I've had it but I don't know when the differential fluid has been changed. I haven't changed it, though I do have some I ordered two years ago sitting in my garage (good plans, poor follow through)
I'd appreciate every bit of advice you can throw my way.
Thanks
Randy
I have a 1992 C4, 6-speed. Here's the problem, I hope you can help. Last year I noticed that when I accelerated from a stop while making a left turn, that the rear end seemed to buck, or hop, jerking the car. I got off the gas, slipped into second and it was fine. It would happen once in a while at other times, almost always on a turn and while accelerating.
Got the car inspected last week, took it for a ride today and noticed the same thing only it was happening while pulling out from a stop. It feels like the bucking you get when you are pulling out in too high a gear. It alsmost feels like something is locking up, then letting go. When i got closer too home, I downshifted into second to test the car. While at about 2000 rpm's I got on it a bit, while going straight, and it did it again. So, it seems to do it under higher torque.
Three years ago, it only did it when accelerating hard while making a turn. It did it maybe twice a season. Now three years later, it is doing while going straight under higher torque conditions. It has ASR and I turned it off and it made no difference.
I've only put about 2500 miles on it since I've had it but I don't know when the differential fluid has been changed. I haven't changed it, though I do have some I ordered two years ago sitting in my garage (good plans, poor follow through)
I'd appreciate every bit of advice you can throw my way.
Thanks
Randy
Le Mans Master
Joined: Oct 2004
Posts: 7,706
Likes: 485
From: Everett WA
C4 of Year Finalist (appearance mods) 2019
Go get the diff fluid changed & make SURE that they put the correct gm-additive in there. That is what's causing your problem. The gear oil usually doesn't wear out but it's the additive the helps prevent the clutch pack in the posi diff from binding during turns that wears out. SB changed every 25K. 
