Tranny question
Thread Starter
Pro
Joined: Apr 2006
Posts: 647
Likes: 22
From: Norwalk CT and Boynton Beach FL
Tranny question
I have a 75 L-82 Auto. This car is all stock and I haven't used the car much in many years and I'm just now trying to fix a lot of odds and ends and start enjoying the car more. I had the tranny rebuilt in 1996 (didn't really need it but I got talked into it). Ever since the rebuild I've had the following issue with the tranny. When the engine is cold and all fluids are cold, when I put the car into drive or reverse the car shifts smoothly into gear. However, when the engine is hot and all fluids are hot, when I put the car in drive or reverse from neutral (idle 700 rpm) it goes into gear with a jerk. Tranny fluid is full. Any idea why I this would happen and what the fix would be?
Thanks
Thanks
1st Gear
Joined: Mar 2007
Posts: 1
Likes: 0
Me too
I have the same problem, only it makes no difference whether its warm or cold. I haven't been able to figure this out yet. I've replaced the filter, fluid, vacume canister and U-Joints. Still doing it. It's worse going into reverse.
I'm planing to have a look at the trans mount and
check vacum lines. I hope it's not my rear-end!
My car is a 77 L-82 with a Th-400
I'm planing to have a look at the trans mount and
check vacum lines. I hope it's not my rear-end!
My car is a 77 L-82 with a Th-400
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
look at the front mounting pad for the differential ..this is the clunk when you put it in to gear....and is more noticeable in reverse
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Did the vacuum modulator get changed out with the rebuild? If so, and the rebuilder used a "gypo" knock-off replacement, you might end up with the problem you have. Find out what brand / model vacuum modulator you have. If not the same as original, or a direct replacement, you might want to change it out. Also, if you had any work done on the valve body...shift kit, modifications, etc.....you might end up with the same problem. Lots of rebuilders use little "tricks" to get firmer shifts; but they might tamper with the shift timing to get what they want done.
Le Mans Master
Joined: Jan 2007
Posts: 8,007
Likes: 3,341
From: Omaha NE
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2022 C3 of the Year Finalist - Unmodified
2020 C3 of the Year Finalist - Unmodified
When mine went bad it did this. Also made a thunk if I let off the gas quick.......
