1981 Corvette Torque Converter Replacement
Thread Starter
Instructor
Joined: Jan 2022
Posts: 144
Likes: 15
From: Texas
1981 Corvette Torque Converter Replacement
Hi again everyone, I tried to do some research but thought I should get a final opinion here. My torque converter seal is leaking bad and my mechanic friend who owns a shop offered to show me how to drop the transmission and do it for free. I figured since the seal is leaking I might as well just replace the torque converter (and any relevant parts that you guys suggest while its dropped) the problem is; I'm not sure which TC to put in there. I think I have a stock TH350C (not 100% but its automatic, and it should be the original trans and engine) but I don't know anything about the cam, its probably stock. I work at an auto parts store so I have access to a few part numbers from B&M for the Holeshot Nitrous line and was looking at the stall speed of 2300-2500 from PN# 20480 would be a safe and good upgrade, (but it says its only for the TH350 so I'm not entirely sure.) After that's all said and done, I feel like my old TC is just showing signs of old age and not performing well, so if none of the "upgrade" ones would fit I could always get a stock one but I'm looking for opinions first.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
I don't know if you are running the computer but if you are not,
you can get a standard TQ verter non lock up.
also if motor has performance parts, you can get a different rpm flash point to
match where engine makes power.
you can get a standard TQ verter non lock up.
also if motor has performance parts, you can get a different rpm flash point to
match where engine makes power.
Race Director
Joined: Mar 2017
Posts: 11,931
Likes: 4,497
From: Virginia
Wait, you have a friend who will drop a transmission for you for free?
What if the transmission that came out of your car isn't the same one that went back in? What if instead of a TC, you looked for clutch suggestions?
What if the transmission that came out of your car isn't the same one that went back in? What if instead of a TC, you looked for clutch suggestions?
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
I would also look at changing the bushing in the front pump. If the seal is leaking there is a good change the bushing is the root cause. Unfortunatly, the easy way to change that bushing also involves remoing the front pump from the trans.
Thread Starter
Instructor
Joined: Jan 2022
Posts: 144
Likes: 15
From: Texas
Sorry my transmission knowledge is actually quite low compared to the loads of other information I know about this car. I have the computer plugged in but its doing more harm than good so I'll probably just disconnect it since I added it for testing purposes. I'm not familiar with a lock up converter so I'm not quite sure what the purpose or pros of that is compared to a regular TC.
Thread Starter
Instructor
Joined: Jan 2022
Posts: 144
Likes: 15
From: Texas
Yes, I've met a lot of mechanics and shops at my job and he offered to drop it for me and show me how to do it at his maintenance shop. It should still be the original transmission, to my knowledge its never been removed from the vehicle.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
computer system has a computer controlled;
carb
distrib
trans TQ lockup.
plus smog devices.
so, to remove comp requires;
new, used,
non comp carb
non comp distrib
your friend should know about trans lockup
carb
distrib
trans TQ lockup.
plus smog devices.
so, to remove comp requires;
new, used,
non comp carb
non comp distrib
your friend should know about trans lockup
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Thread Starter
Instructor
Joined: Jan 2022
Posts: 144
Likes: 15
From: Texas
I replaced those a while ago, I have a 1980 Quadrajet non-electronic 4 bbl and a HEI distributor as well. Most of the smog devices have been removed or at the very least aren't even functional anymore.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
then discuss lockup and TQ stall rpms with your trans guy.
