Adjusting Shift Points in 4L60 / 700R4 Trans
Thread Starter
Racer
Joined: Dec 2013
Posts: 419
Likes: 5
From: Bel Air Maryland
Adjusting Shift Points in 4L60 / 700R4 Trans
How would one go about changing the shift points in a stock GM 4L60 / 700R4 transmission in a 92 Corvette? I was told these transmissions were built by GM to shift at roughly 5500 to 5800 RPM, but since the trans is not controlled by the car's computer (as is the 4L60E models) the shift points cannot be easily changed. I'm running a 383 stroker with a high-profile cam and 3400 rpm converter, and need to find a way to wring higher RPMs from my motor since I'm probably leaving quite a bit of power on the table because of transmission. I imagine the engine is capable of spinning to around 6500 and producing some additional power, but the trans is holding it back. Please send help!!!
Thanks ..... Wheel Stander
Thanks ..... Wheel Stander
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
You need to adjust the weights and/or springs in the governor to change the shift points. I've never done it so I don't have any personal experience with this. I do know that B&M makes a governor modification kit that has alternate weights and springs.
Thread Starter
Racer
Joined: Dec 2013
Posts: 419
Likes: 5
From: Bel Air Maryland
Thanks, Cliff. I'll have my Corvette tech look into this for me.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
I bought 2 B&M kits and mixed and matched weights and springs. Lighter springs will give you higher wot shift points. The lower shift points are determined mainly by the springs, although the weights also play a part. I used a combination of stock weights and B&M weights and even ground some of the weights to get the exact weight I wanted. Trust me, you can spend a lot of time doing this trying to get the car to run perfectly on the street as well as the track. I got pretty close. Finally bought a 4l60e which I can controll all shift points with a laptop.
