ps374

I have read and seen some videos of C4s shifting and chirping the rear wheels at WOT. This brings me to my question about Corvettes with option MD8 700R4 automatic transmission. This is the tranmission in my early C4. Is my transmission supposed to shift hard in gear at WOT or should it shift like a basic Chevrolet sedan transmission? What is considered normal shifting in a STOCK factory Corvette transmission? Should it bang in gear at WOT or shift the same as in nornal driving?

gerardvg

The Turbo700R4 is the best of both worlds, the TV cable controls line pressure and shift points. So nice smooth shifts when dawdling around town at low speeds with minimal throttle application, however floor it and she becomes an animal hard shifts high up the rpm band lighting the tires (With 3.07 rear gears). I have some great video of my vette, smoking the tires during the 1-2 upshift sliding the car sideways. Try adjusting the TV cable so at full throttle travel there is no deflection, it may just be that the trans is becoming tired and the clutches have had their best days.
What diff ratio do you have? the 3.07 was an option (most got the 2.75)

Capn

My 84 shifts like any other car when cruising, at wot it shifts solid from 1-2 but I wouldn't call it hard. probably tired tho. But 2-3 shift at wot feels like a mule kick'n my rear lol.

N42375

My 90 coupe will shift so smoothly around town that you have to watch the tach drop to actually know that it shifted. But put your foot down hard and the tires will break loose and chirp on the up shift. Scared the hell out of me the first time the rear end side stepped out!!!

ps374

My build sheet says HE3 307 ratio which I thought was standard on 6 speed????

65Z01

My prior '88 would NOT chirp the tires in stock form but with a shift kit and shift points raised to 5,800RPM it would wag its tail at 1/2-3/4 throttle upshift...

ps374

Whats puzzling to me is the last owner had this transmission rebuilt about 30,000 miles ago and he told me he had a shift kit installed. He also had synthetic oil put in the transmission when it was rebuilt. I checked the TV cable and it is at it max adjustment and the cable is tight at WOT when the car is off and the engine is cold. Is there anyway these trasmissions can be adjusted internally by a transmission shop?

gerardvg

You are lucky as it was a performance option the original buyer ordered, the base C4 has highway gears great for fuel economy not for performance. You can only fit a shift kit with the trans in the car.