Correct shifting on 1984

[Walter F.]

My 84 has option MXO Automotic transmission with overdrive which I believe is a THM 400. This transmission was rebuilt by the previous owner. At WOT the transmission does NOT shift hard into gear as I have noticed other THM 400 Corvette transmissions do. In fact some shift so hard they chirp the rear wheel in the up shift. What is the factory correct way the car should shift. Mine shifts like my 2014 malibu at WOT. It goes into gear smoothly. Is that correct?

[Walter G.]

Re: Correct shifting on 1984

I've owned my '84 since new and it has 25,000 miles. I had it out for some 'exercise' last weekend and despite the anemic 205 HP it will still chirp the tires on the 1-2 shift. Always has, which gave the illusion of power when I gave friends rides back in '83 when I got it.

[William C.]

Re: Correct shifting on 1984

I believe it is a 700-4R trans. The turbohydro was three speeds only

[Joe L.]

Re: Correct shifting on 1984

I believe it is a 700-4R trans. The turbohydro was three speeds only

Bill and Walter----


Yup, that's how it is. The automatic transmission used for all C4 Corvettes was the THM-700-4R. The THM-400 was last used for 1977 Corvettes.

[Walter F.]

Re: Correct shifting on 1984

So is it safe to say from 1977 on the THM-700- 4R should shift hard at WOT? If that is true what would be causing my 84s rebuilt to shift differently?

[Joe L.]

Re: Correct shifting on 1984

So is it safe to say from 1977 on the THM-700- 4R should shift hard at WOT? If that is true what would be causing my 84s rebuilt to shift differently?

Walter-------


I can't speak to the shifting feel. However, the THM-700-4R was first used in Corvettes for the 1982 model year. 1978-81 used the THM-350.

[Mike E.]

Re: Correct shifting on 1984

I bought an 1984 AT brand new...Long gone now, but it would shift in to OT at very low speed if you were easy on the throttle. This made it achieve some pretty impressive fuel economy. Unfortunately in 1984 when gas was less than a $1/gallon it really didn't matter too much to a 28 year old. The local Corvette Club used to have economy runs. It was basically a rally when you tried to use the least fuel possibly. I'm pretty sure I took first place in that event. On smooth pavement though the handling of the car was truly world class, probably the best corning production car of the time.

Mike