Can I manually shift a C-4 without aftermarket valve body?

stock88

New Member
Jun 18, 2003
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upstate NY
I was wondering if I can shift a C-4 through the gears myself, or does it have to come with a special valve body for this to happen? I know the aod shift points are pre-determined on my car now, but how does putting in a C-4 change them?

Thanks for any advice.
 
C4s are really good trannys and fairly strong in stock form. I would recommend an aftermarket ratchet-type shifter, deeper pan, fluid cooler and a good convertor. They are also much lighter internally than the C6s.
 
stock88 said:
I was wondering if I can shift a C-4 through the gears myself, or does it have to come with a special valve body for this to happen? I know the aod shift points are pre-determined on my car now, but how does putting in a C-4 change them?

Thanks for any advice.


I think that it has some safetys built in. I dont think that it will go into first or second at high speed. I do know that if you short shift to second, it can downshift back to first if you give it too much throttle.

A manual valve body will be manual all the time, but it will shift fast and hard!
 
Thanks for the replies.

CHarris- Along with the Perf Auto C-4, I'm getting a tci converter, a deep pan from Perf Auto, and a Hurst quarter stick pistol grip shifter (I already have a B&M cooler). I was wondering about the shifting ease after I read an ad for a manual valve body for the C-4, but I thought you could just shift the 3 gears anyway. Why would anyone get a manual valve body for something they can already manually shift? As you can tell, I'm new to the tranny game. Hopefully I won't need to buy a valve body on top of this. I want to be able to hold 1st until 5000 rpm, then 2nd until 5000 rpm, and let 3rd go until the end (at the track).
 
First of all, the valve body determines your shifts. Not the car. An AOD shift is in an AOD valvebody and the same for a c4. A c4 because of its configuration can more easily be manually shifted. Something to note, some c4's (early ones I think) had a goofy shift pattern and could not be manually shifted so as to benifit you for racing. I can't remember the exact shift sequence. A manual valve body is usually just that, manual upshift and manual downshift or just manual upshift for racing. IE you set your own shift points, kinda like a manual transmission. Also these aftermarket valve bodies are recalibrated with differant "programming" via springs, valves, fluid passages etc. to give you much harder, positive, and non slipping type shifts. In most street driven applications, you could benifit from a simple, cheap, shift improver kit that lets you reprogram your existing valve body for about 50 bucks.