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I want to change my C6 trans module. There are two units for 1980. They go by the color stipes. What is the difference in the two?
I have the Haynes manual but it does not mention the module or color codes.
How do I know which color module to get? I have a February 1980 build date on the truck.
My present module does not have a visible color stripe to refer to.
One code is BLACK, BROWN or PURPLE. The other is GREEN or BLACK.
My problem is the transmission will NOT upshift after I kick in the passing gear at low speed. If I kick it down at a higher gear/speed it will shift up (most times).
The trans shifts at proper speeds while driving at "normal" speeds.
I checked the vacuum lines and they appear uncracked and functioning propery. I THOUGHT A MODULE CHANGE MIGHT BE THE SOLUTION.
Make sure your kick down linkage is working properly. My c6 had a large yellow tube rod going from the carb down to the tranny. It should have a spring that pulls it back reliably if you lift up on the gas pedal.
This and the governor in the tranny mainly have control during wide open throttle maneuvers, since you have little vacuum with the carb throttle wide open.
I agree. If the tranny shifts OK under normal conditions then the module is not the problem. Many of the modules can be adjusted by turning the screw in side where the vacuum hose connects.
Franklin & kermmy. Thanks for the help.
OK. I'll "*** U ME " that the module is working but, for my own benefit (and anyone that reads this), what about the color coded modules? IS there a difference?
I DID adjust my kickdown linkage because it wouldn't downshift at all when I first got the truck last year. I also adjusted my mid-band this winter.
So now what other adjustment might I be looking to accomplish? Why would it NOT complete the upshift?
I am thinking just because it DOES downshift is that the only adjustment there is?
I know the modulators are color coded, because I replaced mine, and I could barely see the strip on it. But I could make it out, and I got the right one. I don't know the difference, sorry.
I would go out under the hood, and push the kick down arm back, and let go of it, and see if it comes back to home with some authority. Also make sure there is plenty of clearance around it. You never know, one of your motor mounts may be broken, and when you get down on it, then engine twists up and puts the linkage in a bind against something. If you want to check that, hold on the brake, and with the truck in drive, push on the gas and see if the engine raises up(takes two people).
Franklin, I went out and rechecked and readjusted my kickdown linkage. It was about 3/4 in. off. The carb throttle linkage was strinking the kickdown "plunger" too soon. So much for my initial adjustment. I turned it back with the proper (.060) gap and..."so far, so good".
IT'S ALWAYS THE LITTLE THINGS!!! Thanks to all that replied.