I bought a reman. C6 trans awhile back and installed it myself. The thing will not take off in 1st gear if its in drive but it will take off in 1st from first gear. I have to manually shift it from first to drive but it shifts fine from 2nd to 3rd. Is there something I can check or do myself. I'd rather shift manually than pay the price for a tranny shop to fix it so any help is appreciated. Thanks.

 

The easiest thing to check yourself is to make sure you are actually in Drive and not second at the transmission when you are in Drive at the gear selector on the column. Hopefully, when you installed the tranny you didn't adjust the linkage correctly. I say hopefully because this is an easy fix. You didn't say what year your truck is but the fix is basically the same for most of them. Disconnect your shift rod from the tranny lever on the transmission and have a friend hold the shift lever on the column in Drive. Pull the tranny lever on the Transmission all the way toward the back of the truck and that is first gear. Push it two clicks forward and that is Drive. swing the shift rod back to the hole in the tranny lever and if they don't line up you'll see a threaded end with a locking nut on either end of the shift rod.(different years are either at the top or the bottom of the rod). Loosen the nut and twist the rod in the direction you need to go. You might have to repeat this a time or two to get your column lever lined up with your PRND21 indicators. If this ain't your problem maybe somebody else has an idea better than going back to the tranny shop. Good Luck!

Chuck
'71 F-250 390 C-6

 

Yeah, I had hoped that was it too. But I wasnt that lucky. Thanks for the reply.

 

my c6 hasn't been reman., as far as i know, and it does the same thing. it also takes a long moment to go into reverse. it doesn't down shift unless i come to full or almost full stop. i have to do it manually.
i plan to reman. this c6 in the spring, myself. let us know what you find is wrong with it.

 

Mine does the exact same thing. It doesnt really bother me to have to shift it like that but I would like to know why it doesnt work correctly. If I find out anything Ill be sure to post it.

 

I adjusted the linkage today but that didnt help, anybody else want to take a stab at it? Thanks for the suggestion on the linkage.

 

It sounds like your transmision governer might be sticking. Im pretty sure it is what is controlling your down shift. Your vacuum modual controls the up shift timing. Get your self a haynes trans manual. I rebuild my c-6 with it as a ref. I am very pleased. My trans is remanufactured now not rebuilt. If you have a 2 wheel drive you shoud be able to r and r your governer, after you take off the tail piece.
I would also pull my valve body. replace the filter, dissassemble the valve boby. clean it then put it back together. The valve body can be done in 2 or 3 hours. with no special tools at all. But get the book. Also get the inline filter available from raybestos. To keep all the trash out of your fluid.

 

I've had several different breeds of trannys that did not shift into 1st at a stop if I took off easy, but if I stepped into it I could feel it downshift to 1st and take off. I always figured this idiosyncracy kind of went with the territory of driving juice boxes.

Trail Rider