C4 Shift kit factory setting recommendation

[Stock Farm]

Hi all - I have a 76 with a C4 and it shifts really hard form 1st to second (it was rebuilt last year) - My guess is that someone put in shift kit at some point in it’s life.

My question, where can I buy a ‘factory shift kit’?

Would like to bring this back to stage 0 as the factory had it and if it still shifts hard...not much more I can do.

Thanks
S

 

[Slowleak]

Hi all - I have a 76 with a C4 and it shifts really hard form 1st to second (it was rebuilt last year) - My guess is that someone put in shift kit at some point in it’s life.

My question, where can I buy a ‘factory shift kit’?

Would like to bring this back to stage 0 as the factory had it and if it still shifts hard...not much more I can do.

Thanks
S

I had that issue once. Best thing to do is pull the valve body and see what was changed. Even if the separator plate was drilled, you may be able to get it back very close to normal.

It may have some holes enlarged in the separator plate, puck, and/or 1-2 accumulator spring removed, plastic balls removed. Those all make it shift harder from 1-2. Just replacing the puck and the accumulator spring, if they are missing, will most likely resolve it. It did for me....

 

[Stock Farm]

Thanks slowleak - I’m not a tranny guy so will bring it to a shop.
Was hoping to have whatever parts they need too bring back to normal...

 

[jckkys]

I had the same problem. Some, or maybe a lot of tranny guys are knuckle heads that put shift kits in everything. I had to buy an unmolested valve body to get the C4 to work correctly. Mine came from a junk yard '74 truck C4. they're getting hard to find now. The '77 shop manual has the specs for the springs and there needs to be some rubber balls replaced. The separator plate will have at least one hole they drill to be welded up,too.

 

[Slowleak]

Hi all - I have a 76 with a C4 and it shifts really hard form 1st to second (it was rebuilt last year) - My guess is that someone put in shift kit at some point in it’s life.

My question, where can I buy a ‘factory shift kit’?

Would like to bring this back to stage 0 as the factory had it and if it still shifts hard...not much more I can do.

Thanks
S

One thing to check, this is a long shot, is the vacuum can on the distributor. I drove a ‘74 for over a year thinking it had a shift kit. One day I replaced the vacuum advance can. After that it shifted perfectly. Apparently a hole in the vacuum diaphragm was causing loss of vacuum to the modulator on the tranny at low speed, right when it shifts from 1-2.....