Technical c6 after rebuild questions

hello all i need to pick yalls brains alittle i just rebuilt my c6******* and i can get reverse and drive but not auto shift when in d postion i can get a shift up if i move the selector to 2 postion but if i go back to d postion it drops down and screams at me lol just wondering if anyone would please give me some things to check to get my auto shifts for all gears i did take the valve body out after installation and reclean and added a shift kit but no change i get no change in the engine at all if i shift the selector from d to 2 or 1 while sitting still in shop but if moving i can get the one gear change please again just point me in a direction to getting it back going and thanks in advance.

 

Check vacuum at the modulator. Make sure the rod is in the modulator. The 1-2 shift is controlled by the modulator.

 

2nd that. When I ha my ford with a c6 the line fell off and would only shift 1-2

 

i will check that and see but when i did the rebuild it all looked fine guess i am needing to get a vacuum tester thanks for the info hopefully that will fix it

 

If you have already gone back through the valve body and still have no shifts, we will****ume the valve body is ok at this time. Make sure the kickdown lever isn't jammed in the passing gear position. The other shift controls are the modulator system, make sure the valve, pin and modulator are installed correctly and valve moves freely and has manifold vac. to it. The last control is the governor system. Did you take it apart and clean it? Forget to tighten it up after installation? Break a sealant ring while****embling?
Good luck with the problem.
Bill

 

If vacuum to modulator is ok, probably the governor is stuck. Very common problem on c4 and c6 transmissions after overhaul. There used to be a governor spring available from , I believe, Transgo to fix that problem. They are still in business and make great shift kits. Their Hotline number is 626-443-7451 8:00 am to 4:00 pm pacific time, closed 12:00 to 1:00 for lunch. Call them, and the tech will walk you through the diagnostics. This was always a free customer service.
Bud

 

thanks buddy i will check on that a governor spring sounds good i think my shift kit for the valve body was from them thanks again i will update soon i have to wait till this weekend to work on it tho working 12s this week

 

Okay so how bout no preload on modulator thanks everyone in advance.

 

Modulator should be adjustable, with a small pin/rod between modulator and valve. Use single line vacuum modulator connected to manifold vacuum, not ported vacuum at carb. Bud

 

thanks i know its adjustable but with the adjustment screw flush with the******* i used to have preload now none so i bought a new one and will see if it has a preload now thanks for the info.

 

Update all trans is working great!! Turns out it was the governor. I cleaned it again and that fixed it. Side note anyone ever heard of a failing steering pump screaming? Thanks again for all the replies.