Th400 diagnosis
 

well my car was running about 1/2 second slower and i narrowed it down to the transmission. Forward clutch pack looked like new. direct clutch showed hot spots on the plates and dark burnt rings on the clutches, intermediate was burnt up pretty good with alot of hot spots. Everything else in the tranny checked out ok.(air check) I run a full manual valve body.(cheetah) This is after about 2-3 years of abuse, what could cause the slipping? would it be ok to just install new clutches and steels?

Yes, pound in a full set of bushings, new seals, sealing rings, frictions, steels, and gaskets. Check the intermediate sprag and races. Closely inspect the inside of the drums where the sealing rings seal, check endplay, and tighten up with selectives as required. The frictions and steels are supposed to wear out, that's what they are for, to save the hard parts!.....Cliff

thanks.

I use a 4 clutch intermediate pack in my higher HP TH400 setups.

Does the valve body require you to leave a sealing ring off the center support?

If you haven't done so already, replace the snap ring that holds the intermediate sprag in place with a spiral ring from a 4L80E trans. Higher HP motors tend to cause the original snap ring to expand and fly off, Ask me how I know. :)

if you have a high stall torque converter and you want to firm up 2nd to 3rd gear then removing the snap ring from center support will do that !

:doh: sealing ring. :D