BlackBeard_lives

assembling my 4l80e rebuild. my favorite nick's transmissions rebuild video shows putting the direct clutch drum on the center support and plugging a hole or two with your fingers and applying compress air to the reverse or direct feed hole on the center support to push the piston on the direct clutch and use a dial gauge to measure the throw distance the clutch pack closes up when the piston pushes upward. but when i put air in the clutch isn't compressed against the spring, air just leaks out, not enough sealed in to hold air pressure and push the piston against the spring pack and close the clutch plates together. i put 3 sealing rings on the center support, leaving one out for the dual feed, since it didn't work i put a seal on the dual feed 2nd from top ring and clamped it with a worm gear clamp overnight to compress the nylon. gonna work on it again friday and get back to this post late that night. any advice appreciated.

also, my 02 4l80e from a gmc 1500 HD sierra i'm pretty sure didn't have a cone shaped cushion plate underneath the clutch stack, and my rebuild didn't come with one, but i'm learning my year transmission was supposed to have one? only 91-96 didn't have cushion plate???

thanks for y'all's time.

vorteciroc

I would be much more concerned with inspecting the Lip-Seals on the Direct Apply Piston.

But Yes you Center Support Sealing Rings can also be an issue.

Photos would help!

FranksCustomTrans

As mentioned photos would help. However in the cushion plate I never use those in direct , I replace cushion with a thicker 400 direct plate and then when I can add a clutch.