jplassman

Tranny has approx. 5K on it. Vig 2800 was installed at that time. I very recently have been getting a mild slip with a moderate bump on the gas while in OD/ tcc lockup . maybe 200-400 at most , though I do not stay in it when I feel the slip start. Quick trans info: Raybestos clutches , Z-pack 3/4, Alto wide red band (new re. input Drum) round out the frictions. Sonnax pinless fwd acc, sonnax stator shaft, .490 boost valve w/ superior "blue" spring , beast shell , new sprags & bearings , and Sonnax 2nd & Superior 4th servos cover the major hard part hard part upgrades. TCC PWM is diabled as well.
Well respected local trans guy assisted me w/ the build. I dont think anything simple was overlooked , but i am no trans expert. I got to warm up on a 4t60e w/ a flared "stovepipe" which now has 30k and no probs.I am resonably familiar w/ 4l60e basics , GM tech manual was very helpfull there.
When punched on a roll in third (tcc unlocked) rpms come up to 2800 to 3000 and hold which makes me think the 3/4 pack is ok and that the tcc is the culprit on the slip. I still get a good solid feeling lockup , just now there is some slip starting . Trans didn't have any real issues prior and related valves inside looked fine. Converter issue ? Trans issue ? Does not feel like the pcm is pulling lockup. Would a line pressure check be the next step? Also have 6 quarts of Redline D4 syn. mixed in w/ castrol fluid as of 1500 miles ago.

jplassman

I should add that it takes a good amount of throttle for the pcm to unlock the tcc. Had pcm for less raise the misfire threshold to prevent tcc lockup from being pulled on occcaision and since then it seem like it takes a good bit more pedal to unlock. Is the tcc getting overloaded making this a tune issue? It takes a bit of a stab on the gas to notice the slip.