Transmission slip in/out of 4th

[rockola1971]

Nope, no rebuilds. Just regular transmission services from yours truly. With it being just 4th gear I thought I had a decent plant of attack with changing the servo seals and the solenoids to eliminate that but now I've lost 3rd and I'm thinking it may be the 3-4 clutch. We'll see.

Yup. Your 3-4 clutch is now gone also. Likely caused by contaminated tranny fluid (2-4 band dust) which has worked its way into the valves, in between all your seals and their sealing surfaces, in between check balls and their seats on the separator plate. Now burnt clutch material has joined the contamination. Have a look at your fluid now and smell. You will likely find the fluid has turned brownish and smells burnt. Its over now. They never fail at a convenient time in life.

 

[NGAneer]

The end of the story goes like this. The 3-4 clutch was pretty well gone, most of the seals were completely worn out. The relatively new fluid had definitely taken on some material from within the trans. Took it to a shop where they went through the whole thing and rebuilt with new clutches, steels and new seals.

Had it back about two weeks now and it shifts like never before. With the BB tune and Corvette servo it barks the MTs into 2nd and 3rd. I stay out of it most of the time because the trans seems more aggressive that a plain OEM rebuild.