Ok heres the deal. I have a 2001 5.3 ECSB gmc. The trans was starting to slip at around 4000-5000 rpms in 2nd gear. I asked around and everyone said it was probably the 2-4 band that was starting to slip. So I brought my truck to a trans guy and had a wide 2-4 wide band, corvette servo and a transgo shift kit installed. Got the truck back and it would run fine from a dead stop if I would floor and leave it floored though all the gears, but if I would floor it at around 50mph it would shift down to 2nd, rev up high around 5000 rpms then slowly grab 2nd gear. And if I put it in 2nd on the column going anywhere from 20mph on up and give it 1/2 or full throttle it would rev up to around 5000rpms then start to grab. Now it won't even shift into 2nd. Just driving it slow it will rev up to around 3000 then shift to 3rd. If I floor it from a dead stop it will pull 1st rev all the way up to the rev limiter and not shift into 2nd, when I let off it will shift to 3rd. Trans guy said there might need to be a longer pin installed for the corvette servo? What should I do?

 

When he put the band in what shape was the drum in? Also how is the band clearance? Do you have a cut seal for the 2nd servo? Also how is the 1-2 accumulator piston? If its cracked the band could be draging when it shouldn't be. Or could create a flare. All of these things will cause band failures. Good luck!

 

Same exact thing happend to me. But i cant give any tips on what to to, i just got a new tranny. sorry