Tranny slipping

[ls1ram]

A rebuild would be ideal. If you do decide on a rebuild some basic parts would be the alto 2-4 band, corvette servo, billet overdrive servo for towing in OD. borg warner sprag with the dual cage, beast sunshell with sonnax extra wide rear sun gear bushing sonnax exrtra wide rear stator support bushing, rebestos 3-4 z-pack works very well, or the red alto 8 clutch setup with kolene steels(this makes 3rd gear shift a bit firmer)

If you run the truck hard I would add a sonnax sleeve kit to the input drum, 4l65e hardened and shot peened output shaft, drill 3rd gear feed hole to .093.

If you have big power in a heavy truck make sure not to set up a hard 1-2 shift, it will snap an ouput shaft in a heatbeat.

[medic/z28]

I did a simple filter, oil drain and fill with 5-6qts and it was night and day difference. Oil hadn't been changed in about 60-80,000 miles. Do the basics first. I first noticed it when I did the new exhaust and tune. I took 60-80% of TM off so it was slipping bad.