Quick history, 2003 Suburban 300,000+ miles, I rebuilt the 4l60e at just over 200,000 so almost 100,000 on the trans since rebuild. I put all the recommended upgrades to try to bulletproof it. It’s done well with the only issue since being an occasional start in 2nd gear which I installed an oversized AFL to resolve and no issues since. That was about 10K miles ago. My son was driving it this week and it lost 2nd and 4th. It shifts from 1st to 3rd and will not shift to 4th. No slipping just doesn’t shift. HP tuners shows it is commanding 2nd and 4th but it never shifts. If I put the gear shifter in 2 it just stays in 1st. If I make it downshift from 3rd to 2nd either by flooring it or manually pulling it down to 2 then it free revs like it was in neutral. He drove it to school fine, left school and it wouldn’t shift 2 and 4. I tore into it today and the servo cover has about 1/4 of play so that seems to tell me the band is burnt up. Pulled the servo and it looks fine, pulled the pan and it was pretty clean with a small amount of clutch material on the magnet. Is there anything else I should check before I assume that the band is burnt up and pull the trans? The trans was fine before this, what are thoughts on just pulling it and replacing the band and slapping it back together. Could there be some other issue that caused the band to burn up and it would just burn up a new band? If I have to do a full rebuild then I’m just going to swap in a 4l80e.

 

Forgot to say reverse is fine.

 

Sounds like it broke the band , happens. 100k miles i would be plenty pleased with the build .