4L60E not shifting, always in 3rd

[alone_and_insane]

Last weekend I drove down to Indiana (about 350 miles). A way down the road, I noticed that my revs were unusually high most of the time (about 3500 rpm). The transmission was very reluctant to shift into 4th, and when it finally did, it only did so on a downhill incline (I was using the cruise control). When I got off the highway for some city driving, the car shifted really hard on the 1-2 upshift, enough to chirp the rear tires under very moderate acceleration. It always shifted hard there, but not nearly this bad. And now when it did, there was an audible thump! sound. I stopped and ate with some friends, so the car sat for about 45 minutes. After that, it worked like it always did. When I drove it home on Sunday, I went about half of the trip on the highway without it ever shifting into 4th. I pulled off the highway for a pit stop, and when I got going again, I realized the car wasn't going in 1st or 2nd either. It just started off in 3rd. I checked my ATF yesterday and found it to be a little low, so today I added some and drove around a little bit to see what it did. No difference, just always in 3rd. I even put the shift lever into 1, 2, and D (no square), and it made zero difference. HELP!

car is a 1996 Z28, I bought this trans this spring with 3k on a rebuild.

[1BADAIR]

codes?

[alone_and_insane]

haven't had it scanned yet. where should I take it for that? I feel like I really shouldn't take it anywhere like this.

[CHZBRGR]

ruh roh!

sounds like the tranny might be taking a poop.

[klrlt1]

Prolly a poor Rebuild

[c0ncEpT]

Trans is going into limp mode. Could be blown up or just a small electrical issue. You need to get it scanned.

[Dummybait]

hell.. take it to an advance autoparts or autozone. They scan for free, just make sure you are the one looking at the codes when you write them down...

[alone_and_insane]

Trans is going into limp mode. Could be blown up or just a small electrical issue. You need to get it scanned.

There's an Autozone about 3/4 mile from my apartment, so I could probably take it there. Somebody else on CamaroForums also suggested it's an electrical issue.

[alone_and_insane]

can anyone here recommend a good transmission shop in the Sterling Heights area? Got it scanned, turns out it's just a connection (insert MAJOR sigh of relief here).

[alone_and_insane]

I took the car to Aamco Transmissions on Van Dyke yesterday. they had to replace the shift solenoid. $250 of work FTL. But hey, it sure beats a rebuild.