I had the 4L60E tranny of my 2001 Tahoe rebuilt by a friend. He is doing trannies for more than 30 years, but he is only familiar with the old-style mechanical transmissions. There was a bad bearing and clutches and the brake band was worn out.
After I put the tranny back in the car, it did not shift propperly. I found out that the big round connector was not connected properly, after I fixed that and erased the error codes in the computer, no new error codes showed up but the transmission still doesnīt shift as it should.
When I shift in OD or D, it stays in first, when I shift in 2, it shifts up to second. Reverse, neutral and park works properly.
Mechanical the transmission should be fine after the rebuilt, but we didnīt change the solenoids.
What could be the cause for that problem? Could it be a bad solenoid and is it possible to check / change them with the transmission in the car?
Thanks for help!