Tranny Problem

[copenhagen]

Well maybe someone hear can help or knows a bit.

 

Got this one customer whos tranny was replace becasue it was slipping a bit and would hang up or pop down a gear so we changed the tranny... Now new tranny in it would still stay in the gear when the tranny downshits, you got to let off the gas to get it to upshit...so we talked to the tranny experts for over 2 weeks, replacing speed sensors, TPS, and a solenoid with the same results... another work of mine say to give him a new tranny becasue I found 2 bolts in the pan and the rear output seal was leaking bad.

 

So i install the new tranny and the same thing, but when its in 4th and you give it a little gas it pops down to 3rd right away...and still hangs high when down shiting and doent upshit until you let off the gas

 

The connectors look good on the tranny and at the TCM.. any ideas?

[sillyazz]

What kinda vehicle and year ?

[copenhagen]

2003 Gmc sierra 1500 4x4 reg cab.

 

Also, while on the scanner he had all 4 of his O2 sensors on the "check engine light"

 

The truck seems to lack power so we did a back pressure test on one bank, finally we decided to just hollow out that cats, lol.... he drives in the bush so it wont matter much