Trans

[Holt50]

97 GMC Yukon 4x4 5.7 358000 miles. Truck shifts from first to second st 3500 rpm. If I really get on it it won't shift out of first.
Any ideas.?

 

[drakon543]

stuck in 4lo, piston seals are going bad in the trans and it needs more rpms to get the pressure it needs to shift. lastly faulty tps it thinks your pressing the pedal farther than you actually are.

 

[Holt50]

Not stuck in 4 low it was rebuilt two year ago. The tps is where I'm going tho look tomorrow. Thank you

 

[drakon543]

as far as the xfer case being rebuilt is only a portion of issues that could cause it to be stuck in 4 lo. dash switch could be bad tccm could have a problem or the neutral shift selector could be faulty. tps is an easy cheap one to go after tho id probably start there myself.

 

[Holt50]

as far as the xfer case being rebuilt is only a portion of issues that could cause it to be stuck in 4 lo. dash switch could be bad tccm could have a problem or the neutral shift selector could be faulty. tps is an easy cheap one to go after tho id probably start there myself.

 

[Holt50]

Where's is the tps

 

[Holt50]

Where is the tps located.

 

[Holt50]

I'm sorry I meant the transmission was rebuilt

 

[drakon543]

ahh ok the tps is located on the drivers side of the tb.

 

[drakon543]

when i first bought my 97 it was stuck in 4 lo and i didnt even know it because it practically skips first gear and seemed to wind out and hang. i thought i had a transmission problem at first. combination of problems caused that tho. front actuator was shot blowing the fuse. the neutral switch wasn't sending the correct signal to allow me to shift it out of 4lo. and the push buttons weren't working correctly. replaced the front actuator and it stopped blowing the fuse. replaced the neutral shift selector on the side of the trans and i could shift it out of 4lo but it would shift right back into it. replaced the push buttons inside now i have an operational 4wd. as far as the tps its a common failure and can fail in multiple ways. it will either fail completely and you should get a code. the sweep will partially fail causing the ecm to see a fluctuating gas pedal or the position will be off. or you can end yp with a dead spot which will cause the engine to bog at certain spots in the throttle. something else i didnt think about until just now you could have an improperly adjusted kickdown cable. i could be wrong too i cant get outside and look at my 97 due to my knee to verify. check to see if you have 1 or 2 cables coming off your tb throttle connection. if you have 2 one obviously goes to your gas pedal the other is your kickdown cable. disconnect that one and take it for a drive and see how it acts. if its better it either needs to be replaced or is just to tight. with the flap closed you should have a bit of slack on both cables not much tho.