Mechanics

SEEMS TO SLIP OUT OF GEAR IN REVERSE ON AN INCLINE

1997 GMC Truck • 90,000 miles

This is a 4WD automatic with the 5.7L V8. When backing up on level ground all is OK, but backing up on even a slight incline and it seemingly slips out of gear and makes a loud spinning sound like two pieces of sheet metal rubbing. The transmission was taken out and inspected by a transmission shop who only changed the filter and one band, but otherwise they said it was like new and the fluid was clean. The transfer case has been disassembled, inspected, and re-assembled. There was a problem with the electric motor, but that was repaired. Still has the problem, however. The guy who worked on the transfer case says it's the tranny, the tranny guy says it's the transfer case. Thanks in advance for any help! - Casey
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CREnvy
July 12, 2012.



If you put in two wheel drive will it still slip and make noise?

Saturntech9
Jul 12, 2012.
Yes, the problem is there regardless of whether it's in 4WD or 2WD.

Tiny
CREnvy
Jul 12, 2012.
Then it sounds like the transmission also if it only does it in reverse again it sounds like the transmission. With it in two wheel drive there is no torque going into the transfer case so if it was the transfer case the noise and slipping should have stopped.

Saturntech9
Jul 12, 2012.
Thanks, that makes sense. Guess I'm going to have to find a better transmission expert than the first one.

- Casey

Tiny
CREnvy
Jul 12, 2012.
Your welcome thats what were here for. The guy you paid to fix it should still be held accountable for the repair you paid him to fix it.

Saturntech9
Jul 12, 2012.
Also the fluid level in the transmission is full correct?

Saturntech9
Jul 12, 2012.
Yes, it was filled with new fluid when re-installing the transmission.

One other thought, it is possible that this is an electrical problem, say in the PCM?

Tiny
CREnvy
Jul 12, 2012.
Since we dont know the cause anything is possible but the noise is what scares me. Sounds more like something not put together correctly or broken and not holding the reverse gear. If you were just loosing reverse with no noise then I would suspect maybe just a electrical/computer issue. Also I would check the transmission level is full for yourself. Just to be on the safe side.

Saturntech9
Jul 12, 2012.
Did you ever find the answer to tbe problen you are having.I have the same motor and 4wheel drive having same issue with reverse on incline slipping out. Transmission is rebuilt up to spec and under warranty and has no issues. Have not physically looked into tranfer case but I have been told that if the the chain is slipping this would cause the problem and noise in 2 wheel drive.

Tiny
Justinrlee1988
Apr 11, 2014.