1991 GMC Truck • V8 4WD Automatic • 34,000 miles

I have a 91 gmc 3500 6.3 diesel dump truck and had the transmission rebuilt about 10,000 miles ago it worked great till I pulled it out my garage in forward and when I tryed to back it wont move but the motor has a load on it it will not also go in neutral it will acualy go forward and when I put it in park it does the same as when I shift in reverse the motor just has a load on it but wont move or alow the moter to rev free when the gas pedel is pushed any idea what I can do to ck it to fix
April 18, 2011.

Take it in to the shop that rebuilt the transmission. You should have a warranty on it.

Jul 18, 2011.