1996 GMC Sierra Truck not shifting

invest0rs · September 28, 2016

Hello to all. I really need some help. My 1996 GMC Sierra Truck (4.3l Vortec) just all of a sudden just decided to not shift. The shift lever (This is an automatic) shfits fine when the brakes are depressed, no problem. But I can shift to any gear but nothing is happening. The engine sound does not change and I can tell that the transmission is not at all engaging. So it seems that the problem is happening before the transmission since the transmission is not being told to shift. Again, no difference in engine noise and no sounds are heard when shifting. I checked the cable connected to the transmission and it is fine and all electrical connectors are connected. I checked the transmission fluid level and it is fine. What else can it be that would be causing this issue to happen. Are there any fuses that could cause this to happen if blown. It drove fine when it was last parked and now it does not. Any help would be greatly appreciated and I would like to thank you in advance. Stacey

BoatRDavid · September 29, 2016

Stacey,

It could be that the torque converter has quit (?). It is ahead of the transmission. If it failed there will be no connection between the engine and the transmission. I had this happen in another vehicle. I don't know why it failed.

invest0rs · October 2, 2016

OK, so just to update, it was the Torque converter. Actually, the torque converter was fine. However, the 3 bolts holding the torque converter to the flex plate was not. One was missing (backed out), one was sitting in the bottom of the bell housing (backed out), and one bolt sheared and was left in the torque converter. No telling where the head of the bolt is. It looked like the flex plate walked about a 1/4" around the torque converter. I would guess from the looks of it it has been pretty loose for quit a while to have done this damage. Has anyone ever seen this before. And there has been no work done on the transmission or torque converter.