[Steve Dzudz]

Hey all,
I have a 1997 Trans Am with an automatic. when I step on it from a stop, there's a grinding or thump sound. It almost sounds like the traction control kicking in, even when it's off. It only seems to do this when you step on it while at a standstill or rolling slowly. I know it's not a great explanation. I've looked under the car, I thought maybe the torque bar was loose, or the u-joints, but everything seems good. Could it be inside the transmission?

Just wondering if anyone has experienced anything like this (I know it is a crappy description)?

Thank you in advance!

 

[Nick's Transmissions]

Where do you feel it? In front of you, directly below or does it feel like it's coming from the seat or rearward of the seat?

If it's the transmission, it could be the rear gear train however grinding is rarely felt with an auto; you typically experience delayed engagements in drive or reverse where it feels like the vehicle is locking up until you shift back and forth between reverse and drive to clear the obstruction (usually pieces of gear teeth wedging and interfering w/the mesh). You get grinding much more so w/a manual (T56 in the case of the 93-02 F body cars) when one or more gears are breaking up inside the unit. Also check rear end and or motor mounts.

 

[Steve Dzudz]

Where do you feel it? In front of you, directly below or does it feel like it's coming from the seat or rearward of the seat?

If it's the transmission, it could be the rear gear train however grinding is rarely felt with an auto; you typically experience delayed engagements in drive or reverse where it feels like the vehicle is locking up until you shift back and forth between reverse and drive to clear the obstruction (usually pieces of gear teeth wedging and interfering w/the mesh). You get grinding much more so w/a manual (T56 in the case of the 93-02 F body cars) when one or more gears are breaking up inside the unit. Also check rear end and or motor mounts.

I'm sorry the explanation is very crappy. It feels more like a clunk, the best way to describe it is if you were to take off with the traction control on and the traction control kicks in. It only seems to happen at low speed. Seems to be coming from more the back, that is why I thought the torsion bar was loose or something like that?

Thank you!