I am having problems with my T56 in my 96 trans am. The car will not shift into third gear. When I push in the clutch and try to put it into third it just stops. After the stop you can push it through and then it will start to grind gears. Third gear is the only problem. All the other gears and reverse are fine. They shift smooth with no grinding.

What I have done. The car has a stock flywheel that is smooth and is not heat checked. The flywheel has a new pilot bearing installed. It is a new stock replacement clutch. I measured the thickness of the friction disc and it is right where it is supposed to be for thickness. The throw out bearing is new and the clip is securely in place. The clutch fork is tight and properly installed. I just installed brand new hydraulics. The hydraulics have been bled. Transmission is the same with both the new and old hydraulics.. The trans is filled with synthetic ATF rated for GM vehicles.

The previous owner told me the transmission worked fine for him when he pulled it out. The only thing I can think is that something internal on the transmission is messed up. Is there anything else I could be missing?

Thanks for the help
Ben

 

Shoebox has the T56 shop manual available for download. I would suggest the troubleshooting chart in Section 1 - not great, but helpful. If you have ruled out the external causes - worn pilot bearing, improper clutch adjustment, misaligned bell housing - then you would be looking at things like worn shifter forks or fork pads, damaged gears, damaged synchros.

4th Gen LT1 F-body Tech Articles

 

3rd-gear specific means it's probably not clutch related and needs teardown.