I was having trouble with my t-56 transmission in my 2003 vette. The mechanic diagnosed the problem as an internal shifter mechanism fault. He recommended I replace the transmission.

I purchased a rebuilt transmission and had my garage install it. The car was now able to select all gears, but with grinding when selecting second gear. The transmission would grind when when up shifting and downshifting, and also grind when selecting while vehicle was stationary.

I then decided to get another rebuilt transmission, to minimize downtime and have the second one installed, and send the first one back for warranty/DOA. Once it was installed, the second transmission did not select 5th gear and would pop out of reverse, and pop out of 6th on the highway.

With no luck I returned this second transmission to the rebuilder and put the first rebuilt one back in the car. The rebuilder called me and notified me that the second transmission that I returned to him had the 5th and 6th reverse gear, 5th and 6th reverse shift slider, and all shift keys damaged.

He said that the cause of the damage was due to an improperly adjusted clutch hydraulic system. So now I have installed 2 transmissions and still am having difficulty.

Is there something that the mechanic is doing wrong with the install? Is there something other than the transmission that is causing this?