Broke trany mount twice. Shifts hard out of 1st and 2nd. Can the hard shift break trany mount? And what causes hard shift? Also what are good mods starting off. Not a daily driver. Gunna be a work in progress. Going to do most of work myself. It's a 94 z28.

 

Broken trans mount is a common problem. Every time you accelerate, the torque arm pulls up on the front torque arm mount, which is attached to the tailshaft of the transmission. That will tear a rotted rubber trans mount, which in your case could be 20 years old. Hard shifts simply increase the impact on the torque arm.

Hard shifts can be caused by a "shift kit" installed in the transmission, or altered PCM tables that control the 4L60E shifting. Do you know the history of the car/transmission?