I have a 1993 z28 which im almost sure has the 700r4. The problem is when i take off from a stand still and the RPMs go over 2 grand i will feel this hard thump under the center console when it shifts to 2nd. it feels like someone is hitting under my car with a sledge hammer. The rpms dont jump up when i feel the thump. Can someone please help me?! Ive looked at symptoms of different components of the trans but i just cant find a match. thanks

 

The transmission mount is broken.

 

that's what i would put my money on !!

 

That's the ghost troll of Rusty Jones telling you to come on down and take a look instead of hopping on the computer.

 

fixed thanks guys