When the tranny is cold and I put it into reverse it makes a very noticeable grinding or vibrating noise. As I drive it I can just barley hear the same noise every time it shifts. The noise seems to go away as the tranny worms up and with the heater and radio on and the windows up you can't even hear it when its wormed up. From what the previous owner told me the tranny was rebuilt about 20k miles ago and has a shift kit and Corvette servo. It has always and still does shift firm and fast but it has now started making a grinding/ vibrating noise. The fluid level is good maybe even slightly overfull. The tranny is in a 88 iroc-z with a 350tpi. Any help will be greatly appreciated.

 

Needs to be torn down and rebuilt. Autos should never grind, ever

 

After a little research and talking to some people at work I think my TV cable may just be set wrong. Someone at work recommended a good transmission shop to take it to. Today I started the car after work and it made no noise as I shifted into every gear with my foot on the brake. Today it was in the 50's, the day it made some noise it was only 28 degrees out. I hope it doesn't need a rebuild but I'll let a pro look at it to decide.