96 impala grinding vibrating noise around torque converter

Best bet is to get under there a pull the inspection cover off, if your lucky, the flexplate is cracked, if not...get your wallet out.

I took the cover off but didnt see nothing wrong with the flexplate. there was not metal chips on the cover. It happends when I firt taking off. maybe when tranny is going from 1st to 2nd. what could it be?

Might test the electronic connections on this tranny. May be a shift silinoid going bad.

I just replaced the two shift solenoids and the lock-up solenoid. could it be the PWM control or the 3-2 on/off solenoid?

Where is the shift solenoid located? Is it bolted to the side of the trans or is it under the pan?