I installed a 1983 automatic transmission in my 1985 rx7. The car vibrates when drive and reverse are selected. All of the parts are from the 83. I did not change the front balance weight. Both engines are 12A. I did not remove the pilot bearing.
Vibration felt when transmission is in drive and reverse. Did not change front eccentric shaft balance weight. The transmission and all parts came from a 1983 car. The donor car sat for over five years.