So this is my first automatic car and dont know much about them. Anyways Im trying to figure out if my problem is tranny related. I have a 97 SC4 and occasionally seems like more when its downshifting there is a sudden crazy vibration coming from the rear then goes away just as fast as it comes. The feeling is like when you drive off the road and hit the man made grooves on the side of the road that wake you up when your drifting off,?

 

anyone know anything about auto tranny's ??

 

Replace your transmission mount. It will more than likely fix that issue and maybe even a few other vibrations (unless its the transmission itself)..

 

could be your diff is loose...check the bolts.

 

2 things as stated above, Trans mount is most likely bad and the rear differential bushings tend to get real soft and loose so fix those and you should be golden!