Recently I've been noticing that when i accelerate at a normal speed when the car shifts somewhere around 35-45mph, it shakes the whole car. It does this unless i let off the gas or push more. It doesnt do it at all when i accelerate fast, it's an auto. I don't know if its normal, but i noticed it happens sometimes in the 93 sable i sold to my parents. guess im wondering if it happens to anyone else and if you think it's serious.

 

 

I think its actually the converter unlocking when the car shifts into OD. Turn OD off and get up to 40mph and see what happens.