I already searched and just want someone input on this. I just installed my new function and form coilovers. I had shaking under acceleration before this install but was less noticable bc my springs were way softer. Now with the stiff rates its bad. I know its not my motor mounts bc they were replaced when i swapped motors with es inserts. I was wondering if this would cause it. I am almost positive when i had my wheel balanced i had a weight on the outer lip and on the inside lip of wheel. I just checked and the weights that were stuck on the inside of the wheels are all missing. I was wondering if the inside weight falls off would it cause a harsh shaking felt in the steering wheel and floor under acceleration. It also shakes when cruising about 60 mph. Please help thanks.

 

Could be a couple of things wheels needs balancing, are they after market wheels, also might need hub rings for them, also might be an axle problem, maybe bent wheel etc!!!

 

Sounds like a bad axle to me. Exact same symptoms in my buddies Civic.