About a year ago I blew my engine on my 2003 WRX and just recently replaced it with a stock JDM motor and transmission. The swap went smoothly and took only a few hours to get settled into the vehicle and bolted down. The engine and transmission came attached so cutch should have been aligned by Subaru factory in Japan.
My issue now is that when I get up to about 40 mph the car shakes violently and will not stop shaking until I have come to a complete stop. I did disconnect and reconnect the drive shaft to put the new transmission so maybe the shake is from that? Ive spent quite a bit of time checking the drive shaft for any time sign of errors but haven't noticed anything unusual.
Things I have already checked: rotated all the tires, installed new front axles, brakes rotors are straight, engine and tranny mounts are bolted down tight, no strange noises coming from wheel area. I put the car on jack stands with all 4 wheels off the ground and got up to about 60 mph and the wheels are spun straight with no weird shaking so I am thinking the shaking can only be produced under load.
This vehicle was also put on a tow truck 4 times from when it broke (flat bed tow truck), to when I was able to fix it. Maybe the tow truck bent something? Ive read all the other threads about vehicles shaking and mine is definitely different. Please help!