Okay here is the deal, I took my month old, broken-in WRX to the local dirt track and drove in the dirt for an hour or so, no extreme terrain or anything. There was no mud, it was all sandy soil. A huge thunderstorm came and we left the area when we got to about 35-40 mph, the car began to vibrate very very strongly. I slowed down, braked hard to see if there was something in the wheels. Nothing. Same problem. I went through many LARGE puddles to try and clean out the underside of the car in case there was something under there. Nothing. Same problem. I then stopped the car and checked for flat tires, no problem there. I even re-tightened each wheel bolt. No problem there either. Vibration continues. It is not a RPM sensitive vibration, it is a speed sensitive vibration. I cannot drive over 45 without shaking apart. Any ideas?

I was thinking maybe something wrong with the drive shaft. I have no idea what could have caused this shake. My tranny shifts fine and feels normal, you know, clunky, lol. Well I am taking this car into the dealer tomorrow...

ScoutWRX

You may have dirt on the inner srface of your rim's , My OutBack sport would have the same problem with ice. I would have to heat my garage to clean them off. Some times i could not drive home on the freeway it got so bad.


Blue

It would shake that bad with dirt or ice inside of the rims???

Yes, it would. This is very common with snow in the wheels. I don't know how muddy it was where you were at, but it's a good guess. Balanced wheels are very important :)

Greg.

Reminds me of that movie "My Cousin Vinny"

Ya got mud in ya tires!

Could be allignment too

You might have lost a wheel weight, which would make one of your wheels severely unbalanced and cause the symptoms you describe.

I once managed to get my wifes' Forester stuck in a snow bank and when I got out there was snow jammed in the wheels. The car shook like crazy until I cleaned the snow out.

Case closed, there was dirt/mud packed inside of the wheel where I could not see it. It didn't look like much but I guess it was enough. Either way, I don't like that one bit.
Thanks for the help guys!

Scout

You scared us for a minute thinking this "rally car" isnt as tough as everyone thinks it is. Alittle mud and dirt won't hurt a thing! :D

I did the exact same thing with mine. Took it out on a muddy road and caked some on the inside of the wheel. Mine didn't vibrate until about 70, but it was irritating. Cleaned out the mud and voila! :)

Yeah, I took mine out on a popular mud \ farm road that actually has a small stream running through the road. It was AWSOME... the stream was in between two hills I came up over the first hill at about 45mph (in the mud) and started to break. I sled a bit side ways but nothing to major, however I came to a complete stop in the stream its self (I was afraid of rocks or logs hiding under the water). Anyway, I just dropped it down into first and punched it right up the next hill. It was nothing short of amazing. Wish I would have gotten Pic's.

No problems, my friend that was with me said that he’s never seen a car make it down that road. Its by far the most fun I've had in the WRX yet.

But yeah until I took it to the car wash I had problems above 60mph or so.