Hello Everyone. I have a 2008 wrx and it's developed an intermittent vibration / steering wobble at highway speeds. I'm not a regular when it comes to forums, but I'm hoping the masses might be able to help! The car feels solid then just starts shaking and it feels like I'm driving on marbles. Then will fade out again. Tires and wheels have been checked and Road Force balanced with no issues. Tires are also brand new because after having the prevouis new tires, bought a month ago, double-checked on the Road Force machine, the tires were found to be "junk" as per the dealer. Struts have been replaced. Both axles replaced. Everything else all checked out on three different occasions by mechanics. "Everything is tight and looks good", is what I keep hearing. (Refering to the suspension, steering rack, U-joints, etc.) I also keep hearing that this might be a bit of a chronic problem? Anywone having the same issue, and a possible sollution, or even a direction to look in?
The one strange thing and only possible clue I want to mention is, during the last front brake job, I was given regular Impreza rotors by mistake, and without paying attention, I installed them. The vibration went away, and for two weeks I was really happy with the car! Then once I started getting excessive brake dust and squeeky brakes I took a look and realized I had too small of rotors on. I replaced the pads and rotors with proper equipment and the vibration was back again. It's almost as though the front end can't handle the extra centrifugal force of the larger rotors if that makes any sense at all! The rotors have been checked and are not out or round or warped. Calipers have also been checked and are not causing the brakes to hang up at all. I do have 18" aftermarket wheels, with spacers, and I've read that the oversize wheel may cause an issue? Not sure if that's true or not. The outter diameter of this set-up is the same as the stock 17" tires. This car is driving me nuts! Thanks in advance and sorry for the long post.