Usually, feedback though the steering wheel is cause by having an improperly balanced tire. I would check this first. If you have gone over a large bump and knocked a wheel weight off (or bent the rim), it would definitely cause what you are describing. A tranny mount could be at fault, but the Corollas seem to have a lot of redundant engine/tranny mounts to begin with. I doubt a break at one of them would cause too much trouble, but it is possible. It is more likely that one of them is just loose, if the problem is in fact a tranny mount. The only real way to check them is to get under the car and lift up on the engine/transaxle assembly with a prybar or jack while looking at the mounts. Any cracks or breaks will be obvious. I seriously doubt that a tranny mount would break after only four years, as they usually succumb to age rather than mileage. Have your wheels balanced if you have not already. Chances are that will solve the problem. Good luck!:lol: Regards, Aaron