ey Mr. Wiggles let me know how many miles you have on your SC 300 I have been working on Lexus for close to 8 years now, it sounds as thog your drive shaft is unbalanced but I can't be for sure without looking or driving the veh, but from my experence I have had to replace the drive shaft for that problem give me a hallor if you find out what it is it could vary well be your tires also but that would cause the veh. to shck rather then just the shifter.

hokkayh(Hawk)