My 98GS4 has modified suspension a while back and it drove fine. Less than 2,500 miles ago, I changed out the power-steering pump and added adjustable tie rods along with a wheel alignment. About 1,500 miles ago, I notice a light vibration (maybe shaking) coming from the steering wheel and the car drifts to the right. Any ideas on the cause of the shaking . . .

 

wheel balance and/or alignment is off still
check the tires and see how they are. tires can cause pull as well

 

I understand that it needs another wheel alignment. But, do you have any idea what's causing the alignment to be off? And so soon???? I don't race nor drift, so . . .

 

check the tire pressure too. same thing happened to me, everything was fine untill one day i was driving and it started vibrating a little. thanks to the stupid roads in oakland, my wheels were off balanced and i had to rebalance them again.

 

Could be the ball joints, tire pressure, lugnut torque, or a host of other things.
Do wahts cheapest first. I had vibration until I loosened all the lugs and torqued back to manuf. spec. (76 ft lbs). VIbration was gone. A lot of shops will hit them with their impact at over 100 lbs then check to macke sure they are at least 76lbs. Your alignment could also wander due to bad bushings.

 

regular driving can knock it out. hitting curbs/potholes etc