QuestionDick, I own a 69 Camaro coupe. w/ 250 engine/2 speed powerglide trans. Stock! I have vibration in the car between 60 to 66-68 mph! I feel it slightly in the steering wheel, but more in the seat and consol by my leg. Its crazy because it doesn't always happen. I visually checked the driveshaft weights. They seem to be in place. U joints tight, I had Sears put three tires on the car and balanced. I took off the 4th tire and temporairly swapped with spare.[no difference].I had vibration before new tires, but it did get much better since new rubber. Maybe their balance job is faulty, or what else can I check?
AnswerMy guess would be a driveline vibration.
It is not only important that the driveshaft be balanced, but also the two end u-joints have to be in good shape, and phased right.
Further, it is very important that the angle that the u-joints have to accomodate is as close to 0 degrees as possible, so if there is any way that the differential is not pointed exactly at the rear of the transmission (and vice versa), or if the ride height is not exactly per factory specs, or if the motor and transmission mounts are not exactly right, you can get this sort of vibration.
The problem needs to be fixed quickly, as it is beating up on the rear bearing of the transmission, and on the pinion bearing in the differential.
I'd take the car to a driveline service place - there are various nationwide chains for this - the one I've used sucessfully is Driveline Specialties, but I know there are others. Just get on the internet or look in your phone book for one near you. They will figure out the problem and fix it right!
Good Luck - I envy someone with a plain Jane Camaro - everyone seems to be after the big block cars - but my druthers is for exactly what you have!
Dick
