When I drive down the road I notice a little shake in the car. It goes away in 3rd for some reason. It's only bad in fourth. I have balanced my wheels and tires and put new bushings, springs and some other component to update the front suspension last summer. I was just looking for some possibilities so I can look there first. Thanks

 

sounds to me like a vibration in the trans only because it doesnt do it in 3rd id check out the fluid

 

Sweet car Imprtslyr! Got one just like it. My first thought would be a slightly bent rim but the wheel balancing should've picked that up. Next guess would be a bad tire. One might have a bulge or broken thread inside that could give you shake at certain speeds. I've seen and heard of more generic tires getting flat spots if they were ever locked up skidding or being parked in storage on concrete for long periods of time. I don't see it being the transmission. 3rd gear must be that certain speed for whatever wheel or tire that is acting up. That's my opinion. I'd start there before looking into the drivetrain. Good luck!

 

Well the wheels and tires are brand new.. I mean we bought them last year but still they have very little mileage on them. So I hope its not them. I dont know about the transmission. It has alot of hard miles on it so maybe. I'll check the fluid this weekend. RS-Z/28s are the best! Click on my name and it'll take you to my youtube page to see it in action.

 

i would still look at your tires they might be out of round from the factory. same thing has happened to our 34 ford. put new tires and wheels on the car still had a shake at 55 rebalanced the wheels still shakes try having a tire shop deflate the tire and rotate it 180. then rebalance. it took alot of the shake out of the car.

 

Alright I'll try that as well.

 

Can you feel the shake in the steering wheel, or just throughout the car? If it's felt in the wheel it's definitely in the tires or wheels. Otherwise it could be tires, wheels, or even driveline. Might check the U joints to see if they are worn enough to be sloppy. A good test is bumping the car in forward slightly, then reverse to see if you hear any "clank" that would indicate sloppy U joint.

 

as a mechanic at a chev dealership i do a lot of warrenty work,had a customer in complaining of shake,vibration between 90 and 110 kph,it was brand new car took an identical car except it had michelins instead of goodyears,fixed it and the goodyears were brand new,customer s..t when told putting goodyears back on and he would have to take it up with goodyear.it dont matter if somethings brand new,try other tires even if you can only change two at a time.thats where i would start goodluck,nice car