I have some moderate vibration in my drivetrain after 70 MPH. It gets worse when you run up to 80-90 and let off the gas. I had my wheels and driveshaft balanced, but the vibration is still there. Can the half shafts be that far out to cause a vibration at that speed?? Anyone have any ideas?? Thanks in advance..
Chris

 

TTT

 

I can't tell you for sure what your problem is; but, many people with performance automobiles don't understand that eliminating problems with vibration is a different game than on the family car. The important thing to keep in mind is a Corvette suspension will unmask vibration problems that the luxobarge vehicle will never see -- those narrow, bulging sidewall tires and soft suspension will simply absorb that small runout.

I suggest the first thing you do is find someone that has the Hunter "Road Force" balancer http://www.gsp9700.com/pub/features/intro.cfm and have the tires re-done. This unit has a wheel that puts about 500 lbs of force against the tire to simulate the weight of the vehicle on the tire so you have realistic conditions for detecting vibration.

The stiff suspension and stiff, straight sidewalls on these vehicles are great for transmitting every tiny variation to the driver's seat.

With these vehicles, it is probably better to find someone that has the Hunter, or same type, of balancer and buy the tires from them.
The reason is that sometimes there are tires that will never be able to be indexed on a given wheel to eliminate all the runout. In a case like that, the tire dealer can simply put that tire back and pick another one that will.
If you take your own tires in to have balanced, they are the only tires the tire dealer has to work with (they aren't going to exchange the tire you bought somewhere else), even if they have the Hunter balancer.

At the OEM assembly plants, even the luxobarge has wheels and tires done this way.

Been there, done that.

Tom Piper

 

sounds to me like your rims not tires. i had a similar vibration when i used repaired ss wheels that my brother has smashed up a curb when they were on his camaro. they would balance and everything seemed smooth until a certain speed. i always thought it was somethng else. when i replaced them with different wheels the vibration completely dissapeared.

 

I have another set of wheels and tires I can try. I have always had some vibration, but it is much more noticeable since I did the D44 swap. The rear was built by DTS, and the driveshaft was balanced by Driveshaft King. I did remove the damper from the transmission yoke before I had the shaft balanced, because the elastomer was shot. I was assured that this would not affect the driveshaft balance, but now I am wondering...
Thanks for the input guys..
Chris