vibrations at 75-85 MPH ...

[Jan Larsson]

Got some vibrations at highway cruise speed (well cruise speed in the UK) between 75 - 80 - 85 MPH

I guess this is the driveshaft .... I can try turning it 180 degrees and see if that helps or not but just looking for other ideas ... should I get the driveshaft balanced and that would cure it all the way 0-140 MPH ???

 

[Razor]

Sometimes the weights will fall off. And balancing will clear the 75-85 MPH issue. Altho dont know about 90-140

Your driveshaft shop should be able and tell the condition of the shaft.

 

[Roc87]

Had a vibration in my GN at around 70-80mph and it turned out to be a bad pinion bearing.

 

[fast400]

What was the result??

 

[Jan Larsson]

Got it balanced and it was off just slightly so a couple of new weights on there, also had two smaller dents on it ... they also cleaned it and painted it black for me ...

Anyway got it all back together but not driven it yet (pooring down with rain in this country ...) so will take it for a spin and see if it made a difference or not and will report back ... hope I can do it tomorrow

Thanks for the input sofar !

 

[Jan Larsson]

Had a vibration in my GN at around 70-80mph and it turned out to be a bad pinion bearing.

Eric, anyway to check that without taking the rear end apart?

 

[vacuum 6]

I had an odd vibration @ ~50-60...bell housing bolts came loose

 

[Jan Larsson]

Took it for a drive today ... couple of miles ... and man what a difference ... feels really good all the way up to 100 MPH ... just the interior rattling and a bit of "road feel" in the steering wheel.

Roads not perfect to get the right feel and I have all plybushing suspension (not engine or trans mounts though) so I do feel and get some road vibrations but the "shaking" I had is defenitly gone and it drives much better I must say.

So well invested $70 USD ... interesting how just a bit of off balance can do so much at certain speeds.

 

[Grumpy]

I can relate to this.. Guy's think just a little weight won't make a difference. Had a vibration in my Buick/Mazda when I first got it.. It would shake you out of the car!! Had the car on a lift and had it @ speed .. Didn't see a damm thing.. After pulling my last old gray hair out I noticed the BRAND new driveshaft didn't have any weights on it .. Had it balanced.. Needed a small weight .