Title says it all....what are some things that cause this?

Take it up 60 when it starts vibrating and put it in nuetral. Does it still vibrate? If yes, then drivetrain related like driveshaft needs to be balanced...loose pullley...etc. If no then wheel, tire, alignment, bearing issue etc. On an older car most like ly reasons are out of alignment....front bearings need to be re-packed and adjusted and tires have extreme uneven air- pressure in them or rims are out of balance (threw a weight or something)

Junkyard Dawg; Number of things can cause this, hard to really be able to specifically identify everyone that would actually apply to your situation but here are a few to check out;

If wheel shakes also, you are probably in need of a front end aligment, tire balance (all 4 )

Drivetrain; Standard or Auto :confused: (you did not say) Either Clutch & Flywheel balance ( * this would pretty much vibrate all of the time though ) but also check driveshaft U-joints, driveshaft balance, front trans mount, trans output shaft bushing & yoke integrity, and in general complete and proper drivetrain alignment. I do know if the pinion angle is too positive at rest it will cause improper u-joint geometry and cause a nasty vibration as well. Also rearend, upper and lower control arm bushings ( are they original ) also yoke and pinion shaft's bearing preload, I had a problem in my old Z28 that drove me nut's till I found that problem :D

PS: Vibrations can be a tough find but when you find the problem you will know it right away, and dont leave out the simple checks either, it could just be a bad tire with a broken belt too graemlins/beers.gif

ZIGGY454

Just my .02-wheel alignment will not ever cause vibration. Just don't want to see you throw money away because when folks come in and say "I need an alignment" we just align it. Then they come back a day later saying "my car still shakes at 60". Sounds like tire balance, 99% of the time if you have a vibration that doesn't start until 5-60 and you can drive threw, ie it goes away at like 80, it is tire balance/tire seperation.

Maybe I should clairify. Front end out of alignment equals uneven tire wear which, in turn, equals vibrations. Sorry.

zefhix
With all due respect you lost me on the throw it in neutral,does it vibrate? If yes, then drivetrain related like driveshaft needs to be balanced.???

At this point the tires are still spinning along with the drive shaft correct?

I once had a pick up with the same problem. got it up to speed and there was the shake. If I let off the gas it got much worse. turned out it WAS the u-joint and under load it would shake, but when I let off the gas and the rear "caught up" if you will, it was really bad.

There are many factors to check like ZIGGY454
said,don't overlook any of them for safety's sake.

Originally posted by ACLineman:
zefhix
With all due respect you lost me on the throw it in neutral,does it vibrate? If yes, then drivetrain related like driveshaft needs to be balanced.???

At this point the tires are still spinning along with the drive shaft correct?

I once had a pick up with the same problem. got it up to speed and there was the shake. If I let off the gas it got much worse. turned out it WAS the u-joint and under load it would shake, but when I let off the gas and the rear "caught up" if you will, it was really bad.

There are many factors to check like ZIGGY454
said,don't overlook any of them for safety's sake. No offense taken....
You sortof answered your own question, though. If you had let off the gas or put it in nuetral and it didn't get worse, it probably would not have been your driveshaft. Even though it's spinning at a same rate of speed, when you put it in nuetral the frequency it creates (vibration if you will) changes drastically vs. being under load. I had a driveshaft guy explain this to me in a fashion that made complete sense when I had a nasty vibration in my 67 Malibu.....hope I make sense!!!! I'm sure it won't work for everyone but it my case it helped isolate the issue so we could find it. Just a suggestion.... :cool:

Had bad vibrations in my Camaro once. Took me several hours of checking, but I finally found out that the transmission mount had separated. I replaced it, and everything was back to normal. It's easy to check, just put a jack under it, lift a little bit and see if it's intact. Wasn't all that easy to find out where to look though, I looked at everything like tires, bearings, driveshaft/U-joints etc before I finally found it graemlins/angry.gif