TZ2884

iTrader: (14)

Around 60-75 mph the car starts shaking. Almost has the feeling of hopping and swaying. The front feels fine, nothing through the steering wheel it all feels like it's behind me.

I'm not even sure where to start. I plan on getting new rear tires soon but I'm just not sure that has anything to do with it.

Any ideas on where I should start troubleshooting?

19wagon63

sounds like it could be the rear tires, miss aligned rear end or possibly a drive shaft issue if you think it is behind you. If they fit you could try swapping the front and rear tires and see if the shake fallows. Good luck.

TZ2884

iTrader: (14)

Unfortunately they won't fit. How could I check for a drive shaft issue?

tta656

iTrader: (5)

Maybe a bent rim,bubble in the side wall of tire,bent axel..

spacemanspif

iTrader: (5)

Check the wheels for weights, sometimes they fall off the rim if not clamped on there properly. More info. will help too: Car lowered? (if so, what method did you use?), what brand and size are the wheels and tires? How old are the tires? Wheels lug or hub centric?

Pop N Wood

iTrader: (1)

Get under the car and torque every bolt you can get a wrench on. Especially drive shaft bolts. Check tire pressures too. Look for worn U joints.

Beyond that it is most likely tires, but if that doesn't work here is a good reference.

http://www.aa1car.com/library/vibrations.htm

TZ2884

iTrader: (14)

The car is stock height. Wheels are hub centric. The wheels are some stock old Trans Am wheels 15x7. The tires are some cheap brand I've never heard of, I'll have to check them when I'm around the car. The tires are definitely old.

Hope this helps.

TZ2884

iTrader: (14)

I'm really hoping it is tires.

Pop N Wood

iTrader: (1)

One thing I have found if I don't drive the car for a period of weeks/months the tires tend to flat spot making the whole car shimmy. The fix for that is to just drive the **** out of them for awhile.

TZ2884

iTrader: (14)

My brother mentioned that to me, and I don't drive the car often, but it seems like sometimes I can hop right in and take off and there's not much of a vibration at all. Then, maybe later that day, I get in it and drive and it shakes like crazy. It does it more often than not but it's still kind of random. I've tried to find a pattern but really haven't been able to.

The only thing that seems to be constant about it is the speed it starts shaking at, and that's somewhere right above 60mph.

TZ2884

iTrader: (14)

Hopefully I'll get a chance to check it out tonight. Any other ideas?

1970camaroRS

iTrader: (8)

My vote is that it's drive-shaft/u-joint related. Good luck, hope you find your trouble.

TZ2884

iTrader: (14)

Checked the u joints, no play in them.

TZ2884

iTrader: (14)

The car really felt fine all day yesterday. I bought some new tires for the rear also. I probably won't be able to get them on until next weekend at the earliest. Hopefully I'll know more when I get them mounted and balanced.

19wagon63

Keep at it you'll find it sooner or later.