i just bought a z28 at high speeds at about 85-90 then abuot 100-110 it shakes the hole trans and it feels like a vibraitor in my seet the stick shakes on it and everything people been tellin me it could be U joints, trans brackts or somthing else whats ur guyses ideas

 

maybe driveshaft, or trans mount?

 

Sounds like a warped driveshaft?

 

Could be a couple of things. It would help to know the year and some basic info about the car. miles, etc. Most people cover that with a sig. If your car is pre-98 and does not have the TSB, it could be the steel driveshaft. Give us some more info.

 

its either 1 or more wheels unbalanced or the driveshaft. Get the wheels balanced first. Then check into the driveshaft. A machine shop should be able to balance driveshafts for you if you need it.

 

My first thought would not be a warped driveshaft????

Start with the easiest problems and work your way towards harder and more expensive ones. You said you just bought it, the tires could be out of balance or improperly inflated, check on that first. A transmount would cause jarring at all speeds and even worse over bumps and rough roads, it could be U joints. If it has 3:73, or 4:10s and still has the stock driveshaft then that is definatly part of it, it can be fixed by getting an aluminum driveshaft. The LS1 shaft on gmpartsdirect.com will be fine. Good luck.

 

I might be wrong but unbalenced wheels and tires would vibrate at all speeds Right?????

 

To an extent. depens how bad out of whack they are. The suspension will soak up most of the hop at low speeds but when speed increases so does the intensity. An unbalanced drive shaft would be the same (except the suspension part)

 

So if he is getting a vibration at only 85mph to 95mph and 100mph to 110mph it is probably a warped drive shaft... RIGHT?

 

my 93 does the same thing..at exactly 85+ mph..until that its very smooth and theres no vibration at all. but once i hit that spot..vibrates like crazy! i from what ive read its the driveshaft. i got a used ls1 driveshaft for cheap..was plannin on tossin that in one of these days and see what happens.

 

Common problem with stoc steel driveshaft. Replace it with an LS1 aluminum ds and your good to go.

 

I will bet dollars to donuts that it is the stock steel driveshaft making the vibration. The aluminum is such an inexpensive and EASY mod.