hi everyone. i have a loud vibration that has been bothering me for quite sometime now. i have tried everything i could think of. the vibration is strongest between 40 and 50 (the vibration is less obvious above 50 because of exhaust noise and the rest of the rattles associated with an old car). this is driving me crazy. my entire dash vibrates and i can feel it through my steering wheel. i dont think it has anything to do with the drive train because it vibrates in neutral also. things i have replaced in an attempt to fix this: front wheel bearings, shocks, springs, suspension bushings, steering tie rods (outer and inner), ball joints, idler arm. in the process of changing the trans mount. any help on this would be greatly appreciated.

Hoang

 

You mention that it does it when you are in neutral. Are you coasting when you do this? Does it do it when the car is setting still, or only when it is moving down the road? You said that it is strongest when you are going 40 to 50. Have you tried balancing the tires? What about bumps or bad spots on the tires that would make it vibrate when going down the road?

 

Go to stiff motor mounts, ie - hockey pucks drilled w/metal plates on top and bottom like a sandwich.

 

My car does the same thing around 45-55mph, and I'm sure it's the tailshaft bushing in the transmission. I was thinking for a while that the driveshaft was out of balance, but it's done the same thing on 3 different driveshafts now. Yesterday I went under the car when I was fixing something else and grabbed the front end of the drive shaft and tried to move it up and down to check for play. There seemed to be a tiny bit of play, maybe .010-.020 at most. My friend's 240sx does the same thing and I'm sure it's from something in the back of the transmission (240-something-k miles on the transmission). With that said, maybe I should rebuild that extra transmission I have in the corner of my garage...

 

pretty sure it'll be your wheels... get them balanced. Put a different set on and see if it still does it.

 

Main possibilities:

Tire balance
Bent rim
Loose front wheel bearing
Dead shock
Universal joint
Rear transmission mount (this one's famous for mid-speed vibrations)

Engine mounts usually show up more in high-torque situations. If the problem is speed dependent but not rpm or torque dependent, it's either in the wheels/suspension or from the trans mid-line back.

Of your car sat for a long time in wone spot without being moved, you could also tires that have developed flat spots.

Have a friend in another car drive next to you when you're at the highest-vibrations speed, and have them look at your tires - - with failed shocks or bad balance problems, you can often see one tire visibly bouncing.

 

only when the car is in motion. i thougth it was the tires and wheels at first so i went and got another set of wheels with no change

 

Maybe an alignment check? If you need help, we can try to diagnose it. are those 5 lugs?

 

no they are 4 lug... i'll let you take it for a spin so you can see what im talking about.

 

Think it might be better if i follow you and check the 4 corners

 

aite that sounds like a plan. let me know when you have some time.