Bad Vibrations

[cobraman302]

I have an 86' Mustang 5.0 Coupe 5 speed. The problem im having is that its making a bad vibration ot higher RPM's like around 3000 an on up. This vibration even occurs when the car is running at idle sometimes. I have put a new clutch and flywheel in it and the problem just got worse to where i can hear a noise coming from the rear of the car. I have even replaced the yoke, and u-joints. I need some help, I have tried just bout everything.

 

[hillie16]

Have you done any driveline mods? (i.e. gears, driveshaft?) Stepping up the gears can cause the vibration, as the stock driveshaft is not balanced correctly.

 

[cobraman302]

There are 4:10 gears on it. But why would it still virate at a stand still when it is revved. And the driveshaft is stock, which was the first guess, but a guy told me that it could be a wrong crank in the car. Something about they balanced them different before 81, and when the motor was built there could have been an older crank put into it. :shrug:

 

[hillie16]

DOH yeah I didn't think about that, forgot you said it did it at idle to. I would look into the crank issue.

 

[HUB90LX]

Check to make sure your vibration damper isnt coming apert. That'll do it for sure.
HUB