Ford Mustang Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
50 Posts
Discussion Starter #1
I just recently got the 4.10s back in the car, but now I've got a nasty harsh vibration that comes up right at 90mph. It manifests as a sharp buzzing in the shifter, and you can hear it throughout the car. What's weird is that if I'm on the throttle hard, it won't usually pop up until 100, but if I back off anywhere north of about 87, it shows up, then gets really bad as speeds increase further. I don't dare take it above 110, as it feels like the car'll fly apart. My question is, (to those who might know), would this be an unbalanced DS, or an incorrect pinion angle? Other than this, the car drives fine, no gear whine from the diff, nothing.

Any thoughts?
 

·
Registered
Joined
·
365 Posts
before you have it done you will have installed both. but do not count on even a carbon fiber driveshaft to cure improper driveangles caused by changing lower control arms or different springs. purchase a 15 dollar angle finding level from home depot, sears, hardware hank, or even ace. it then will be easy to determine if you need double adjustable uppers. bobn
 

·
Registered
Joined
·
1,724 Posts
Did you remove the dog bone?? If you did try putting it back on.
I had the same problem you are having the alloy DS did not help but putting the dog bone back on cured my problem.

Dwayne
 

·
Registered
Joined
·
50 Posts
Discussion Starter #6 (Edited)
bobn: the rear suspension is totally stock. Are the tolerances that bad in these cars? This is my first mustang, so I"m not sure what to expect.


46GTSBlown: what "dog bone" are you referring to?
 

·
Registered
Joined
·
224 Posts
The mustang has an iron vibration dampener on the "nose" of the pumkin. Some people calll it the moose ba!!$. IT makes a difference having that thing.
 

·
Registered
Joined
·
50 Posts
Discussion Starter #8
ah. I see. Yah, it's still on the car. I guess a new DS is in order...
 

·
Registered
Joined
·
219 Posts
How much work is it to adjust the pinion angle? I didn't get vibration until the 4.10's wen't in. I get it above 70 on deceleration and going down hills.

I really hope a new driveshaft will solve this problem, it's driving me nuts!
 

·
Registered
Joined
·
550 Posts
Amherst said:
How much work is it to adjust the pinion angle? I didn't get vibration until the 4.10's wen't in. I get it above 70 on deceleration and going down hills.

I really hope a new driveshaft will solve this problem, it's driving me nuts!
an aluminum driveshaft will solve that problem
 

·
Registered
Joined
·
31 Posts
I have the same problem and I've used Aluminum and Carbon Fiber dirveshafts and it is still there. I'm going to check my pinion angle. I <b>think</b> if the Pinion angle isn't bad you can adjust it with shims in the transmission crossmember. If that doesn't work, I'm getting a torque arm and panhard bar. I wanted one anyways and this is a good excuse. the TA and panhard will allow for the removal of my upper control arms and allows for pinion angle adjustment.
 

·
Registered
Joined
·
433 Posts
netwiz said:
I just recently got the 4.10s back in the car, but now I've got a nasty harsh vibration that comes up right at 90mph. It manifests as a sharp buzzing in the shifter, and you can hear it throughout the car. What's weird is that if I'm on the throttle hard, it won't usually pop up until 100, but if I back off anywhere north of about 87, it shows up, then gets really bad as speeds increase further. I don't dare take it above 110, as it feels like the car'll fly apart. My question is, (to those who might know), would this be an unbalanced DS, or an incorrect pinion angle? Other than this, the car drives fine, no gear whine from the diff, nothing.

Any thoughts?
if your car is, for all intents and purposes, untouched as far as the suspension goes, then pinion angle is likely not the problem.

This symptom sounds like classic driveshaft vibration.

you can actually try to diagnose this yourself by securing hose clamps around the drive shaft to see if the problem is mitigated or gone completely.
 
1 - 12 of 12 Posts
Top