Vibration

[JS29]

My 1970 Barracuda gran coup has a vibration that starts at around 50ish MPH. It starts out with the hood and fender shaking, by the time i hit 65 or so it has the steering wheel almost shaking out of my hand. New tire's on the front, four new torque trust wheels, fronts were road force balanced. I know the car has a summit disk brake conversion kit. I called summit today, the company that made them is no longer in business. Stainless steel brakes, the part # seas for ten inch brakes, my car has eleven inch rear brakes. Are the spindles different?  has anyone heard of aftermarket rotors being the sores of such a vibration.  This has been an ongoing problem sense I bought the car.       

[Rich G.]

If the steering wheel shakes it has to be in the front end. Obviously make sure everything is tight. I would jack the wheel off the ground about a 1/4 inch and spin the wheel. You will see if the rim is bent or a belt has shifted in the tire. Start there.

[Cudakiller70]

  while it's off the ground grab the wheel at 12 & 6 o'clock and try and rock it. Looking for anything loose like wheel bearings or something. Bushings ok? Shocks?

[dodj]

Shocks?

This is the first thing I would think if the vibe is getting that bad and the wheels and tires are already checked out and balanced.

I might be tempted to swap fronts to rears to see if anything changes.

Strut bushings are very important to the stability of the mopar front end. How do they appear?

[Cuda Cody]

New tires?  Did it have the vibration before the new tires?  If not, I would start there.  Sometimes wheel weights can fall off or they just didn't get them balanced right.  I've also had brand new tires that were garbage.  I'll never buy BF Goodrich ever again.

[Scooter]

I've had a friends car do the similar, turned out his u-joints were shot. Is the vibration tied to the actual speed of the car or engine rpm?

[anlauto]

Are the aftermarket rims seating properly on the hub of the rotor ?
Maybe try swapping out the wheels altogether just to see if the vibration goes away.

[Chryco Psycho]

Is the center register hole the correct size on the rims , bolt pattern in inches not 114 mm
I agree with Cody BFGarbage tires are terrible , even when balanced they can be waaay out of round & fail in 100 miles or less just Junk

[Racer57]

When the vibration is at its worse, quickly put it in neutral and see if any changes.

I fought a vibration for 3 years. Changed brake drums, driveshaft and tried different degrees of tilting rear axle. Finally by accident found out the output shaft bushing on my Tremec was shot.

[JS29]

@Cuda Cody This vibration has always been there. It was worse, the B-F Goodrich tires on the front were bad. it had a pull that switched sides with the tires. two new tires purchased, shake was at a higher speed. Road force balance showed one front wheel and one rear wheel were bad. Four new torque trust wheels purchased, balanced shake persisted, fronts road force balanced. Front end alignment performed, not enough caster. put the car on a chief E/Z liner, Genesis laser measuring system. I made a pull on the front left shock tower. car measured up perfect.     

[Cuda Cody]

   See what happens when you put it in neutral when the vibration is happening. 

[JS29]

Done that, NO difference. found the car has a non original drive shaft, sent it out to get balanced, A small weight was installed and still no difference. 

[anlauto]

With the front wheel jacked off the ground. Set-up a measuring device, something solid close to the wheel with maybe 1/8" gap or something....then spin the wheel and watch the gap, or even film it with your cell phone...this will tell you if there's any up and down movement or even in and out movement of the whole wheel...at least it's an easy test to eliminate at least one more possibility 

[70 Challenger Lover]

I had this on the RT I just sold but the vibration felt more centered in the car. Since I pressed in new U joints myself, I started there. I got really anal the second time and tried to center it as perfectly as I could in the yolk and thats not easy using a big press. Once I was satisfied it was perfect, I put it back in and the vibration disappeared. The amount it was off side to side could not have been more than 1/32".  It was the same thing though, starts vibrating at 50 and got worse with higher speed.

[JS29]

I had this on the RT I just sold but the vibration felt more centered in the car. Since I pressed in new U joints myself, I started there. I got really anal the second time and tried to center it as perfectly as I could in the yolk and thats not easy using a big press. Once I was satisfied it was perfect, I put it back in and the vibration disappeared. The amount it was off side to side could not have been more than 1/32".  It was the same thing though, starts vibrating at 50 and got worse with higher speed.

Fleet-pride sent the drive shaft out to Syracuse and a new rear U joint was installed, smooth and full range of motion. and balanced. No difference!