When I get the mustang up to 80 or so it starts making a low pitch vibration noise. It is quite loud and can be felt . I have 3.55 gears so it says I am going 95 or so. It doesnt do it at any lower speeds and it seems to smooth out after about 85. I havnt taken it much if any past that.

Anyone know what could cause this?

 

Weird i get that at low speeds and it starts goin away after like 20. Anyone know a way to get rid of this noise?

 

Tires off balance/out of alignment?

 

Probably the flux-capacitor going. Have it checked before you do any serious time-travel.



That or many factors:

Wheel balance
Driveline balance
Tire pressure
Suspension issues

 

could be linked to bad u joints, or flat spot on the tires.....

 

Or an unbalanced drive shaft...

 

Its vibrating the whole time, its just at that rpm its the worst and can be felt. Called "harmonics" like a tunning fork. Usually something bent will vibrate worse as it goes faster, have a larger area of rpm where it is felt. 5 mph area would point to a U joint, wheel or axle bearing, wheel balance (very small amount), belt separation inside the tire, or possibly a bent or damaged brake drum. Newer fords have indexed driveshafts, meaning it must be put back exactly as it was before removed. Such as a 5.0, bolt the drive shaft back on 90 degrees off and you will have that sort of vibration.

Did you have the gears changed? Any fluids leaking from the backing plates on the rear axel? Uneven wear on your tires? Check the front end to see if there is any play in the steering by having someone move the wheel right and left while you look at the tierod ends, idler arm, and centerlink. There should be no play in the joints, both parts should move exactly together. I dont think that is the problem, but you should check it.

Where does it feel like its coming from? Front? rear? Left? right? Sometimes you can tell where it is vibrating, does the shifter vibrate? Does the steering column? Do you feel it in the seat of you pants?

Oh and why are you driving 80? You live in Montana or something?

 

The U-Joints are brand new. I had to replace the driveshaft when I first bought the car. (The driveshaft the previous owner had in there was to short and barely engaged)

The driveshaft I put in it was off a parts car, so it wasnt in the best cosmetic shape but it seemed solid. It is possible it is out of balance, and I was unaware of a need to index it.

The tires are brand new.

The brake drums on the rear are brand new and the front has disk brakes.

The previous owner had the gears changed. There is a slight leak from the front of the rear end. It is very small, not big enough to drip.

The tires are wearing evenly.

Before I bought the car I checked the front end out and it was all solid.

The vibration is not in the steering wheel at all. It is the strongest in my seat. The vibration feels like it is comming from the rear. It is hard to pin point exacly but it comes in pulses and it seems the sound comes like a wave from the rear of the car. I cant tell if it is left of right.