vibration from rear end on a 73 vert

[John J]

I am getting some vbration fron the rear end when I get up to 45 mph. It goes away when I slow down or take my foot off the gas. It seen to come and go but seem to be happening more off now. Any one out there had any of this type of problem. Any ideas whould be great.

John J

 

[wwhite72]

I am always chasing vibrations like that. Shakes, shimmies, pulsing vibrations always seem to start above 45mph. Some suggestions made to me by friends and oher car owners: flat spot on a tire or outta balance, bent wheel, drive shaft outta balance, broken leaf spring, wheel bearing(doesnt matter if you had replaced in the last few thousand miles either, any number of parts in the rear differential...then you might move forward to the tranny for possible sources. I never seem to be able to get everything smoothed out for more than a few thousand miles when something else starts making noise. Then you got yer front tires of course....try wheel bearings first. Its cheapest place to start! Unless the axles have been affected, which was suggested to me as well. And of course check wheel balance.

 

[RacerX]

Swap the tires front to back and see if the vibration moves. Check the drive shaft to see if has any clean areas where it might have lost a weight. Check the u-joints for any looseness (how old are they? - if you don't know - replace them)

Had any work been done to the car recently? Did the problem just start all of a sudden?

 

[mycoses]

had similar problem. here is my experience. third member causes noise not vibration. take out axles and check bearings and have machine shop spin on a lathe to check straightness of axles. replace U joint they are cheap. take drive shaft to shop to check balance and correct if necessary. check trans mount to see if rubber has collapsed and are getting metal contact between mount and cross bar. another issue is pinion angle which is a whole one page description so try other things first.

 

[JimNiki]

Next time you go for a drive, on a straight road with no-one behind you, I'd put it in neutral or turn the engine off.

It may shed some light or at least you may be able to hear some tell tale noises... cost you nothing....

 

[caspianwendell]

As stated earlier, check u joints

 

[Bill73Ragtop]

As stated earlier, check u joints

Ditto. First thing to check. If you have ever lost a drive shaft due to rear u joint failure in a convertible you will never forget the experience. You run the risk of extensive sheet metal damage since The tunnel support plate prevents it from dropping down and away -- it continues to spin and beat the hell out of the sheet metal.

As noted previously, if U-joints are good (and installed into the yoke properly) move on to axle bearings.

 

[Tubo]

I've had a simular issue. When the vibration followed the third member from one Stang to another, the chunk itself was identified as the source. Turns out, the vibration was coming from the pinion bearing. I'd been living with that vibration for years.

 

[John J]

Thanks for the feed back everyone. I am getting ready to store the car for the winter and will put to check out the U joints on my to do list for the spring.

John J

 

[Mustang Dynasty]

same problem and found the same-bearings. Small thing if it is caught in time. If everything checks out ok...i see you found it in time.thats good.

 

[phagan63]

I have/had the same problem recently as well. Only my "shimmy" felt like it was coming from the front of the car. On the sage advice of some of the forum members, I started with having the wheels and tires rebalanced. Even though they were new wheels and tires just recently installed, the tire shop showed me that all of them were out of balance to some degree. After the balancing was complete, it definitely improved the vibration condition but there is still a little bit there ... just not as intense as before. Next step for me is the idler arm because it appears to be worn (visible torn boot).

So ... After doing all the visual inspections described by the other replies, if you can't find anything obvious, definitely start with a rebalance of your wheels and tires.

 

[Manu Mach1]

Hi,

If you have recently removed the shaft out, disconnected from the yoke, you need to reconnect like it was (the yoke and the driveshaft should be marked) if not you loose the balance and this can cause vibrations.

Just an idea. Hope it's clear.

 

[droptop73]

Here's what I've been through chasing a vibration at 70 or so. U-joints, re-balanced tires, tightened rear u-bolts, replaced trans mount, wedge shims to adjust the pinion angle. All of these helped and the vibration has been minimized.

 

[judge]

I'd have someone drive it while you follow. Observe all four wheels for hopping or shaking. Could be rust on drum at wheel mounting position. CB bent axle from previous accident.

 

[Mustang Dynasty]

once you straighten out your....their is nice universal traction -chrome-bars that attach to leafs that completley stops hopping and significantly improve take offs/re: increase rate of to 60+mph.