rear-end wobble

[plugger]

Getting a serious vibration on the back end about 40 - 50 mph in top when under power. When I back off she runs smoothly, it's the same in every gear at about the same revs (Oh for a rev counter!) but only when the power is on.
Any ideas?

[V8MoneyPit]

You're not getting strange squeeking noises at the same time as your rear end vibrates, are you?  :shock: :lol: If so, I'd look at your joints..... UJ's.

[plugger]

No, no squeaks, I did wonder if it could be U/Js but wouldn't they be a problem at all speeds?
Coming to a halt there is a slight knocking from the rear as well,  feels as if something's trying to push from behind - weird sensation!

[tack43]

A frame ball joint?

[Saffy]

Your going to have to jack it up and inspect for anything obvious with suspension, give each wheel a spin check for binding, bearing play, differential making nasty noises,  check them UJ's they will drone, vibrate and bind, check transmission hand brake for binding.

betting on UJ's

[Range Rover Blues]

Same vibration at about the same engine speed in any gear? that sounds like a misfire.

Of course the obvious is the propshaft/handbrake area and you must ensure these are sound before going any further.

[kevinf]

  A frame ball joint,worn half shaft drive flanges,worn or poor quality trailing arm bushes one of these or a comgbination of all of them?

[plugger]

Same vibration at about the same engine speed in any gear? that sounds like a misfire.

Of course the obvious is the propshaft/handbrake area and you must ensure these are sound before going any further.

Yes, I thought exactly the same but there's no vibration from the front or through the gearstick suggesting it's not misfiring, seems the prop/ uj's are the first things to investigate.
Thanks for the feedback

[plugger]

  A frame ball joint,worn half shaft drive flanges,worn or poor quality trailing arm bushes one of these or a comgbination of all of them?

Thanks Kevin

Looks like a weekend covered in rust dust for me then!

Bob

[sv130]

  "Coming to a halt there is a slight knocking from the rear as well,  feels as if something's trying to push from behind - weird sensation!"

  Just make a quick check that your center diff isnt locked in place mate, forget about the little light being off and jack the car up to do it.


 Gaz

[davidlandy]

mine did that and it was the A frame ball joint on the top of the axle worn out

[extreme90]

it'll be the a-frame ball joint as mentioned
a good way to test is have some one sat in the truck letting the clutch out a little in 1st low, with there foot on the brake.
you will see the nose of the diff pinion rise and fall which emitts the vibration due to a different prop angle.
the nock will be the ball joint moving around under load and going onto over run.