Really annoying vibration...

[Iain C]

First I thought it was a wheel bearing, but it's load/power dependant, not speed dependant.  Both front UJ's seem OK, I changed them recently.  Rear UJ sees ok, no obvious wobble.  Going round corners makes no difference.

What can it be? :-k

It's worst at about 2000-3000 revs in 3rd gear, accelerating.  However, you can almost accelerate through it, back off a bit and it goes away.  It's not really a problem at cruise speed at all however.  When it's shaking, the whole vehicle shakes, and if I was to try and say which end it was coming from, I'd say the rear.

Could it be that rubber UJ doughnut thingy?

Vehicle has a 2" lift by the way...any ideas gratefully recieved!

[Range Rover Blues]

Yes it could, also the rubber support bush inside the rear prop as part of the same joint.

Also the top UJ on the front prop typically fails following a lift, it will have worn in with the car at normal height and now that you are pushing it further they tend to wear out.

Also the pulsing caused by the high UJ angle could be a candidate.

As can a missfire, or a broken torque converter driveplate.

[needbeer]

could it be mud on the inside of your rims ?

[Range Rover Blues]

#-o

Obvious.

[Iain C]

Yes it could, also the rubber support bush inside the rear prop as part of the same joint.

Also the top UJ on the front prop typically fails following a lift, it will have worn in with the car at normal height and now that you are pushing it further they tend to wear out.

Also the pulsing caused by the high UJ angle could be a candidate.

As can a missfire, or a broken torque converter driveplate.

Support bush, where does it live?  I changed the rear diff oil seal not so long ago and there was a peg thingy on the flange, is it near there?

High UJ angle...not so sure, it was perfect for a good few thousand miles then suddenly got going...

Top UJ, do you mean gearbox rather than axle end?

Misfire/torque converter, it's a diesel manual so presumably those are both out?

Mud on the rims...nah, would have needed to have gone off road for that and I'm afriad at the mo it's tarmac and towing until I finish the mods and get it dirty over the winter!

[Range Rover Blues]

Support bush lives inside the rpop and fits over that spigot you found.

High UJ angle, well that's exactly what mine did too.  As they run in they inevitably become slightly oval.  If you then start running themn at higher angles you go out of the 'oval zone' and force them to start running in again, they don't seem to like it.

Top UJ, yes the G/Box end, the one doing all the work as the supension goes up and down.  The axle end hardly changes angle at all.

Diesels can missfire too, though you would notice a bit more.  I serioulsy doubt it's as flywheel problem unless your clutch plate has cracked.

Wheel balance, I had a weight come off the day after I'd hasd the wheels balanced.  Modern balance weights are rubbish.

[Iain C]

OK thanks very much for the tips guys, problem is solved.  It was the gearbox end front prop UJ.

Good as it was cheap to fix, bad as it has done under 5000 miles since changing with only very easy off roading!  However if I cast my mind back I have a feeling I may have struggled with that UJ last time and possibly damaged something when I installed it.  The wear was not in the rotational plane, it was along the axis of two opposite sides of the spider, perhaps I did knacker the thrust bearing when I installed it.

I will change the doughnut at some stage though as it's not too clever, some small cracks are appearing, and am I right in saying next time I should put on a TD5 prop which has that funky double UJ thing, more able to cope with a 2" lift?

[Ja1983]

the symptoms and the suspect i have just discovered....

...maybe thats why they are called a discovery?!  :lol:

[Range Rover Blues]

TD5 prop is a good bit of kit for a lifted truck but to get the best from it you should fit castor correction at the same time.