Help major vibration no one can identify

Gentlemen good afternoon have just returned from my local private Landy specialist and am now totally at a loss.
The problem is a vibration which kicks in at about 50 mph and again at 95 mph but not all the time totally at random.
We cannot find out why jobs done so far wheels balanced and finally changed - tracking done 3 times - track rod ends replced - steering damper replaced - swivels done - wheel bearings done - new brake pads and discs - all fluids in gearbox transfer box and diffs replaced (that was a long shot) - new suspension bags and new shocks .
The vibration can dissappear for as much as a week at a time it is not constant it also shows up or not under heavy braking you can feel it in the whole car but mostly through the steering any ideas welcomed Sorry meant to mention it is a 1998 4.6 P38 HSE

Can't remember where or even how but I'm sure I've heard that ABS can produce a similar kind of vibration. Does this ring any bells for anyone else??

Do you have ABS?

Yes it does have ABS and someone else mentioned that will try and isolate it and see what happens.

Hi
Have you checked the universal joints on the props?
Make sure handbrake is OFF before checking

Check your prop shafts are tight and there is no backlash when you twist the shaft.
Check that the rubber donut joint on the prop shaft is not split.
Check your engine and gearbox mounts for wear and movement.
Check that the drop arm ball joint is not worn and the bolt is tight on the steering box.
Have you got large wheels and low profile tyres fitted?
Have you got spacers fitted to the wheels?
Have you had the hubs replaced as you dont/can't do the bearings without replacing the hubs.
Check the steering arm joints in the engine bay for splits on the rubber joint and wear in the universal joints.

Does a P38 have an Harmonic damper? Might be worth thinking about, then again I could be talking out the back of me ead.

classic kev said:

Does a P38 have an Harmonic damper? Might be worth thinking about, then again I could be talking out the back of me ead.

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Have look at this - Range Rover P38/4.0/4.6 Common Problems and Fixes

The props have all been checked ,engine and all mounts were replaced 5000 miles ago and all look good ,steering box checks , the symptoms are the same with two different sets of wheels as for the hubs I replaced the wheel bearings without changing the hubs - bit of a pig of a job but has been running ok for 15k miles since they were changed.- could it be the suspension bags somewhere in my old brain I recollect someone having a resonnance prob with two different types of bag??
We really have tried a lot even a Landrover techie from main dealer is a friend of the bloke who owns the garage but any suggestions welcomed

Hi - i'm having a similar issue with my RRS - what was the solution??

@sandyt not been on since last August.

Sport is akin to the Disco 3/4 so bears no relation to a P38.

RRS/Disco suffers from front wishbone bush wear, and problems are exacerbated by humungous rims.

I'd start by checking tyre condition and correct rotational fitment, then move on to tracking.

UJ's on the props are on their way out. I had this on a 6Ltr Dodge van in the states. Took me ages to realise it was the UJ's failing.

Try radius arm bushes these wear quickly( don't swap to poly's). Wheel bearings I think these can be tricky to detect wear as a. There real heavy duty and b.the wheels are really heavy. Take the wheels off and check for silver paste around hubs. Spigot rings missing ( although this is not a subtle shake!) Ball joints often missed because of changing difficulty. Have you distorted the hubs when pressing new bearings in?

Do you have L322 wheels fitted, if so are they fitted with spigots?

I think gold rover had vibration and was traced to a faulty injector

sandyt said:

The problem is a vibration which kicks in at about 50 mph and again at 95 mph but not all the time totally at random.

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what is the surface like on the autobahn

what tyres do you have fitted how worn are they ? the roads are pretty cack in our part of the country. i was getting vibration on mine on some roads and my Pirellis were wearing down. Uniroyal rainsport 3's now and all good on the roads that were giving vibration i also run at 28 PSi all round and get dead even wear across the face. higher pressure does transmit more road surface

@aca01mjf people are already trying to help you over on the thread you started. It would probably help them and you if you stuck with that thread, rather than resurrecting 10yr old threads!
https://www.landyzone.co.uk/land-rover/vibration-under-braking-that-isnt-warped-discs.328822/