Had exactly the same on a Disco. New steering damper and wheel balance sorted it.

RSFH said:

As you seem to have eliminated any slop in the steering system & judging by the severity of the shake, I would strongly suspect a resonance issue. You have a number of number of non standard/original parts fitted and this combination could produce a critical frequency resonance. Therefore to eliminate this as a possibility, you will need to change out one of these elements. The wheels are the most obvious and easy to change, so try a balanced set of original wheels and see how that goes. If you do not have any to hand, is there another RR P38 owner / dealer/ specialist nearby that maybe willing to lend a set for a brief trial?
Best of luck sit looks quite frightening!

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I like your thinking, i'll try and source some orignal wheels from somewhere. I'm also gonna go have the tracking done at another place tonight just to double check it is correct.

lezbrucelee said:

I like your thinking, i'll try and source some orignal wheels from somewhere. I'm also gonna go have the tracking done at another place tonight just to double check it is correct.

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I would strongly suggest you take the car and get the wheels properly dynamically balanced. If they are not propely balance dynamically the camber angle and castor angle they run at causes a wobble to develop side to side as the heavier inside or outside of the tyre changes direction as the wheel turns. This together with a weak damper can cause this problem.

wammers said:

I would strongly suggest you take the car and get the wheels properly dynamically balanced. If they are not propely balance dynamically the camber angle and castor angle they run at causes a wobble to develop side to side as the heavier inside or outside of the tyre changes direction as the wheel turns. This together with a weak damper can cause this problem.

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do u know anywhere that does dynamic balancing in kent? i assume kwik **** cant do it or u just mean a full 4wheel alinement?

lezbrucelee said:

do u know anywhere that does dynamic balancing in kent? i assume kwik **** cant do it or u just mean a full 4wheel alinement?

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All garages should do dynamic balance it's just whether it's done correctly or not. I have had same wheel back several times before it was balanced correctly. Alloys normally have stick on weights, if you have lost a couple off both sides and through turning the steering both heavy spots have coincided together with a weak damper maybe that is your problem. As i said had this on a Disco slight wobble through 50-60 mph then ok. But on the overrun around 55mph but not every time a real tank slapper. Or if you tried to drive around 50-60 mph a wobble started. Wheel balance and new damper cured it. I take it you have checked all steering joints. Play in them may not cause it but will certainly add to any wheel wobble. What speed does you problem start, lots of vehicles seem to have a critical area around 50-60 mph? If yours is a lot less than that it can really only be a very out of balance problem.

:welcome2:
Had that tracking done on the car couple of days ago, it was out by 0.5 on one side and 1 to the rear, had it all put to manufact spec and been out and been out n about with it.

The servarity (ABC???) of it has gone away now raise:

I can now drive it normal until i hit a large bump with the offside front and it starts to shudder, nowhere near as bad. It has too be something on that wheel.
I'm thinking it has to be a ball joint or where the hub bolts to the ball joint. I couldn't feel any play when i checked it but it has be be there.
I looked into changing them but looks a bit serious, appears you need specialist tools that i dont have, and dont wanna buy

Is there anyway i can do this myself without the specailist tools or it there any adjustment in the joint?

had the ball joints replaced and she drives beautifully now, thanks to everyone that help with the problems