Hi,

picked up my 'new' 2006 HSE 4.4v8 RRS and a happy bunny

Got a random steering shake for which I see no pattern although it seems to be moreso at 45mph +

I do have aftermarket 22" 's on with what appear to be some rubbish Chinese brand tyre (Sumintra??).

My pressures were 39psi front and 30psi rear but I changed these to 35 front and 36 rear - car feels heavier but from reading the threads on here and elsewhere the pressures should be higher (and the door card agrees). Despite the pressure change it's made no improvement, although in my view the car feels better and less 'skittish'.

Any suggestions?

Thanks!

Start by putting decent rubber on the wheels. Chinese ditch finders have no place on a high performance 2.5 tonne 4x4.

Next, did your vehicle come out of the factory with 20 inch rims fitted? Be worth checking that you have the damped steering rack that was introduced to deal with bigger rims. This became a standard fit at some point in 2006/7 I think.
See here: http://www.rrsport.co.uk/forum/viewtopic.php?t=264

Also, are the rims from a decent manufacturer? Are they correctly load rated (applies to the tyres too) and are they true? 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Try 40 front 42 back transformed my ride  Current 55 reg 2.7tdvs with Hst extras

Will do that tonight .... you didn't find it too light?

Coming from a Vogue I found that to 'feel' a lot more planted.

Thanks for the tip!

Could also be worn bushings in track rod arms ... Get play checked ....I think these are fairly cheap and simple to replace - well at least aftermarket ....

40F and 42R made a marked difference - far less shimmy

Will get the wheels force balanced too and see if that helps!

Thanks guys .... will keep an ear out for anything else it could be.

Took it for a good drive today and the shaking is there from about 50-60mph.... definitely not helped by road surface. I find that on a newly raid road it's non-existant.

Probably the mass of the wheels is such that at a certain road speed the small changes become more pronounced and turn into shakes?

Need to check which steering rack I have too later