"Tramlining"

[kns]

I run a '65 230sl and experience just a little 'tramlining' - the tendency of the car on occasion to follow its own line and stubbornly ignore subtle steering adjustments. I think that the camber/castor adjustments are fairly good (although confirmation of the optimum set-up would be welcome), so I am left to wonder whether I should replace the suspension bushes or look for a more sinister cause.
One possibility is the freeplay in the front kingpin connection - if I push on the top of the wheel, it 'gives' a couple of centimetres (3/4"), which I feel it should not. I am hoping that does not signal a need to changeout the kingpins, as I suspect that an entire assembly will be hard to source [in Australia] and/or uncomfortably expensive.

Any thoughts will be much appreciated.

kns.

[rwmastel]

I believe the wheel should not give at all.  Others with real suspension / steering experience can elaborate on the details.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[George Davis]

kns,

I don't know how much your suspension is involved, but tire sidewall stiffness has a lot to do with tramlining.  Wide, low profile tires are really susceptible to this.  Sidewall stiffness is also affected by inflation pressure.  I was previously running tire pressures of 28 psi F/30 psi rear.  At Albert's suggestion, I upped the rear pressure to 35 psi, and immediately noticed an increased tendency to tramline.

George Davis
'69 280 SL Euro manual