Disco Pulling to the left

[Guest DiscoTD4]

Hi - my TD300 seems to be constantly pulling to the left even on nice flat roads. It has newish matched set of tyres all round at correct pressures. Checking the toe in it seemed to be slighly toe in, so I have adjusted it to the std toe out and still not difference.

No obvious steering affects when braking or accelerating.

I don't believe there are any other adjustments possible, so may be looking at worn bushes etc ?

Otherwise plucking at straws here, but the tyres are Pirelli Scorpion ST and whilst there are no obvious rotation arrows, the side wall does have chevrons all the way round, are these supposed to be teh rotational marking - only the tyres have all been fitted the same way round, so one side the chevrons face the wrong way.

This is the tread pattern, which is not symmetrical

Cheers

[freeagent]

might be a wheel bearing... or a sticking brake caliper.

[Frode Haaland]

What has happened recently/which repairs have You been through?

Assume You have checked draglink and track rod for being bent, and calipers and bearings. Then remove steering damper to check if it has any effect.

Then check steering box for beeing at point of zero backlash (i.e. drop arm point dead ahead when front wheels are pointing dead ahead - if not: You will have steering servo assistance pulling steering rods).

[Guest DiscoTD4]

What has happened recently/which repairs have You been through?

Assume You have checked draglink and track rod for being bent, and calipers and bearings. Then remove steering damper to check if it has any effect.

Then check steering box for beeing at point of zero backlash (i.e. drop arm point dead ahead when front wheels are pointing dead ahead - if not: You will have steering servo assistance pulling steering rods).

The problem has been with me since obtaining the car couple of months ago. Wheel bearings and brakes all check out fine with no play or sticking calipers etc.

All connecting rods look fine, tracking has been adjusted for toe in, toe out and zero and makes no difference. Have swapped front tyres around and again no difference.

From what you are saying it appears that the servo assistance has a self centering affect in any position other than straight ahead. TBH I always thought it was neutral with no steering input and only applys assistance when the steering is moved in either direction ? If so this may well be the cause of the problem

[Frode Haaland]

You're correct...if the drag-link has correctly set length. If it is too short/long it will pull one side or the other. Think of it this way:

When You turn the steering wheel beyond dead ahead, You want servo assistance to turn the wheels.

If the draglink/steering box is incorrectly set up, i.e. the drop arm points this or that direction, it is efficiently the same as if You have already started turning the steering wheel, wanting servo assistance.

A first chk is then to measure the length of draglink (cfr manual for this).

To chk more thoroghly: If I remember correctly (chk manual) You can insert a pin to lock the steering box dead ahead. If the vehicle then turns one way or another, the drag link needs adjusting longer or shorter.

Then You will come in what's known as zero backlash position, and the vehicle stops pulling left or right.

But: First of all: Some claim gas charged steering dampers to pull on the steering, and as this is two nuts only, chk that first.

Happy spannering!