W208 CLK front left losing grip on slow turns

[hooblah]

I had the drag link replaced and an alignment done a couple of months ago. Then this issue cropped up within the past month... The front left loses grip on slow right handers and almost ploughs straight on when it's wet. It makes a noise as though the tyre is being dragged.
I thought it might be related to worn bushes, so I've just had the upper arms and ball joints replaced, and powerflex bushes fitted to the lower arms. It hasn't solved the problem.

Wiggling the steering quickly produces a knocking noise. The steering box bolts have been tightened, and everything that could wear has now been replaced.
On jacking the car up it does appear that there is play in the steering. But it's not the drag link. Theres nothing left to replace now other than the steering box.

My hypothesis is that the play in the steering box is causing ackermann to be thrown off. But what do I know...

 

[Wighty]

Crappy worn tyres , low pressure ?

 

[hooblah]

Tyres are Uniroyal rainsports and aren't worn enough to be considering them to be the cause. However I'm not going to rule it out just yet.

 

[Uncle Benz]

Have a look at your steering idler. Common for this sort of thing

 

[hooblah]

Thanks, I'll check that out.

 

[hooblah]

Ok so it's both tyres now scrubbing at low speed manoeuvres. It's definitely related to suspension geometry. Camber looks fine and I doubt that would be the cause. Could it be toe in/out?

 

[Uncle Benz]

If it’s related to cold weather have a look at the age of your tyres. The rubber gets hard and in the cold they like to make a noise. You mentioned that you thought steering box wear could affect the ackerman angle. This is not true. Ackerman, or toe-out-on-turns, is the relationship between each of the front wheels. On a steering box system, the box is a single input. It has no bearing on the relationship between one wheel and the other. Every other component except the steering box does influence the ackerman. Did you have a look at the idler? A geometry session is a waste of time and money unless you know every other component is good

 

[Uncle Benz]

Who did the front wheel alignment check after the central drag link was replaced?
Steering boxes do wear, but you’ll most likely notice a wandering and need for constant correction on a straight piece of road.

 

[hooblah]

Thanks for the detailed response.
The lower bushes were replaced with powerflex parts. The new bolts were fixed at the inner most position to decrease camber. I reckon this has made it toe in further. The upper arms were replaced at the same time. I noticed the front end hadn't settled after a few days of driving around. Yesterday I asked the garage to loosen off the upper arm bolts to allow it to settle. This has improved things a fair bit, but still not enough.
I haven't had a look at the idler yet. I'll get an alignment done tomorrow and then worry about that.

 

[Uncle Benz]

Fitting the adjuster bolts will certainly have an effect on the toe. It might be an idea to actually measure the camber rather than just setting the bolts to their furthest extreme.

 

[hooblah]

Alignment done. It has helped to some extent, but not fully. I can't help but think everyone that works in a tyre place (no matter how big and nice it is) is a moron.

Probably unrelated, but I've got a thudding sound from the front left when when driving at speed over expansion gaps (think M25 concrete section on the west side).
I'm going to replace the steering idler and then replace shocks and springs all round, then get it aligned again.

 

[alexanderfoti]

We can align these old steering box MB s well, but depending on where you are Wheels In Motion will sort the lot out do your aswell (without being morons)

 

[mattkh]

....... but I've got a thudding sound from the front left when when driving at speed over expansion gaps

Are the two front tyres exactly the same in spec. and wear and air pressure,,???

 

[hooblah]

Are the two front tyres exactly the same in spec. and wear and air pressure,,???

Yes.

 

[zedmeister]

Are the wheel bearings okay? Just a shot in the dark.

 

[zedmeister]

Could it be anything at the rear pushing or dragging causing the front to do weird things? I have had horrible handing at some point in the past of my 16 years of w208 ownership but I believe it was all tyre related. No problems now. Also wrong springs (front or rear) can cause handling issues. I know I have been no help whatsoever...

 

[hooblah]

Wheel bearings are fine. There are no problems with the rear end. Thanks for trying to help at least.

 

[mattkh]

How about two bags of sand in the front passenger footwell and testing.

 

[hooblah]

I'm still having this issue and I just can't think what's causing it. The steering becomes light and void of feel when I turn right at slow speed, e.g. driving around a car park. Almost as if something was loose.

I've recently had an alignment. The front right behaves normally. There's nothing on the rear end affecting it. The tyres may be nearing replacement, but they're not bald. There seems to be a bit of play in the steering linkage, but seeing as it's recently been replaced, I'm going to say it's coming from the steering box.

What could cause an outside front tyre to stop gripping mid turn? A drastic camber change? A difference in toe? Something else?

 

[zedmeister]

What's the date code on the tyres? They could be just old.