Reminis

When driving I can feel a very slight tug to the left every half second or so, not related to speed, it will do this frequency at whatever speed and is no less in wet weather conditions which leads me to believe it is not just tracking.
There is an overall pull to the left all the time, like the tracking is out.
I am getting the tracking done tomorrow along with new tyres to eliminate a dodgy tire.
The pull is ever so slight. In fact the wife doesn't notice it but I know it's there and if I let go of the wheel I have to pull it back within 2secs or so.
And no, it is not related to road surface, it does it everywhere.

I also think that on a left handed corner that it also reverses & twitches to the right slightly, but not as much.

The twitches do not directly effect the direction of the car, I just feel it through the wheel.

From what I have found online some are saying that it might be some valve in the steering rack?
Or
Could it be really bad tracking (positive or negative)?

Please let me know what your opinions are on this, I am keeping an open mind.

Thanks in advance.

Maj. Dundee

Go to an alignment shop and have the entire front end checked followed by a four wheel alignment.

Reminis

Yes, this will be done within the next 12 hrs or so, but I have this funny feeling it's not tracking, the pulsing feels like a warped disc except its the same at any speed which means it's not the discs. Thanks for the input MD.

Maj. Dundee

That's not entirely true. A caliper piston could be stuck open against an already warped rotor.

Reminis

If that were to be true then the pulsing frequency should change with the speed, and it does not, it is constant at any speed.

Maj. Dundee

But you are failing to understand that the pads wear at an angle.

https://www.google.com/search?hl=en&....0.oMnVAfBc7Xs

Reminis

Hi MD, thanks for that.
So are we saying that speed is not a factor to the pulsing if the pads have worn at an uneven level, I would have thought that it would still increase or decrease pulsing with rotation variation?

I can also add that the pads are low, about 5mm left and there is a 1 to 2mm lip on the discs but do appear to have worn evenly.

I didn't experience this on the other ML's when I ran them super low (lower than this) but I understand that each case can be different so am open to accept ideas.

So, lets say that I have fitted new discs & new pads (which I will be doing soon) and I am still getting the pulsing, what could it be next?

Thanks for your input so far.

I will also add an update below on what stage I am at now.

Reminis

Today I swapped out the alloys with the ones from my old ML320.

I fitted new front tyres and had the tracking done.

It no longer pulls to the left, it now runs straight.

However, I am still getting the pulsing but to a lesser effect.

If it was the low brake pad levels then how would the new wheels/tyres reduce the pulsing, I am keen to learn.

Incidentally, I have gone from the standard 17" Merk alloys to 20" alloys. Tyres are 295/45R 20" 114H #XL.

Thanks in advance.

Maj. Dundee

[QUOTE=Reminis;7331098
If it was the low brake pad levels then how would the new wheels/tyres reduce the pulsing, I am keen to learn.

I[/QUOTE]

The tires might have helped a little, but the main correction came from the alignment. But the brakes are still in play.

116Benz

Its not the brakes, the pulse is when your turning the steering wheel just off centre either left or right? And when your driving on a flat, straight stretch of road the steering wheel is centred with the wheels? It could be the power steering pump causing the pulse from the steering angle as a result of the steering wheel being off centre.