On my facelifted 2009 ML, someone recently drove it and said that the steering is slow at returning to centre and doesn’t automatically centre and that it’s not the case on other W164’s they’ve driven.

I have always assumed this to be normal for this generation of ML and a characteristic of hydraulic assisted steering but can someone clarify?

I’ve also driven older W210 E Classes with much heavier hydraulic steering and they also don’t return to centre quickly and it is also the same on the W221 S63, but that has heavier steering since it’s an AMG.

My W166 ML550 and G11 750 both have electric assisted power steering and those rotate to centre quickly and artificially, which is normal for electrically assisted steering.

Can someone confirm whether if the W164 steering is indeed supposed to not return to centre similar to EPS? In this case, it does but just slowly and has been like this since day one. Can the centering speed be adjusted in the hydraulic pump somehow? The steering components if I recall correctly have not been replaced nor has MB Service raised any issues regarding the steering parts and feel.

 

I spent a lot of money on the w164 steering wheel.

When I first bought the car, the steering wheel was hard, I installed a Chinese pump, the hardness continued, and the pump that came out was the same brand and model. (The previous owner also placed Chinese part).

Afterwards, I bought a MEYLE brand pump and the steering wheel became softer than before, in fact it was soft for the first 10 days. Then the steering continued to get harder as the day went by.

After 1 year, it has become quite hard to turn.

I replaced the steering box with a Chinese made one. The steering wheel was harder than before, they said it would soften with use. It softened a little after 2 weeks.

And the newly installed steering rack was so hard that it no longer centered the steering wheel, of course it did when turning etc., but it did not center automatically at slow speeds, such as when leaving the parking lot etc.

As a result, my older geniuie steering rack centered very well at the low speeds, the steering wheel must center itself quickly. it may be problem on your steering rack or steering pump or steering universal joint.

 

Thanks for the info.

With that said, it’s felt like this the day it was delivered back in 2009, and all parts are genuine. The service centre hasn’t raised any concern regarding this. Does it mean it should be replaced or were there just tolerance issues out of the factory?