EllisM

As most say, I’m new to posting here so I apologise if this has been covered a hundred times. I have trawled and cannot find the same problem being discussed but by all means direct me if I have missed it.
Here goes, 2008 GL 420 cdi with 155k miles always serviced and any works needed carried out by an indie.
Problem; stiff steering.
So far have changed fluid, replaced the small variable speed sensor ( genuine mb part).
No difference so I am happy to change the power steering pump and reservoir but Im not completely convinced it’s that.
After being sat for a couple of days the steering is perfect, for about 2 minutes. Raising the revs makes no difference. The same at all speeds. No noise from the pump or gunk in the reservoir. With my car being fairly old with quite a few clever bits on it I have read many forum pieces here which have helped immensely. I thank you in advance if you have taken the time to read and respond to this. Cheers.

MJ50

moved to X164 forum...

DennisG01

Maybe someone can confirm/deny if I'm on the right track here...

-- How does it steer with the engine off and the front wheels off the ground? I would "think" that would give info as to whether or not the rack is binding up.

-- I have an older BMW - steering has been stiff for a few years - never got worse - but I got tired of it - didn't have time to mess with it myself once I got tired of it -- dropped it off at a local shop and it turned out to be the pump.

Miguk_Saram

Stiff steering is almost always the pump. Especially if you've already check the fluid.

BlackML550

At the end of the steering column there is a universal joint where it connects with the steering rack that commonly seizes. This happened to mine. It was only stiff for 90 degress but it had seized. Check that before you go replacing expensive parts. See if some wd40 loosens it, but it may not.

EllisM

much appreciated, I will definitely try the lubrication route first. I will keep all posted as to the result.
All input appreciated
cheers