evan8

Hi my 2012 GL450 is making a continuous rubber rubbing/grinding sound when turning steering wheel, left or right. The sound is coming behind the steering wheel and around under the front windshield area, as you can hear it even not moving and then steer. I just had steering pump and rack/pinion replaced yesterday at dealer and now it is making this sound. Not sure if related or the rack is connected to the steering wheel. Could anyone advise on what could cause this and if it needs to be looked at please? Thank you!

CharlzO

Hard to say exactly what it could be, I'm not familiar with them yet. However, if it started after they serviced it, my first stop would be right back to the dealer that worked on it, and have them look at it. Seems a little more than a coincidence if they fixed it, and then it started making the sound.

TX07GL450

Most likely tie rod end links. Is it kind a squeaky noise (rubber on rubber squeak) as you turn the steering wheel left and right? They can get this way, when popped with a fork while doing some other work on steering system or knuckle.

evan8

Is this tie rod end links a mechanical issue that can easily fixed or affect steering column and need to replace the column? BTW, how does the steering pinion connect to the steering column and wheel? I am not sure the work on the pinion would somehow caused this. Thank you!

TX07GL450

It is just a hypothesis though. Best bet will be to take it back to dealer and say that it happened after the repair work. Then you can see what they say.
the sound could also be coming from new steering rack / pinion

outer tied rod end is an easy replaceable mechanical part, if it is the culprit.
there is one on each side and both need to be taken off and put back in in order to replace steering rack. they are number 3 second figure in the link below. even though they are far, the sound transmits and feels like coming from steering wheel.

https://www.genuinemercedesparts.com...d-linkage-scat

evan8

Thank you TX07GL450 for your help! I will mention it for sure. Could you let me know how is the pinion in relation to the steering wheel. It shows it laying across maybe connected to the tires, but I thought it connects to the steering wheel at a diagonal upward angel. Sorry about my ignorance

TX07GL450

so basically part number 1 (steering column) in following figure
https://www.genuinemercedesparts.com...ng-column-scat
connects to part number 7 (steering coupling) in following link (2nd figure)
https://www.genuinemercedesparts.com...d-linkage-scat
I hope it explains.

I have not worked on my gl450 steering system YET, but I would guess that steering column doesn't need to be taken off in order to replace rack and pinion or steering pump.

I had following noise on my civic years ago. Dealer wanted to change tie rod end links but I had decided to sell the car



You can try following fix. For me it didn't work back then

evan8

Thank you! It makes sense to me now. So the pinion actually connects to the wheel/tires. And via inner tie rod connects to steering column. Since I also had to replace my suspension air pump, my dealer mechanic mentioned that maybe the extra air pushed the suspension/pinion such that steering is making that noise now. Not sure if that is valid or not; he says it is no safety issue.
I did see these videos but on GL450 I didn't see how I can remove that bottom cover...
I am taking the car to the dealer like you suggested next week to have this looked at. Thank you so much for your suggestions! If there is anything that you would like to share on the squeek, I love to hear! Thanks again!

TX07GL450

via steering coupling/linkage (not inner tie rod)

No! that can't happen. suspension air lines and rack / pinion has no connection

Suspension air system deals with ride height and comfort cushioning
steering mechanism deals with turning wheels left / right

yes, that is correct but hell of annoyance. They gotta fix it.

evan8

Now I understand much better! Thank you so much for your help. I hope you have a great weekend! I appreciate your time!