Grinding type noise when turning right

On a 1984 300SD, when turning right, the driver's side front emits a strange grinding type noise. The noise sounds kind of like the tread of the tire is rubbing against something. As far as I can tell, it's not.
The vehicle is most likely in need of replacement motor mounts (noise/vibration when starting and braking in reverse). Could this somehow be related?
I'm thinking it's either somehow related to the motor mounts, or it's a wheel bearing problem. I don't notice any strange noises from the wheel except when turning right, but the vehicle is quite noisey and could make it hard to distinguish.
Thanks.
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Change your motor mounts first. Then fgure out the rest later.
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I had the same symptoms with both my '85 300D and my '82 300CD. The cause turned out to be worn suspension ball joints. Is there uneven tread wear on either of your front tires? If so, the ball joints are the likely culprit.
Geoff
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snipped-for-privacy@u1.netgate.net (Geoff Miller) wrote in

The lower ball joints were replaced (probably around 10,000 miles ago) at the request of a Mercedes mechanic who inspected the front end of the car. He didn't indicate that the uppers needed replacement. At the same time, both the front wheel bearings were replaced. A couple months prior to those repairs, both tie rod ends were replaced on the passenger side.
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i had a similar prob, the flex ehaust mount to the transmission had came off. MB wrote:

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It could be any number of things but I'd be very surprised if changing the motor mounts fixed it. At the age the car is now it probably needs new: tie rods, idler arm and all soft rubber parts in the front suspension renewed. If you plan on keeping the car long to medium term bite the bullet anbd repalce all the wear items. If you just want tofix this noice which frankly is penny wise and pound foolish then you should have a competane mechanic inspect it. It's toug hto diagnose this over the wire modulo a lucky guess.
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I replaced the left and right motor mounts, and the grinding type noise as well as the vibration when the car is in reverse are still present. It also seems as if the grinding noise may be easier to reproduce now, as I don't think I was turning right when I heard it. The vehicle also seems to be just generally rougher running than it used to be.
The work that has been done on the car fairly recently includes new motor mounts, replacing tie rod ends on passenger side, new lower ball joints on both sides, new wheel bearings on both sides, new strut rod bushings on both sides, and a new center carrier and carrier bearing.
I had the front end inspected by a respected Mercedes mechanic perhaps 7,000-10,000 miles ago, and he instructed me to do all the mentioned repairs (with the exception of the tie rod ends and motor mounts).
I'll look into the suggestions already provided, but with this new information, does anyone have any further suggestions?
Thanks
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Check your rims... make sure they are for that car. and look for any grinding marks to fine where is rubbing.
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When were the wheel bearings last replaced?
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I drove the car some more and noticed that the noise seems to have gotten worse after changing the motor mounts. The grinding noise seems to now be present when the wheel is centered or turned to the right (but goes away or at least gets quieter when turning to the left), but only if the car is going above about 45 or 50 mph. This sounds like tires to me, except that the noise shows up when I let my foot off of the pedal, too.
Additionally, the vehicle is loud and vibrates a lot when it is idling. Normally I would think this is motor mounts, but, as I said, they've just been replaced (2 days ago). The vibration gets worse when the vehicle is shifted into reverse and the brake is held in.
The underside of the car was inspected. The exhaust flex mount on the transmission seemed fine, and best I can tell the tie rod ends were fine on the side that hasn't already been replaced. The only thing that was obviously broken or worn was a rubber hanger on the muffler.
I'll look again to see if I see grinding anywhere...
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hi mb, glad you looked at the exhaust flex mount, i swear my 300sd had same symptoms were the same. somehow the flex was vibrating against the steering box frame or whatever... and it sure seemed like 'grinding'... came and went with turning the steering wheel etc. fixed it and poof.. gone.. take another look and see if this still might be the prob somehow. take a big screwdriver and 'tweak' the flex away from the steering, frame, whatever.... MB wrote:

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I would double check the wheel bearing... Wheel bearing will growl when turning...
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I took it to a Mercedes mechanic. He immediately thought that there was a motor mount problem (although they had just been replaced a few days earlier). It turns out that there was something (I think it was part of one of the A/C hoses) pressed against the motor and the chassis, and this seemed to transfer the vibration from the motor to the chassis. This was bent back out of the way and the problem seems to have disappeared for the time being.
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hey, i wasn't far off on my exhaust rubbing the frame.... rest assured you got it, just keep engine stuff from rubbing and no prob.... gary MB wrote:

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