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After 95k miles and plenty of squeaking, I finally changed out the upper and lower control arm bushes as well as the sway bar bushes and links on my 2009 ML550. This has made a huge difference to the way it handles and cushions you from the road. I wish I'd done it earlier. It almost feels like a new car again.
About 6 hours labour at an Indy shop who did it all, with my parts. Arms were retained and just the bushes changed. Ball joints tested and were fine. Parts available from FCP Euro or there's also a kit with the arms to buy, but it doesn't include the sway bar links & bushes which you'll have to add. Note, that the upper arm ball joint can't be changed unless you buy a complete arm, so keep that in mind. If your putting this off as I did, don't. I suspect it was the lower arm bushes and sway bar work that made 90% of the difference. You'll be more than happy with the outcome and not just the lack of squeaking.
After 95k miles and plenty of squeaking, I finally changed out the upper and lower control arm bushes as well as the sway bar bushes and links on my 2009 ML550. This has made a huge difference to the way it handles and cushions you from the road. I wish I'd done it earlier. It almost feels like a new car again.
About 6 hours labour at an Indy shop who did it all, with my parts. Arms were retained and just the bushes changed. Ball joints tested and were fine. Parts available from FCP Euro or there's also a kit with the arms to buy, but it doesn't include the sway bar links & bushes which you'll have to add. Note, that the upper arm ball joint can't be changed unless you buy a complete arm, so keep that in mind. If your putting this off as I did, don't. I suspect it was the lower arm bushes and sway bar work that made 90% of the difference. You'll be more than happy with the outcome and not just the lack of squeaking.
I did the same thing on my 08 GL at around ~200K miles. It really does make a difference if they're in bad shape - no more noise and it drives much better. The bushings on my upper arms in particular were in bad shape and making noise. Fortunately the bushings on my 90K mile ML are still in good shape so I don't need to repeat the job yet. I did the mechanical work myself and had a machine shop press the bushings in/out of the lower arms. The shop said they were a bear to do, and the cost of the bushings + the labor cost from the machine shop ended up being a significant % of the cost of just buying new lower arms from FCP Euro although the new arms don't include a ball joint, so you'd have to install new ones (mine were actually in pretty good shape but I did them anyway because the arms were off and I had the parts on hand).
I did the same thing on my 08 GL at around ~200K miles. It really does make a difference if they're in bad shape - no more noise and it drives much better. The bushings on my upper arms in particular were in bad shape and making noise. Fortunately the bushings on my 90K mile ML are still in good shape so I don't need to repeat the job yet. I did the mechanical work myself and had a machine shop press the bushings in/out of the lower arms. The shop said they were a bear to do, and the cost of the bushings + the labor cost from the machine shop ended up being a significant % of the cost of just buying new lower arms from FCP Euro although the new arms don't include a ball joint, so you'd have to install new ones (mine were actually in pretty good shape but I did them anyway because the arms were off and I had the parts on hand).
Would you say that this job can't be done without the press?
Would you say that this job can't be done without the press?
I wouldn't try it for the lower control arm rear bushing without a heavy duty mechanical press. Bush removal tools are a waste of time. We had to cut out the rear bush and it was a nightmare.
Upper arms are easy to replace the bushes and can be done with a press or a bush removal tool.
I have a question on replacing the bushings. The bushing with the aluminum housing that bolts on the end of the lower control arm… any issues replacing that one? I was going to try and do just that one or should I pull it down and replace all 3? The aluminum housed one is definitely bad on my GL550 thanks for any help and direction . Bill
Bill, the difficult one is the round one that needs to be pushed on with a press and its the rear one on the control arm. It was a nightmare to get out. If I had to do it again, Id buy the lemforder control arm and make life easy. see pic attached ive highlighted the difficult one. If it were me, I dont have a hoist, I wouldn't want to have to do it again so even if the others look OK, I'd still be buying the whole arm with bushes installed and doing it that way. Whatever you do, don't buy the Chinese parts. Lemforder sell both the arms or bushes, and theyre as good as you'll find. FCP Euro sell them and have the lifetime guarantee.
Last edited by BlackML550; Sep 16, 2023 at 04:15 AM.
Thank you for the quick response. I do have a lift in my building and will be using it for sure. The back bushing with the aluminum case is the one and only one I am replacing . Do you know if Vaico brand is any good? thanks again and I do believe we might have finally found the noise today. Right behind the lower control arm rear bushing is a body mount rubber and it is rusted and ugly . Trying to find a part number now thanks Bill
I'd go the Lemforder who are also OE suppliers to MB. I wouldn't imagine the cost difference is worth it given the amount of effort you'll go to. Vaico make parts for just about everything so Id be surprised if their quality was better than Lemforder.
UPDATE - After 18 months I'm getting a constant knocking in the right had front. Thinking this was the upper ball joint, I bought a new upper control arm. I pulled the old one out which I had changed the bushings on last year. To my surprise, as I pulled the arm off, one of the bushings just fell out, noting that these needed to be pressed in to begin with.
It seems that I'd overtightened the bolts on the bushing, not allowing it to move as the control arm moved. The bushing was then rubbing and evetually spinning against the inner sleeve of the control arm, wearing it out to the point that the bushing just fell out.
61Nm is the tightening torque it seems. Photos below. Bushing with worn metal outer Control Arm worn on inner sleeve Loose bushing that fell out
Last edited by BlackML550; Jan 22, 2024 at 02:36 AM.
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