Planetary Gear Set
How long am I ok to drive it in this condition while I decide what I want to do? The vibration isn't terrible, and it's only when making low speed turns, and starts going away the warmer it gets.





How long am I ok to drive it in this condition while I decide what I want to do? The vibration isn't terrible, and it's only when making low speed turns, and starts going away the warmer it gets.
Vibration can be caused by the locking disk "stick-slip" condition when you make sharp turns and the disk must let front and rear axles rotate different speeds.
The center differential lock in these cars to my understanding is a "simple" spring loaded clutch that will allow movement under certain torque conditions between the axles. Because there is always some "spring" present in these systems you can get this stick-slip condition in the locking disk that cause vibrations.
Years ago, in this forum, there were people telling how they fixed this issue by jacking one wheel up and running the car with gear ON for a little bit to "clean" the differential locking clutch disk. Some people claimed this also worked.
I would try something like this myself first before letting someone do fix that may have nothing to do with your problem. If you run one wheel up, you can also hear if you really have the planetary gear problem as only one wheel up and turning will make the planetary gears rotate and they usually make whining noise if the bearing failure is present with them.
Vibration can be caused by the locking disk "stick-slip" condition when you make sharp turns and the disk must let front and rear axles rotate different speeds.
The center differential lock in these cars to my understanding is a "simple" spring loaded clutch that will allow movement under certain torque conditions between the axles. Because there is always some "spring" present in these systems you can get this stick-slip condition in the locking disk that cause vibrations.
Years ago, in this forum, there were people telling how they fixed this issue by jacking one wheel up and running the car with gear ON for a little bit to "clean" the differential locking clutch disk. Some people claimed this also worked.
I would try something like this myself first before letting someone do fix that may have nothing to do with your problem. If you run one wheel up, you can also hear if you really have the planetary gear problem as only one wheel up and turning will make the planetary gears rotate and they usually make whining noise if the bearing failure is present with them.
The best way to describe it is that it feels like making a turn in a truck with 4x4 engaged.
Last edited by Andre91; Mar 18, 2023 at 12:13 PM.




The best way to describe it is that it feels like making a turn in a truck with 4x4 engaged.
You could go find a big empty parking lot where you can drive circles with different radius. This should not damage the car as it was designed to be driven with wheels turned in any road surface. This would be doing kind of the "wheels up" test in a legal way. If it is about the disk surface needing some "cleaning" you should see the condition get better. If not, then it may well be the problem with the planetary bearing.
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I do very little highway driving, I occasionally go for a 45 minute-hour drive on a nice day, maybe once a month, but other than that all of my driving is in the city. Could it just be a case of needing to get the transfer case up to temp and give it enough time to clean any buildup off the clutches?
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I do very little highway driving, I occasionally go for a 45 minute-hour drive on a nice day, maybe once a month, but other than that all of my driving is in the city. Could it just be a case of needing to get the transfer case up to temp and give it enough time to clean any buildup off the clutches?
There are people recommending center differential clutch disc cleaning by jacking one wheel up and running the car on gear for 10 - 20 seconds. This procedure is not recommended by MB but that would be the first thing I would do if I had a 4Matic and it would start acting up like that.
If the problem is with the bearing that has been found to be an issue in many cars this procedure does not make any worse but if it is about clutch disk surface condition it can be a big help.
There are people recommending center differential clutch disc cleaning by jacking one wheel up and running the car on gear for 10 - 20 seconds. This procedure is not recommended by MB but that would be the first thing I would do if I had a 4Matic and it would start acting up like that.
If the problem is with the bearing that has been found to be an issue in many cars this procedure does not make any worse but if it is about clutch disk surface condition it can be a big help.
Last edited by thewheelm4n; May 30, 2025 at 12:03 PM.


I do very little highway driving, I occasionally go for a 45 minute-hour drive on a nice day, maybe once a month, but other than that all of my driving is in the city. Could it just be a case of needing to get the transfer case up to temp and give it enough time to clean any buildup off the clutches?








You've got thst maintenance list figured out.
It may not be 100% what is acting up but ALL these suspension parts with restore new-driving caracteristics. They are all loose/soft!
No need to split-hair on which part's the worst one.
Add to your maintenance :
forward control arms and
sway bar bushings (or new SB).
You've got thst maintenance list figured out.
It may not be 100% what is acting up but ALL these suspension parts with restore new-driving caracteristics. They are all loose/soft!
No need to split-hair on which part's the worst one.
Add to your maintenance :
forward control arms and
sway bar bushings (or new SB).

And I'd just do the SB links, cheap enough and easier that way.
















For reference, my car has is a 4matic with the sport package, no air assist thankfully.







