I've got a 2000 ML430 with 110,000. Its recently started making a sort of whining noise(not ebox fan or steering pump). At low speeds you can hear it over the engine noise and at higher speeds the normal engine and road noise are louder. It only occurs while driving, there is no noise while in park or at a stop, only normal engine noise. To me it sounds like it might be coming from somwhere on the passenger side front of the vehicle. Its not tire or suspension noise either. I'm just guessing maybe front differential or transmission, but I'm not an expert. I just changed the transfer case oil(old stuff was pretty brown) and engine oil/filter. However i've never had a transmission issue and it still shifts and drives like it should. The noise also does not fluctuate with the shifting of gears either manually or automatic, its just a steady whining noise. It seems like it get less prounounced as the car heats up as well. Does this sound familiar to anyone....i'm dreading bringing it to the dealer, they can be so out of control. Any help or insite would be greatly appreciated, other than a sloo of problems, i still love my ML.

It sounds like the driveshaft center support bearing may be the problem. It's a pretty common problem on ML's. Prices can vary, but expect to pay about $500 to have it replaced at the dealer.

did you check the fluid level in the front differential? the input shaft seal is suspect and you may be getting low on fluid.

Jim in Phoenix

ILUVMLS - the driveshaft center bearing thats something i hadn't considered, thanks for the info, I will look into that further. If this is the issue i'll bring it to and indie shop because the dealer will almost certainly rip me off.

jfreezn - yeah the fronty diff, thats was i was thinking as well. We just got a big winter strom in the northeast , as soon as this damn snow melt, I'm gonna check the diff fluild and replace it. If that doesn't work, its on to the dreaded shop.


Thanks for the info, its much appreciated.

OK all said and done I rode around with this annoying sound for two weeks. No loss in performance, tranny has always shifted smoothly since i bought the truck. The noise was a kind of "winding" noise, noticeable while driving 5mph to 70mph. The sound would wind up until about 70 and then disapate. My first attempts to diagnose the issue was to replace/inspect transfer case fluid, front and rear differentials and engine oil. All were decent and fluids were replaced anyway. Found no other leaks and the underbody looks great for 110k. Car ran great but the noise was still there. So I took it to the shop this morning and 20minutes later the mechanic calls and confirms what others on the board had suggested(thank god for the message boards!!best thing for car owners to get informed!).....the driveshaft center bearing needs replacing. He quoted me a cost of around $400, which i though was reasonable . Im in NJ and the shop i'm using seems very reputable and knowledgeable about MB cars......

The German Car Shop
2229 Rt. 27 Edison, NJ


Thanks for all the input, ....despite the numerous problems, i still love the ML and don't think i could go back to driving anything other than german, i like to drive to much!

Before you do anything else open the passenger door and get down on the floorboard so you can inspect the right evaporator water drain. These are knocked of the box many times and will transfer road and engine noise up through the rubber hose.