2007 ML 420 CDI front diff grinding noise




This will tell if it's the diff, tire noise, a wheel bearing, or even the transfer case.
Don't bother going to the dealer, they'll sell you one they've replaced the bearings on for $3500-$4000 + labor.
They don't have new ones anymore.
People wondered what they'd do with all those bad diffs, now we know.
Bearing kits can be purchased here. at benzexpert.com. Your total cost for repair (assuming it's the diff)
should be $650- $1000 tops depending on if your replace all the bearings and seals,
or just the carrier bearing, the most common point of failure, + labor, anywhere from
$500 to maybe $800. (I paid $500 in San Jose, CA 2 years ago)
Where are you located?
Sent you a PM.
Last edited by C230 Sport Coup; Jun 20, 2016 at 05:18 PM.




In my case, you didn't hear it until you got over about 40 mpg,
would royally roar around 55-65, and due to the higher frequency, seemed to taper off if you hit 75.
The frequency of the whine increases with speed, as it is a one speed
diff.



