Does my Mercedes need Differential Service?

Mercedes are a very special breed of car the owners drive. These are products of high craftsmanship and the latest technology possible. The advances in design and automotive parts have had the benefit of extending the time intervals for service. Oil changes used to be mandatory every 3000 miles; they are now needed anywhere from 5000 to 7500 miles. Mercedes makes a point of letting people know that the newer models have lifetime fluid in the differential. That implies that there will never be a need for the differential fluid to be changed and this can be a bit misleading.

2008 MY CL65 AMG

The differential in a Mercedes will transfer power from the engine to the wheels and at the same time allow the wheels rotate at different speeds. This helps in making turns. The gears of the differential will turn at the rate of 5000 times a minute or more and are straining against the car’s full weight all the time. With that type of activity it is possible that tiny metal shavings can come off the gears and flow through the system as part of the differential fluid. Unlike a transmission, the differential does not have a filter to keep the fluid clean and dirty differential fluid will eventually cause some internal damage. The great amount of heat generated by normal driving conditions can ultimately cause the lubrication elements of differential fluid to deteriorate. Consequently, many mechanics recommend that differential fluid be changed every 30,000 miles.

Confusion can surface when a car owner is told that the Mercedes has lifetime differential fluid in it. The assumption is made that this means differential fluid never has to be changed for as long as the person owns the car. That is a little bit misleading. Anyone who purchases a used Mercedes buys a car that has already spent several years or more of its “life”. The longevity of the car is also influenced by how it is driven. The occasional trip to the store type of use will extend the life of the vehicle, and also cause less stress on the differential. However, a steady diet of stop and go traffic or rough driving is going to age the car. It all means that lifetime fluid may have to be changed at one point or another.


The differential definitely needs to be serviced if warning signals start emerging from the car itself. Loud noises that occur whenever switching lanes or turning a corner may be a warning that the differential starting to fail. If the service engine light comes on in the car, it is possible the differential is having some difficulty as far as fluid is concerned. The differential can never be completely ignored. Neglecting to attend to it can result in a very bumpy ride, which should not happen with the Mercedes. The worst-case scenario would the gears breaking down and that will result in some fairly expensive repair work.

The best way to think about lifetime fluid is that more miles are to be added before a fluid change is made. Instead of every 30,000 miles, that required fluid change may occur every 60,000 miles. Taking a look at the manufacturer’s guide or the owner’s manual can give a better idea of the timing of any differential fluid change.

The owner of a Mercedes has to understand that while he or she may have an amazing car; it is still something that has been manufactured. A Mercedes has to be given proper attention and maintenance, even if it has qualities such as lifetime differential fluid. The older models might not have lifetime differential fluid. At the time of a fluid change the owner can decide whether or not to use the lifetime fluid instead of more standard brands. It has to be remembered, though, that this type of fluid may be a little bit more expensive than the ordinary kind. Nevertheless, the lifetime fluid will mean that the intervals between fluid changes can be stretched out thousands of miles.

Maintenance and servicing speak to the overall life expectancy of the Mercedes a person owns. Routine inspections of the fluid levels should be part of any routine maintenance or tune-up. Usually these tours of the internals will not uncover any major problems. Dirty differential fluid is a sign of difficulties to come, and if this is discovered the car owner may want to go ahead and have a differential fluid changed rather than wait.

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