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Don’t let it grind your gears.

Owning and enjoying a luxury car is one thing.  But understanding the mechanics of the vehicle is a whole different issue.  Some people make cars their hobby.  They spend their free time maintaining them, cleaning them, polishing them to within an inch of its life.  Others enjoy a nice car but don’t know much about the maintenance needed to preserve the vehicle and keep it going for longer.

Sadly, we have seen several vehicles with faults that could have been avoided with just simple regular servicing over the years.  The service schedules are designed to give the client maintenance guidelines to elongate the life of the car.  

Our customer brought his Mercedes S-Class luxury car back in 2012. Like a lot of people, he had been busy with day to day life, which meant he hadn’t always kept on top of regularly servicing his vehicle. He got the car to us advising that the gear changes were ‘clunky’ and the car didn’t seem to accelerate smoothly anymore.

A properly functioning gearbox is key to the vehicle’s overall performance and safety, so we knew we had to get the issue resolved to make sure Mr K could enjoy his Mercedes again.


The S-Class came to us at Fitch Autos, with a sketchy service history.  The service schedule offers guidance about when certain parts of the vehicle should be serviced, changed or replaced.  Unfortunately, if the car isn’t taken in for regular servicing, some of these intervals get missed, which can cause a bigger problem in the long run.

Accessing the Digital Service History (Mercedes DSB) confirmed that the S-Class had never had the gearbox serviced, even though it had done over 100,000 miles.

To get this Mercedes back to functioning at its best, we started with a full service to the automatic transmission.  

Part of the gearbox service is to complete a “MegaFlush”.  So a gearbox could hold up to 12 litres of oil, and when you remove the sump pan, gravity will usually give you 5-6 litres of old oil.   If you add new oil at this stage, you will only increase the dirty oil circulating through your engine.  So it’s essential to complete the MegaFlush to clear the system of the old oil. 

We fill the system with 15 litres of quality grade gearbox oil for the flush, meaning the system will dump the old and replace it with the new oil.

Changing 99% of the oil within the gearbox will make a noticeable difference to the car’s performance.

After completing the MegaFlush and replacing the sump pan and all the associated seals, our technicians then reset the adaption values and set the gearbox oil level to 45 deg C. We took the S-Class for a test drive, and it was like driving a different car.  The gear changes were smooth, and the vehicle was able to accelerate and decelerate properly.


Another garage had previously told Mr K that he would need a completely new gearbox to get his S-Class back on the road.  Our evaluation process meant that we could carry out a full assessment of the vehicle and identify and fix the fault without the stress and expense of a new gearbox.

Our specialist technicians, along with our unique 15 step evaluation, means we invest our time into locating the root cause of the problem, rather than swapping parts out while still potentially having the underlying issue there.  We pride ourselves on our training, experience, and ability to save our clients time and money on a top-quality fix.

Mr K left our garage with a working gearbox and some guidelines on caring for his Mercedes-Benz going forward.  Regular service intervals are so important in keeping your vehicle from becoming a potential danger to yourself and those around you and ensuring the longevity of your car.

Our team of expert technicians are here to take care of your Mercedes. So if your service is due, or if you would like a vehicle assessment, book in with one of our team today.

Call 01543 452630Save on Mercedes Servicing