The Mercedes-Benz CLS Class gearbox sits at the heart of a luxury low-slung saloon first unveiled as a concept in 2003 and put into production from 2004. Spanning three generations through to 2023, the CLS delivers outstanding driving comfort and well-regarded mechanical reliability. That said, heavy use can cause premature wear to the transmission. How do you avoid breakdowns and keep the gearbox of your CLS Class in top condition? EDEN BOITES has the answers.
Which gearbox does the Mercedes-Benz CLS Class use?
Across all three generations, the CLS was offered with diesel or petrol engines (petrol hybrid for the latest version) and considerable power outputs, up to the CLS 63 AMG S 4MATIC with its 585 hp. As a grand tourer, drive is sent to the rear wheels or all four; in the latter case, a transfer case works alongside the gearbox to distribute power.
The CLS Class has always favoured the automatic gearbox, fitted as standard across the entire range. Depending on the year of production, it features five, seven or nine speeds, with the latest generation equipped with the 9G-Tronic developed by the Mercedes-Benz group. To understand how this component works, take a look at our article on how a gearbox works.
Gearbox oil maintenance and oil changes on the CLS
Whether automatic or manual, the CLS gearbox requires transmission oil to operate correctly. This fluid lubricates the entire system, cleans components thanks to its detergent properties, and dissipates the heat generated during driving.
Check the condition of this oil periodically: if it has turned very dark, it is saturated with metal particles and its effectiveness is compromised, meaning an oil change is needed. Also check the level using the dipstick markings; a low level may point to a leak that should be identified promptly. As a general rule, plan an oil change every two years or every 60,000 kilometres, so your CLS Class continues to run in optimal conditions.
Symptoms and diagnosis of a failing CLS gearbox
Staying alert to signs of trouble
An oil change is essential but is not a cure-all. A burning smell inside the cabin may point to the gearbox oil as the source of the problem. In other cases, the cause of the fault is less obvious, given the complexity of the transmission system.
Make a careful note of any unusual signs you notice in your CLS: noises, vibrations, or a general sense of power loss (sluggish acceleration, engine revving without response). These observations will help your mechanic make an accurate and reliable diagnosis.
Complex faults: a special case
If your gearbox develops a serious fault, your mechanic will not be able to repair it on the spot at the garage — it takes too much time and specialist equipment. They will then recommend a complete gearbox replacement.
Exchange or second-hand gearbox for the CLS?
You do not have to buy a new gearbox. Second-hand is cheaper, but its history remains unknown. The exchange option offers reconditioned gearboxes: our experts strip them down piece by piece for a thorough clean, replace any faulty components, then reassemble and test the whole unit with great care. This solution is both cost-effective and environmentally friendly, as your old gearbox is taken back and recycled. To find the right reference for your CLS, have your registration number to hand.
Frequently asked questions
How often should I change the oil in my CLS gearbox?
As a general rule, every two years or every 60,000 kilometres. Blackened oil or a low level should set alarm bells ringing.
What does a burning smell in my CLS mean?
It may indicate overheating and point to the gearbox oil as the source of the problem. Have the transmission checked without delay.
How many speeds does the CLS gearbox have?
Depending on the year, the automatic gearbox has five, seven or nine speeds, with the latest generation receiving the 9G-Tronic.
Does the exchange gearbox come with a warranty?
Yes, our reconditioned gearboxes come with a warranty of up to 24 months and a satisfaction-or-money-back guarantee in accordance with our Terms and Conditions.
Continue reading with our advice on the S Class gearbox and on the E Class.
Why choose EDEN BOITES?
EDEN BOITES supplies reconditioned gearboxes on an exchange basis — stripped down, thoroughly cleaned and rigorously tested. You make no compromises on quality or safety: all our products come with a warranty of up to 24 months. Payment can be spread over instalments, paying in up to 10 instalments, and we deliver throughout France and the European Union, with lead times confirmed on quote. Our exchange gearboxes are offered with a satisfaction-or-money-back guarantee in accordance with our Terms and Conditions.
Have your registration number ready, browse our Mercedes catalogue and get in touch for personalised advice tailored to your CLS Class.
