Hello Scotty and the community, I hope you are doing great! I have a 2006 Mercedes S65 AMG (w221) and I drive it as a weekend toy (made in Germany, it's a Swiss car). It has 63k miles and a 5-speed automatic. This model has the ABC suspension which has oil in it. Mercedes says, that oil doesn't need to be changed because it is a closed system. By that logic, the engine and transmission oil shouldn't be changed either? This ABC suspension of the predecessor model (w220) was known for having issues and being sensitive, but they fixed these problems with the next generation (w221, which I have) and allegedly wears out like any other suspension would. Non the less it can be maintained by changing the suspension oil. Some recommend a change every 20k miles, some say 50k miles, some say 100k miles and others say not at all. What is your recommendation? Unfortunately I don't know if the suspension oil has ever been changed, but I don't think it was. So far it's fine, no strange noise or squeaking or anything. What would you recommend? Love your content!!!
Kind regards, Stefan
By that logic, the engine and transmission oil shouldn't be changed either?
It's not the same logic at all. Engine oil is subject to blowby, heating/cooling cycles, viscosity change, and additive depletion. Transmission fluid is also subject to heat/cold cycles, additive depletion, and viscosity change, as well as accumulating small amounts of filings from gears over time, as well as friction material from bands and clutches, during operation.
I am not familiar with your oil-filled suspension system but after 19 years it probably wouldn't be a bad idea to change the oil if feasible to do so.
@chucktobias Thank you for the response! This ABC-suspension actually is also subject to heating/cooling cycles and also has additive depletion, although the operation doesn't nearly have the impact on it like the friction material from bands and clutches with the transmission. Alright, perhaps I'll change it sometime soon once or just leave it be as Mountain Man Joe advised. Have a great day and all the best to you!
No, suspension oil would be more akin to brake fluid which doesn't need changing that often. I think I would just use it until it wears out and then replace it with something simpler.
@imperator Yes, that makes sense. Alright, I'll keep this in mind! Thank you for your response!