Changing 722.6 tranny fluid and differential service ...
 

2000 C230K
55.5k

Hi friends -

Hope this finds everyone doing well. Am quickly approaching the 60k mark on my C230K, and will probably be looking to do a transmission service around this point.

I've been reading some posts about this as of late, and from what I understand, most versions of the 722.6 do not have a drain plug which will allow one to easily drain the fluid from the gearbox in order to properly change the fluid. Only a portion of the fluid can be siphoned out, and in all actuality, you're only really replacing a relatively small amount of the actual fluid.

What is the best way to go about doing this to ensure that as much of the fluid is drained as possible? I've read some posts which say that folks have drained and replaced their fluid anywhere from 4x-6x to be sure that all of the old fluid is out. For someone who will be having his indie do it, that's a lot of $ for transmission services! :eek: I want to know the most effective and efficient way to go about doing this.

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On a separate note is a question about the rear differential. Have been reading that the gear oil should be changed anywhere between 60k and 100ik, while most posts are leaning more toward 100k. Is it OK to go this long, or should it be done before that?

The car has been doing great - really a pleasure to drive and extremely dependable. I've been a happy camper, and averaging 32-34mpg on an all highway tank to boot! The best of all worlds.

Many thanks for your advice and replies, and take care,
Michael

The most effective procedure to insure 85% fluid exchange is a flush. The problem I see, most shop are not willing to the remove the pan , inspect for EXSSESIVE metal and clutch contamination, if none or minimal change the filter, then flush.
The irony is most Mercedes dealer have a transmission flusher, for a filled for life transmission.

For peace of mind, you can change the differential fluid at 60k if you want. It's subjective, but I usually change mine at 60k intervals. I don't think going 100k will hurt anything since Mercedes does not even have a formal recommendation on ever changing the differential fluid.

Suggestion in differential oil changes ....

Always remove the fill plug first. That way if you have a problem you can always refill it. If the fill plug won't come out and you have already drained it .....

Haasman

My diff was done at 90k, and i was told the fluid looked great.