Originally Posted by safesphere (Post 4968961)

I would never keep used engine oil in the car for as long as 10k miles. I know it is recommended, but there is no harm in changing it sooner. It used to be 3k for mineral and 5k for synthetic, but in fact even synthetic does it's best only for the first 1 to 3k miles depending on the brand. So I am sticking with at most 5k. The pennies you save on extra oil you pay back in gas for more friction anyway. I think longer intervals are driven by environmentalists and green initiatives and only provide for your car to last during the warranty period, same as the "lifetime" differential lubricant or "lifetime" transmission oil on VW.

Originally Posted by jctevere (Post 4968986)

Okay, so I think its settled then. The w204 4matic "transfer case" is non-existent as it has been integrated into the transmission and shares the same fluid. (:y !)

Now I think the only debate is on the differentials. Should the fluid in the front and/or back ever be changed? I am never against changing something, as it can't cause any harm. My only fear is that if it wasn't designed to be replaced (filler and drain plugs), it could cause problems when you try to replace it, and may cause more harm then good if you have to start messing with seals, etc. (My 350 4-Matic does have the service plugs on the rear differential only and yes, the rear differential fluid needs to be serviced even though it is not on the official service interval... (please see your Maintenance Schedule Booklet)... Inspect every 4 years or 50,000 miles. If it's contaminated or smells burned, I would replace it. The front differential on my 4-Matic is not serviceable.. there are no drain or filler plugs. )

I'm not so upset that I provided wrong information from the e-class. It seems it has spurred everyone to do a bit of research and we have come up with great findings and stomped out any uncertainty.

Thanks for all the info and hard work!

Also, as far as changing engine oil every 5k, you are right, it can't do harm, but it offers negligible benefits and I would consider a waste of time, money, filter, oil and effort. I highly doubt that you will save upwards of $100 in improved fuel economy by having new oil every 5k as opposed to 10k miles. There are better ways to save on gas or improve fuel economy (such as driving style, making sure air filters are clean and free of debris, proper tire pressure).

Mercedes has MUCH larger oil capacities than other manufacturers. Synthetic does not mean 10k interval. My escalade uses synthetic and runs on a 5k interval. The fact that mercedes calls for fleece filters over traditional paper filters, as well as a much larger oil capacity allow for 10k oil and filter change intervals.

Originally Posted by jctevere (Post 4970317)

Hmm, seems odd that the rear would have plugs and the front wouldn't... Perhaps they are just hard to access and/or see?

Glyn, hopefully you can solve another mystery of mine. A friend of mine has a 2008 c300 4matic and it has a "kickdown" switch on the accelerator where when you put the pedal to the medal, you can press a little further to make the car downshift. This feature is missing on my 2009 c300 4matic and my 2011 c300 4matic. What gives?

Originally Posted by Glyn M Ruck (Post 4969576)

+1 This has been a great thread & got me up to date with W204 4Matics which are not produced or sold in SA due to no RHD.

Originally Posted by jctevere (Post 4970317)

Hmm, seems odd that the rear would have plugs and the front wouldn't... Perhaps they are just hard to access and/or see?

Glyn, hopefully you can solve another mystery of mine. A friend of mine has a 2008 c300 4matic and it has a "kickdown" switch on the accelerator where when you put the pedal to the medal, you can press a little further to make the car downshift. This feature is missing on my 2009 c300 4matic and my 2011 c300 4matic. What gives?

Originally Posted by Glyn M Ruck (Post 4970771)

The plug on early cars is not difficult to see. It's a pity if it's been deleted because that is more planned obsolescence.

The kick down switch removal was market specific. e.g. retained in Canada, deleted in USA. What the rationale was other than cost saving I do not know. Will try and find out.

This was done on many models. See from 2009 CLK owner’s manual for NA. Some sense from TPS hall sensor input & some with hard switch. All AMG have kickdown switch.

https://mbworld.org/forums/attachmen...1&d=1324461612

https://mbworld.org/forums/attachmen...1&d=1324461612

Originally Posted by Glyn M Ruck (Post 4966429)

The TC holds nearly half the fluid in the transmission. Make sure they drain it at service & replace the plug with a new microencapsulated one.

Originally Posted by LandSeaAir (Post 4999231)

Taking my car to my mechanic for this tomorrow, worried he doesn't know to do this, and don't want to be "bossy"

Noticed when he did my dads S's 7 speed he only used 8 of Mercedes Benz fluids, I don't know what size they were sold in, I'm assuming quarts. According to the manual, my dads transmission uses 10.36 quarts, so there 2 quarts of old oil in there? I hope that isn't a problem....

Originally Posted by kevink2 (Post 5000178)

Here is a DIY thread about automatic trans oil change ... informative. He speaks of changing the TC oil too.

DIY 722.9 7G-tronic 7-speed Automatic Fluid Change

Glyn, do you recommend the new atx flushing service?

.

Originally Posted by LandSeaAir (Post 5001137)

Dropped my car off to my mechanic this morning, he finished already and I'm picking it up tomorrow. I trust him, and I'm sure he knows he has to drain the TC, he's been working on imports for over 15 years. I feel pretty good I got it done, only for ~$300. I know we came to the conclusion of 100,000 miles, but I'm gonna ask him what he thinks about the differential fluid just for kicks.

Originally Posted by jctevere (Post 4967197)

Not filled for life. Word of advice, never second guess Glyn, haha.

To summarize:
1) Front and rear 4matic differentials are advised to be flushed every 100k miles.

2) Change engine oil and filter every 10k miles (duh!).

3) Perform transmission fluid flush (which simultaneously flushes transfer case for 4matic, as they are connected) and replace filter (also make sure torque converter housing is drained via separate drain plug) every 39k miles.

4) Perform brake fluid flush every 2 years.

Some of the above maintenance is not "required" but HIGHLY recommended. And no, not recommended like your dealer trying to get a few extra bucks, but recommended as in will save you numerous repair bills and headaches down the line/out of warranty.

I would also like to add that at the same time the brake fluid is performed, I would also do a laser alignment and 4 wheel road force balancing. In my experience, in my areas (with the terrible condition of the roads) 2 years is just the right amount of time when I start to feel vibrations and my alignment starts to get out of wack. While these may seem "extra" or not needed, if your alignment is off it could give you uneven wear, making even new tires worthless and garbage in a matter of miles 10-20k.

Glyn has also previously recommended to install fluted bolts so you will be able to adjust castor or camber when performing alignments. (This will get rid of slight pulling to right by having a 1 degree additional positive castor on the RHS (so LHS = 9.6, RHS = 10.6 degrees) due to camber in the road surface, even if your alignment was just done and is good).

Originally Posted by craiger13 (Post 6451586)

Gentlemen I have a question I have a 2011 w204 4matic and I just bought at 41k mile and I have NO past service history. so what can I do take it to a dealer and ask them to check? I mean this is very important to me I dont want to tell them to change the fluids and it doesnt need it.