Differential/Final Drive fluid change
Thread Starter
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
Differential/Final Drive fluid change
So legit question, how often are you CDI folks changing this fluid and which of the umpteen oil specs/types are you using. I know this is gonna sound terrible but I have NEVER in 225k miles changed mine. I bought a full synthetic Motul 75w90 that meets spec supposedly and am changing it ASAP, easy enough to do. It’s just slipped my mind. I’ve done trans oil a couple times and it’s always clean....but man did I really overlook final drive. I figure I’ll probably change it now use that as a flush and change again with trans oil in a few thousand more miles next time I’m on lift for engine oil service. Just wondered if anyone had decided on a close to ideal readily available fluid, seems any GL5 and a few different oilweights are acceptable, just curious. I’m well aware that going as long as I did onstock oil was STUPID, so little need to drive that point home.
Member
Joined: Sep 2018
Posts: 207
Likes: 30
From: Ontario
ML350
not the same car here, mines a 2014 ml350 bluetec, but when i bought it CPO and had a indy mechanic do a pre-purchase inspection after the fact he actually recommended to have the diff fluids changed (maybe he checked the fluid somehow?). he said it wasn't urgent and i could keep driving for a while on it still, but i figured to be on the safe side i would do it anyways.
at the time the car had about 80,000 km (50,000 miles)
he did front and rear diff and the transfer case and here is the oils/info from my work order
85w90 oil
and
atf134
i think the 85w90 was for the diffs and im assuming the atf134 was for the transfer case maybe?
i think from some reading around diffs were to be done somewhere around the 100000km (63000 miles) or 125000 k (78000 miles) but i plan to be proactive and do them around every 75000 km (47000 miles)
hope this is helpful
at the time the car had about 80,000 km (50,000 miles)
he did front and rear diff and the transfer case and here is the oils/info from my work order
85w90 oil
and
atf134
i think the 85w90 was for the diffs and im assuming the atf134 was for the transfer case maybe?
i think from some reading around diffs were to be done somewhere around the 100000km (63000 miles) or 125000 k (78000 miles) but i plan to be proactive and do them around every 75000 km (47000 miles)
hope this is helpful
Super Member
Joined: Jan 2010
Posts: 563
Likes: 31
From: The Villages, Florida
2006 E320 CDI
I had my FD oil changed by the dealer in August 2013 at 92k miles. I now have 173k miles on my cdi. Since that oil change, whenever someone inspects the car they say the FD is seeping oil. I do not know if that is something that started when the dealer changed the oil, but it was never brought to my attention before. It does not drip on the ground, but it looks wet by the pinion seal. I have no plans on changing that seal as MB says the whole rear end has to come out to change the seal.
Mike T.
Mike T.
Thread Starter
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
They sell literally hundreds of different thread pitch plugs, it’s the same as one used on a brand of motorcycle we service. I’ll add details provided it really fits right. Headed to shop where my lift is now, as soon as my haircut is finished. My big celebrity event is Friday, need a trim something fierce lol. MotoGP circus arrives Friday for me here in Austin followed by a thousand mile drive to help my mom move. Inner tie rod and diff fluid. When I get back, transoil again and motor oil and filter plus fuel filter...I drive WAY too much
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Thread Starter
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
Well that was stupid easy....I did use a little Teflon tape on the tapered thread plugs, torqued to spec, 1.5 liters of Motul 75w90 GL-5 spec in final drive now. Completely depaneled and washed out, removed rocks (previously used car as U-boat accidentally after driving into a low water crossing 24” deep, car kept going, flooded interior quick, moronic move). So full depanel underneath and 250+ total lbs of rocks, and dirt and silt removed, obviously had to make or recreate some fastener points....oh and replaced entirety of wearing parts on front suspension and got it aligned....to go with new tires and brakes. The only thing that was even mildly disappointing was the 225k mile diff fluid still looked pretty clean, about like ATF at 100k intervals, which yes I know, I also technically way to big a stretch.
I need to get a spare lift to keep outside so cars so cars can be properly cleaned from bottom, I’m sure there was a couple hundred lbs of stuff I simply couldn’t clean off. Need to weld a pipe bracket too...never ends, always something by 225k miles of hundred mile daily driving commuting.
I need to get a spare lift to keep outside so cars so cars can be properly cleaned from bottom, I’m sure there was a couple hundred lbs of stuff I simply couldn’t clean off. Need to weld a pipe bracket too...never ends, always something by 225k miles of hundred mile daily driving commuting.
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MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,225
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From: V E G A S
1922 Ford Model T / no OBD
Had few MB with 300,000 miles and very likely factory oil.
To add some reality to chat - cars float in about 12" of water. They will sink with the time when water finds the way to get inside, but rear wheels will be off the ground before water reaches door sills.
Don't ask me how do I know
Thread Starter
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
They float, then sink as the interior fills....then somehow mine kept going, most of my interior was destroyed or damaged, took a week just get carpets truly dry. Btw, most disappointing thing about the final drive oil change was the 225k Mile oil looked perfect lol. Slightly darker than replacement but still far less nasty than expected.
As for driving into water...I live way out in the sticks, only two roads lead to my home road. The first possible route had flowing water, the second what appeared to be just under 12 inches on the FIRST flood stage monitor stick, 18-24” showing on the second and third gauges and about a foot on the last one. I made a STUPID decision, should have just gone back to work and slept in RV. I know better than to do something this dumb, not sure exactly why I drove into the water other than I could see what I assumed was the “other” flood stage marker, not a route I normally take, didn’t realize there were four total gauges in that stretch. Once I was into it and my feet started getting wet I realized I was likely f%cked, strolled down windows and opened sunroof and just tried to keep momentum at 10mph or so. STUPID like I mentioned earlier.
As for driving into water...I live way out in the sticks, only two roads lead to my home road. The first possible route had flowing water, the second what appeared to be just under 12 inches on the FIRST flood stage monitor stick, 18-24” showing on the second and third gauges and about a foot on the last one. I made a STUPID decision, should have just gone back to work and slept in RV. I know better than to do something this dumb, not sure exactly why I drove into the water other than I could see what I assumed was the “other” flood stage marker, not a route I normally take, didn’t realize there were four total gauges in that stretch. Once I was into it and my feet started getting wet I realized I was likely f%cked, strolled down windows and opened sunroof and just tried to keep momentum at 10mph or so. STUPID like I mentioned earlier.
