geckostev

How often does the differential fluid realistically need to be changed?

Teckno

In Australia, based on annual 12 month or 25,000km service schedule, MBAu have year 5 as the first time for Auto and differential oil change.
Not a cheap service as the auto filter is part of the auto casing and that part needs replacing along with new bolts. So 5 years or 125,000km, whichever comes first. We have a 9 speed box and 4Matic.

chassis

Do you mean front and/or rear axle differential? “realistically” it may never need to be changed. In practical terms it’s a good idea to change it before 100k miles. I changed both differentials and transfer case oil between 60k and 70k miles because I wanted to.

If you plan to own the vehicle to high mileage, replace the oil per MBAG’s schedule. Where no schedule is provided (axles), change the oil before 100k miles. Expect dealers to have no clue which axle oil should be used, because MB doesn’t specify changing it. Use the bevo site, WIS and this forum to select the oil.

seamus2154

I did my 2018 GLC300 RWD at 35,000 miles. The diff fluid was in really good condition and not burnt up at all. I did my S550 diff at 30K and it was like new coming out. I have not found this on all cars but Mercedes rear diffs must be polished or set up differently. So there is no rush, but a 50k change of the diff fluid would be good maintenance.

Teckno

Here is data from my invoice re 5 years auto and transfer case service.




I hope this helps you.
Cheers

chassis

With the GLC as with C- E- and S-, the transfer case and transmission share fluid. So a transmission service = transfer case fluid change, they are one and the same. Not the case with GLE/GLS/G, which used separately sealed transfer cases.

mikapen

Is the Oil Sump not re-usable, or was yours damaged?

Teckno

No damage. Sump has to be replaced as MB designed it with filter embedded in it, so new base every 5 years when filter changed, hence the price too.
No damage to vehicle, so I guess all parts replaced are part of the normal requirement.
I might buy the part next time and save 10-15% trade from spares and have service dept fit it during service. Savings all add up as normally no parts discount if Service Dept invoice me as part of service. I did same with brakes and discs and saved close to $500 or 20%.
Again you need to provide your veh VIN to ensure all parts supplied are correct for your build state if you go down that path.
Get approx quote first from Dealer for this work.

Kosie

Just had my GLC 250d done @ 120 000km (+/- 75 000 miles) And as said above, sump needed replacement. I had the opportunity to see the 'old' fluid, filter as well as the magnetic strip to catch metal filings and it was uncannily clean, to my untrained eye it looked just the same as the new fluid put in. Cost me about ZAR 7 800 (US$ 507) at an independent Merc specialist in South Africa.

DanD.

is this for sure? as according to the WIS it's not and required a different fluid vs tranny oil.

DanD.

Maybe it can help others, I found the WIS for rear diff, but nothing for front, if someone can share it, I would greatly appreciate it.

sn202020

I replaced 2017 GLC 300 4Matic's Rear diff. & front diff. oil.

Rear and front differential must use the same oil. 253.15 /235 7 spec 75w85. I used Redline 75w85 gear oil. But most synthetic 75w90 are also useful.

Rear diff. Drained 800ml. At 120k km odo.
Not bad.
Easy to refill thru the side fill plug.

Front diff. Drained 500ml. At 200k km odo.
Not bad. Red wine color. I could go 300k km easy.
The side fill plug has no room for 14mm hex socket space. The top black cap was not easy for filling. So i used Mytyvac to pump 550ml oil to the drain plug hole thru a plastic fitting and silicone plumber tape, then quickly replace the drain plug with some spill.

I believe most owners can call them lifetime oil.
or
replace at around 300k km(200k miles) if you drive a lot or you are bored.

sn202020

I thought transfer case oil is shared by atf of 9g transmission. But now I don't think so. Because your document says 0.65 liter "gear oil" mb 235.15 which is 75w85 gear oil and the same as differential oil spec.

But still I don't want to replace T.C. gear oil utill I drive more than 300K km, because i saw the rear and front diff. gear oil condition that was not bad at 200K km oil replacement.

DanD.

Hello, thank you for posting this, but I have to disagree to the specs, my reasons are attached.
Document AR33.25-P-0300-01LWX Drain/pour in front axle gear oil
referencing the sheet BB00.40-P-0235-07A which is
MB 235.7/ 235.74 FE-Hypoidgetriebeöl
001 989 33 03 12
75W-85

Document
AR35.31-P-0523LW Drain/fill rear axle gear oil
referencing the sheet BB00.40-P-0239-71A which is MB 239.71 hypoid gear oil
A 001 989 88 03
75W-85

Transfer case uses MB 235.15 spec document BB00.40-P-0235-15A

I have all docs attached. I might missing something, please let me know.

sn202020

Yes, You must be right,
but the Redline gear oil has all the MB specs.
https://www.redlineoil.com/75w85-gl-5-gear-oil
click tab of OEM Compatible. then see.so, I will put Redline into all 3 locations of
Front Dif/ Rear Diff/ Transfer Case.

Also I read 75W85 is mainly for the mileage efficiency of the old 75W90.
So i won't hesitate to put generic 75W90 synthetic instead of 75W85.

Anyway, you can still buy all the different OEM bottles from the MB dealership,
but I am a cheap guy, I do not waste money for the MB OEM oils.

DanD.

MB doesn't make oil, so I always buy by the spec, but from other brands
Ravenol, Liqui Moly, Pennzoil and Castrol are my preferences (and what is on sale)

Get this, now I found another document BB00.40-P-0231-01A in which MB recommends to use
Rear Diff spec 239.71 and Front Diff Spec 239.72 (75W-85) for Model 253 (2016 - 2019)
So Redline should work just fine, thank you for the link.
Still don't know why different specs in all documents, very confusing.

BlackML550

So Redline should work just fine, thank you for the link.
Still don't know why different specs in all documents, very confusing.[/QUOTE]

I believe that the change in the front diff oil spec was driven by wearing components in the front diffs between 2006 and approx 2010. Many W164s had this problem which is expensive to repair and the updated spec was part of the solution.

see this post for more https://mbworld.org/forums/m-class-w...ilure-fix.html

chassis

For posterity's sake, please use the operating fluids (formerly bevo) site for fluid specs: https://operatingfluids.mercedes-benz.com/

DanD.

Finally I got time to replace fluid in transfer case, frond and rear diffs at 39K miles.
TC has similar concept as trany, there is a little tube you have to pull in order to drain the fluid, and use pump to get oil up in the case. Could be easier but not bad. Diffs are simple, except front I couldn't get H14 with socket, had to kick out the bit and user it without socket using wrench.

Old fluids:
Transfer Case


Rear diff


Front diff


In TC and rear used Ravenol, simply because I had 2L of it and it meets the spec


Front diff, one dealer told me to use MB 235.7/ 235.74 another 239.72.
I would use Ravenol as it has almost all specs, but 239.72 but has 239.72
So I used Red Line as it covers them all.

Ravenol stinks so bad vs Red line ))

JoelCrow

I paid $500 for my transmission fluid and filter tray to be flushed and replaced by MB dealership local to me in SC. I've had this service done on both my ML350 as well as my GLE400 by them. I usually add it on to other things like brake flush, coolant flush and oil change just to get all my fluid refreshed in one big fat expensive B service that's like $2800 all together.

Alternatively, this guy shows you how to do it with FCP Euro parts at 21:55 in this video. If I had a lift like he does, I'd probably do more of this stuff myself as well


Take care
Joel

DanD.

Deleted. Wrong assumptions.

ninobrn99

Great thread! Learned a lot. Bought all fluids from MB as this was my first time, but from now on, I’m going to use the sensibly priced alternatives!