Differential fluid in 2014 ML 350 W166
 

Hello All,
I would like to clarify some information, I did transmission filter and oil change at 55K
At that time I have asked my service adviser if they can change differential fluid also.
Answer was, because trany fluid flows through its nothing to change.
Is this a correct statement?

I couldn't find differential fluid change in the maintenance schedule. Trany service is at 70K.

I have trouble believing that the diffs are fed from the tranny. I could stretch my imagination and say maybe the t-case and tranny are using the same oil source, though I've never heard of that. But the diffs?

i don't know who this is, but it validates what i thought. trans fluid is lightweight. https://www.bgprod.com/blog/low-visc...ain-intervals/

gear lube (differential) is heavier. probably what peter said, tech was talking about the T-case. good luck, ron

Both diffs use 75W-85 hypoid gear oil (MB 235.7 IIRC), but it is not scheduled to be replaced as part of regular maintenance, i.e. they are filled for life now that cars are "perishable" goods. If you are a masochist and looking forward to the pain of owning a ML (a diesel one at that!) for more than 10 years, you'll want to replace the diff fluid every 100K miles (160K km) so that it will outlive the rest of the car by a factor of 5 instead of just 3. :)

and if you need the part number for the 75w-85 fluid.... it is # A001-989-33-03-12 which Im sure you can order from Pelicanparts or FCPeuro or Amazon

wrong information, that is correct for passenger cars where the transfer case in built in on the tail off the transmission, w166 transfer case does not share fluid with transmission

Thank you, now Im ready for a nice conversation with my service adviser ;)

I want to keep this car for as long as it can last, actually till I see the oil leak :))

2014 ML 350 Blutec Differential and Transfer Case Fluid Change
 

I know this is an old topic, however here is my take as a DIY'er attempting this servce the first time with the original 80K mi on the fluids. I started by removing spash guard - by far the hardest part of the job and I had the vehicle on a lift! Tool needed: 7mm, 6 pt socket for the splash guard screws. Rear Differential: Tools needed - 14 mm Allen x 1/2" socket (found one at Auto zone), 1/2" breaker bar and a 5"-6"x1/2" drive extension to get to the fill plug over the exhaust pipe. The drain and fill plugs are the same size. The plug threads are inclined like a pipe thread, so the is no "O" ring or crush washer. I replaced the plugs (dealer purchase) as thery were pretty corroded. Capacity = 0.95-1.2 liters; Drain/fill plug torque = 50 nm. Capacity and torque spec per dealer. Fluid: MB 75W85 hypoid gear oil from dealer. Old fluid was black. New fluid is clear with a light tan tint. So, it needed the service. I will probably repeat after 30K mi. Front Differential: Leave it to MB, the drain/fill plugs are different from the rear diff. Tools needed: 8 mm, long shank Allen wrench; a 12" length of pipe to slide over the shank of the Allen wrench to gain leverage to break the fill plug free (I used a piece of 1/2" PVC pipe); an 8 mm Allen x 3/8" socket for the drain plug. The Allen wrench is needed as there is an obstruction preventing use of a 3/8" socket wrench. The drain/fill plugs are the same size. I bought new plugs from the dealer. These plugs have "O" rings, so those needed to be replaced anyway and the dealer said the "O" rings alone were not available. I found replacement MB "O" rings for these plugs at FCP Euro and will purchase a 1/2 dozen for future services. Capacity = 0.8 liter, drain/fill plug torque = 35 nm, both specs from dealer. The old fluid was black, so it was time for the service. Fluid for front diff is same as the rear diff. Will repeat this service in 30K mi. Transfer Case: Again a different drain/fill plug! These plugs are easy to access. Tool needed: 8 mm Allen x 3/8" socket. Both plugs are the same size and each takes a copper crush washer, so purchase new crush washers. I ordered them from the dealer. Fluid: MB ATF 134. The fluid color is red. I purchased it from the dealer. Capacity = 0.53 qt (yes qts, not liters!). Torque on drain/fill plugs = 25 nm. Both specs per dealer. Fluid was reddish-brown, so it was time for this service as well. I will likely repeat every 20K mi since the transfer case is prone to problems, from what I have read. I confimed what has been observed by other members - fluid came out of the fill hole when the plug was removed. Somehow the factory is squeezing a bit more than 0.53 qts into the transfer case. I followed the standard fill procedure - fill to overflow out of the fill hole. I spent weeks reading all the blogs on this topic and glad I did. The service took me two hours flat. Of that time, 45 min was removing and reinstalling the darn splash guard! Thanks to all others for the great advice and warnings! Ask the dealer for the "shop price" for a 10%-20% savings. All they can say is no.

YES! THANKS for breaking it all down! Really appreciate the details. Confirmed my 2 hours of searching and reading for my 16' GLE350 4matic, this applies 100%. Yes, the Transfer Case takes the RED ATF 134: 001-989-68-03-13 (236.14) fluid, even though the Transmission requires the Newer BLUE ATF 134 FE: 001-989-77-03-09 (236.15) fluid. Have fun guys.

Replace all drivetrain fluids at high mileage, let's say 100,000 miles or higher. Sealed for life is a myth perpetuated by Toyota, Volkswagen, Mercedes and other dealers. All lubricated mechanical devices benefit from good condition lubricant.

differential oil
 

Hi there, I'm new here do you have videos on how to change the rear and front differential fluid on 2014 ML30 W166.

Thanks

https://mbworld.org/forums/m-class-w...-thread-5.html

Post #103 - rear differential
Post 104 - front differential

You may want to change the transfer case as well

Documented in the GLE Ownership Report thread in the W166/GLE section.

Thank you @brakingbadly for posting up your guide!

I just did the front diff and transfer case while I was already under there when changing my oil. The fluids were somewhat black and my transer case fluid was overfilled from the factory so I was happy to set it at the right level.
I didn’t have the right tool for the rear diff so I will have to tackle that another day.

I expect the front diff wasn’t active much since they were still fairly clean. Just means that the previous owner wasn’t doing donuts in a parking lot on a snowy day, right?!

The front diff is continuously used. It's how you go around corners! The outside tire travels further!

The front diff is continuously used. It's how you go around corners! The outside tire travels further!

Thank you! This is my first AWD vehicle that is rear biased so I didn’t know that.

Not sure what your previous vehicle was.

FWD - Transaxle, transmission and differential all one piece.
RWD - No front differential because the front wheels are separate from each other.
AWD - Does not matter who's AWD, there is a transmission, transfer case, Automatic transmissions usually means a separate differential, Manual Transmissions, usually combine the transmissions with the Front differential.

In other words, ALL AWD have a front differential because the 2 front wheels are driven and therefore joined.

I hope this clears things up.

yes it does! I own a mk7 GTI and a 128i, but before that it was a 190E 5 speed and a mk4 gti.

Where did you guys get the oil for the transfer case and front/rear differentials in Canada? Obviously you can get it from the dealership, but their prices are going to be nuts. I checked Canadian Tire and they don't carry any suitable fluid.

Any suggestions? I'm due to change the fluids (changed them at 150 000 km and the ML is now sitting at 250 000 km).

Get it from the dealer. It's a liter of oil, even if the dealer price is triple, does it matter?

I can just imagine your typical American reading that and going "Whaaaat?" LOL

I found some on the website germanparts.ca

https://germanparts.ca/parts/fu80238...d-fe-75w85-1l/

3L should be enough right? According to the previous post, it's 1.2L for the front differential and 0.8L for the rear differential.

The website also has decently priced rotors (ordering the Zimmerman rotors all around with the Sports pkg (p31 code)) and transfer case fluid.

Just a FYI in case people read this post and need a place to shop for parts. I usually use Rockauto but their shipping prices were through the roof for the heavy rotors.

did you check out and price the cost from FCPEuro? with their lifetime exchange for parts it may be worth the shipping costs if you mean to keep the car a while and do more than 1 brake job
I also used rockauto last time, but that was pre covid and even with shipping the powerstop brake kit was the best price from anywhere else i checked. For my next brake job im considering FCPEuro as ive heard some canadians still use it and find it is worthwhile cost wise + quality of parts.

Yes I did. They're more expensive than Germanparts.ca but the lifetime warranty is worth the difference. However, I plan on selling my SUV in a year or two after the AEM... so choosing the cheaper option makes sense.