Yes 3L is enough oil.

Ty sir!

I finally did the rear differential and I installed new fill/drain plugs because the originals were heavily corroded.

Here is my question, I only bought 2l of the gear oil for the front/rear diff. For the front I filled up until I saw oil leak out. Which left me with about 1.1-1.2l for the rear. When I emptied the full liter and the remainder in the other bottle, no differential fluid leaked out like the front.

is that normal? I know I definitely have at the absolute minimum 1.05l in the rear diff.

The fill procedure is to overflow with the vehicle on a level surface. You may not have gotten every last drop of oil from the bottles into the axle, or the vehicle may not have been level. And if I recall correctly there are several fill volumes depending on vehicle specifications. If no fluid came out, the axle was not 100% filled, or the vehicle was on a nose-up incline.

Thanks, the nose is actually lower than the back. Meaning that if I were to let the truck go into neutral it will roll forward instead of backward. Why did the previous post say that the fill is .95-1.2l?

I have diff oil in my basement for my BMW, maybe I can just top off with that.

Fluids
 

So all stores in canada recommended

LM22090 liquimoly. It’s 75w-90 and recommended is 75w-85. Dealer wants $75+ tax a litre. That germanparts fusch is right weight but not on Mercedes bevo site.

What exactly is your question here? Whether you can cheap out and save $50 by putting in an unapproved diff fluid?

It's your car - you can put in olive oil if you want to. Just don't blame Mercedes for your gas mileage going down (which it will) and when the diff prematurely fails.

Asking about spec
 

I am just trying to figure out if anyone here used liquimoly 75w-90 as suggested by local parts shop. Dealer dosent have any in stock at $75/L. He said should be coming in mid June plus new fill and drain plugs.

fcp website also suggests liqui moly. Not trying to cheap out or use olive oil. Just looking for suggestions regarding fuschs vs liquimoly

The old MB 235.7 hypoid gear oil standard has been now superseded for the W166 (and what you're likely seeing on the FCP Euro site is the ATF, which is NOT the differential fluid). Mercedes BEVO specifies sheet 239.71 for the rear axle differential and sheet 239.72 for the front axle diff on the W166.

Sheet 239.71 - updated yesterday - says that the approved diff fluids for the rear diff are

Product name 75W-85 Principal
Rhodium ST Pakelo Motor Oil S.r.l., San Bonifacio (VR)/ITALY
Mobilube FE Plus NG 75W-85 ExxonMobil Oil Corporation, SPRING, Texas/USA
MB 239.71/239.72 Hypoidgetriebeöl A 001 989 88 03- Mercedes-Benz AG, Stuttgart/GERMANY

Sheet 239.72 - also updated yesterday - says that the approved diff fluids for the front diff are

Product name 75W-85 Principal
Rhodium ST Pakelo Motor Oil S.r.l., San Bonifacio (VR)/ITALY
MB 239.71/239.72 Hypoidgetriebeöl A 001 989 88 03- Mercedes-Benz AG, Stuttgart/GERMANY
Fuchs TITAN SINTOPOID FE 75W-85 Fuchs Petrolub AG, Mannheim/GERMANY

So - you need to get either the Mercedes 239.71/239.72 Hypoid gear oil (A 001 989 88 03- ) or the Rhodium ST which is not available in NA.

Both diffs are essentially "filled for life", so why the rush to change the diff fluid now to something unapproved if your dealer will have the MB 239.71/239.72 oil in June?

Blue ATF 134 vs red?
 

I got the MB brand diff oil from IDParts.com...US$33/liter. Best price after shipping ($10 for 2 liters) Ive found.

Transfer case question, I have BLUE Pentosin ATF134 left over from my tranny service, was going to use that for xfer case service. Post above indicates Xfer case ATF 134 is red. Is there a difference beyond the color?

Post 9
 

From post #9
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.

Bevo
 

Someone at Mercedes must be reading this thread lol. I can now use Fuchs TITAN SINTOPOID FE 75W-85 from germanparts.ca
thanks for pointing out the update may 20, 2022.

https://cimg9.ibsrv.net/gimg/www.mbw...9eb8741fa.jpeg
rear
https://cimg0.ibsrv.net/gimg/www.mbw...debb5fb3c.jpeg
front

That is incorrect (it was incorrect back when it was posted as well). The old transfer case fluid standard was MB 235.7. MB 236.14 was the ATF standard, which again is NOT the same fluid as what goes in the diffs.

The Fuchs Titan is not approved for the rear differential on a W166 - only for the front. You posted the same picture (front diff) twice. If it's approved in one but not the other, chances are that the fluid formulation itself has changed and that the two diffs on the W166 use different seal and/or other materials internally so the new Fuchs contains something that is not compatible with the seals on the rear diff but is fine in the front. Again, I don't know why you are rushing, but I would wait for another month and get the correct fluid from MB.

What is your objection to driving to a dealer and buying the correct fluid?

I am trying to find aftermarket product that will do the job. Maybe it will help someone else in the future too. Also Fuchs is $30/L compared to $75. Idparts selling the kit.

https://www.idparts.com/differential...t-p-14738.html

Ok. That’s not an objection. What is your objection? Price?

I appreciate you helping me with the MB SPECS. Not sure why I have to object or be pro buying from dealer. I am only trying to source aftermarket. I prefer, If I can support local business/part store and not rely dealer.

So... instead of buying 3L of the Mercedes OEM fluid - the only one that you need and works in both diffs - you are instead going to buy 5L of three different fluids, INCLUDING 2L of the very same Mercedes OEM fluid from a third party because you don't want to buy it from a Mercedes dealer? :crazy: Yeah, really solid logic there dude.

ML550 Transfer Case Capacity with Off-Road Pkg?
 

I've seen the transfer case capacity is just over 1/2 quart of the ATF 134 (red), but I have an ML550 with the off-road package which comes with a modified transfer case (xtra low gear)...does anyone know what the capacity of this one is? Seems to be a rare option, so not much info out there on it. I ordered 1liter of Pentosin 134 (236.14 spec) and wasn't sure if that is going to be enough.

Your preference leads you to choose the wrong oil. Do you realize and agree with this?

BREAKINGBADLY: My dealer tells me my 2013 ML550 has no washers/o-rings for the front diff and xfer case drain/fill plugs, but you indicate the car DOES have those (and I can't find on FCP Euro or AutohouzAZ). Do you have part numbers, or purchase suggestions for these before I start this project? I'd rather not get stuck without replacement O rings and crush washers after breaking into this.

Be sure to verify the 550 requires sealing rings. The 350 4MATIC axles do not require sealing rings. Click on the DIY in my signature than on the front and rear axle fluid change.

ML550 differentials update. The front differential DOES have O Rings on the plugs, the rear one is just pipe thread. Also, since it is dual exhaust, to get to the drain plug for the rear diff, you must disconnect the muffler assembly hangers. I just sprayed with silicone spray lube, and they pushed out with a little force (screwdriver used as pry), same to put back on. The passenger side exhaust is in the way of the drain plug, but lowering the exhaust by disconnecting at the rear gives just enough space to get an extension in there. My unit has 60k miles on it, the front diff was a little dark...not terrible, the rear was in better shape, just barely darker than the new MB fluid. Probably could have gone another 25k miles no problem. Tackling the transfer case next. Looks like there is a heat shield attached to the Xfer case that has to be removed to get to the fill plug.

Finally got around to changing the transfer case fluid with Pentosin ATF 134. My ML550 with 2 speed transfer case/offroad takes 1.5 liters of fluid, not the 0.5 liters the normal case takes. The fill hole is behind the exhaust heat shield on the driver's side. Heat shield is just 4 bolts to remove. Drain is directly on bottom of the transfer case, fill is about 1/2 way up on drivers side (left) behind the heat shield. Again, for those of you with the 2 speed transfer case, it is a totally different design, and takes 3X the fluid...so make sure to buy 2 liters to have enough to do the job!