[Noodles]

I just got the 85w90 at the dealer. I was not about to skimp on a $900 differential.
Some dealers have the 75w85 and MB had a release that it can be used and increase
fuel efficiency. I stuck with the 85w90 because I have a 4matic and I really doubt the
mileage increase would be all that significant on a 4matic.

It has been debated here before, but the shear strength of the wrong viscosity will shorten
the lifespan of a diff.

 

[Noodles]

The only approved gear oil I know that is below 80w90 weight for the W211 rear diff is
the MB 75w85 PN 001989330312.

I am not saying others won't work, but I am sticking to the book on fluid specs for our MBs.

 

[Noodles]

I would pony up for the MB 75w85. The Mobil 1 does not have an MB spec.
You will make the money back on better fuel mileage being that is an 85 and not 90 weight oil.
Part #001 989 3303 12

 

[Noodles]

I know MB has their fluids re-branded. I also get them at wholesale so I understand people trying
to save money. I believe Wolfgang's ML page had the same test/list.
There was a test posted at the ML Outpost about shear strength under heat and load and
the Mobil 1 75w90 did not pass the test. Maybe the new stuff is better, but IMO the risk
is not worth it.

 

[Noodles]

Thanks DB, I was going to search for those numbers you have posted many times before.
It just is not worth trying to save a few dollars on the fluid that can ruin a $900 part.

 

[Noodles]

My owner's manual calls for the 85w90. Is that because it is a 4matic?

Also I am aware of the 75w85 and agree that the MB fluid made for them by Fuchs is what
has been referred to in a MB service DTB. However I won't pit the the Mobil 1 in 75w90
in for reasons already listed and the warranty I have.

 

[Noodles]

I recently did the fluid on my transfer case and it was an ATF type fluid that was tinted
a light brown in color. MB part # 001 989 23 03 10. It is the only fluid the dealers are
putting in the W211 gasssers. It can be purchased in 1 or 5 liter bottles. No gear lube
is supposed to go in the transfer cases.
On the ML 430 the transfer case uses approved Mercon III ATF and in that I did use Mobil 1.

 

[Noodles]

Wow, that is a pricey dealer. Mine listed it of $27.13 and sold it to me for $23, but the
good news is you got some great fluid to keep the diff happy for years.

 

[Noodles]

I believe so, they will both work and are blessed by MB. I just stuck with what the owners manual said.

 

[Noodles]

Not sure it is the same on a W126.

 

[Noodles]

Which W211 do you have? The rear diffs are all the same on the 2 wheel drive models
as far as capacity, or so it says on the MB service DVD.

 

[Noodles]

Well I have real head banger here. I checked the fluid specs for a US spec car and
it said 1.3 liters. I wonder if the euro spec got a different differential.

 

[Noodles]

That looks like an additive.

You should just be able to use the MB 85w90 with no problems.

 

[Noodles]

No, the diff only holds less than $15 worth fluid.
Many techs and dealers still stick to the 85w90. It is the best protection for the gears.

 

[Noodles]

Odd, I got two bottles of the MB 85w90 for $18 apiece with my discount at the dealer.
It has gone up to $30 list. $120 is a bit on the high side. Why is the Fuchs so much more?

 

[Noodles]

I see the confusion. I used the A001 989 17 03 10 in the W211 and the W163,
It is in the MB chart from post 33. It still is approved for use.
It is not even in the MB chart in post 34.
I am familiar with MB's revision of the spec. I just wanted an approved spec that could be had
easily. Finding Titan here with shipping is an insane proposition.

 

[Noodles]

I guess I am lost, because as of Sept last year the A001 989 17 03 10 was still approved
on a chart that the dealer had that was printed in 2010.
If I have the wrong stuff in there obviously I am going to change it to the right stuff.

I just do not see in this image where the A001 989 33 03 10 is approved for the W211.
I do see the Mobil 1 approval in another image from post #34. They were out
of it at the local parts store. I live rurally, the dealer was the closest place.

 

[Noodles]

I am going with Drivbiwire on this. I am aware of the Mercedes bulletin that says the new
spec lube can be used, but in the ML and the E500 all diffs have been changed to the MB branded 85w90.
With 4000+ lb vehicles I would rather have the protection than the minute
fuel economy increase which was the primary reason MB put out the bulletin for the thinner lube.

 

[Noodles]

I knew somebody was going to post the bulletin.

We checked my diff gear # and it was 85w90 from the factory because it was a 4matic.
So when I did it I decided to keep it the same.
The rear diffs on the 4matics all got 85w90 according to the MB regional service manager
until the 2007 MY. The front diffs did also.
Also I had 4 liters on the shelf so I wanted to use it up. It is very hilly here and in the winter
the 4matic system gets a serious workout and I knew the 85w90 was not going to cause
any harm at all.

Like you I am not looking for a debate. We both know that MB has changed the acceptable
viscosity. The 85w90 is still on the approved list and is a more durable lube. Whether
or not it cuts down on wear over the lighter grade is something I may never know as
there is no set plan as to how long I am keeping the car. Actually shopping right now
for a diesel.