[ezzo]

I realized that I had put the wrong oil in my two differentials. I used RedLine MT-90 which is a GL-4 specification and not suitable for hypoid gears in teh differentials. From the RedLine website (https://www.redlineoil.com/mt-90-75w90-gl-4-gear-oil):

MTL, MT-85 & MT-90 are not for use in differentials with hypoid gear

I did not know the difference between GL-5 spec oil (required for hypoid gears) and GL-4 spec oil (required for gears with synchros) until I did more research.
So, I figured this is a good flush for the old fluids and I should just replace them again. I went through the painful process again yesterday and replaced the GL-4 with MB hypoid gear oil, part number 001 989 33 03 12 ($53/bottle) which is 75W85 (the dearler here does not sell the 85W90 required in my user manual!)

I posted the whole procedure here:
http://www.benzworld.org/forums/w21...-front-diff-oil-change-dark.html#post17362706

 

[Noodles]

The 75W-85 actually is approved and MB has a bulletin that it is fine to use in place of the 85W-90 weight.

 

[ezzo]

Thanks for your reply, @Noodles. I agree with you. I wanted to use 75W90 because it is not as thick, but I could only find GL-4 spec 75W90, not the GL-5 spec for the differentials. Maybe after a year or so, I can change the fluid in both differentials again.

 

[Noodles]

I do mine every 40k miles. I had no idea they were getting it for $53 per bottle in Canada for it.

 

[philipz]

@ Ezzo :

Any update regarding the noise ?

Just so you know , i`ve used the original MB 85w90 hypoid gear oil ( on both diffs) , also the approved Fuchs Sintopoid 75W85 ( on the rear diff ),but flushed it with the MB fluid right after . Flushed twice the TC with the original MB fluid . No result there , the whining is still there .

My mechanics are suspecting this part : A 211 410 01 81 . Its the rear propeller shaft bearing . But they told me that it is too soon to tell , the noise needs to get louder , so they can hear it while under the car .

 

[ezzo]

@ Ezzo :

Any update regarding the noise ?

Just so you know , i`ve used the original MB 85w90 hypoid gear oil ( on both diffs) , also the approved Fuchs Sintopoid 75W85 ( on the rear diff ),but flushed it with the MB fluid right after . Flushed twice the TC with the original MB fluid . No result there , the whining is still there .

My mechanics are suspecting this part : A 211 410 01 81 . Its the rear propeller shaft bearing . But they told me that it is too soon to tell , the noise needs to get louder , so they can hear it while under the car .

Thanks for the update. I used MB original diff fluid for both front and rear, and original MB fluid for the TC.
I used the procedure @ps2cho posted here http://www.benzworld.org/forums/w21...ansfer-case-fluid-change.html#/topics/2336329

Unfortunately, I still have the same noise. @jaru1 explained in post #28 on this thread http://www.benzworld.org/forums/w21...innng-me-new-post.html#/topics/1570830?page=3 that there is an inherent problem in some bearings. It could be the samepart that you posted.

 

[ot1]

What i would do is put the car up on 4 jack stands, attempt to duplicate the sound at whatever mph, have the driver window down so your helper can hear you, figure out if its really coming from the rear. Pull the diff covers off to look for metal. I have NOT had a mercedes diff apart but likely there will be a magnet to catch debris. BE VERY CAREFUL, ESPECIALLY OF THOSE MOVING TIRES!!! DON’T HAVE SOMEONE DEAF BEHIND THE WHEEL! If you have access to a lift even better, but due to insurance they might not allow it to be put in gear. USE EXTREME CAUTION!

 

[jrobbins70]

I recently had the rear diff oil changed on my E63 and the dealership sold me Castrol Syntrax Limited Slip 75w-140. The diff held 1.2 liters and cost me about $40 USD in fluid.

Is this special stuff because it's an AMG? I am reading plenty about 4matics etc using 85w90.

J

 

[Noodles]

Some of the AMGs do use a different spec for the the diff. In your case the LSD does list the Castrol XJF 75-140 as the correct fluid.

 

[NewShockerGuy]

I don't want to beat a dead horse. My mind is somewhat blown from reading all 9 pages when I thought in all reality while I am changing my transmission fluid I might as well change the rear diff fluid, thinking this would be a straight forward answer to find that one needs X weight and it's done.

I have a 2009 e350 NON-4matic.

I want to buy two liters of rear diff fluid. I AM 100% fine buying OEM MB fluid.

Seems like I would have two options below?

A001 989 33 02 12 : 75w-85
75W85 Gear Oil - Genuine Mercedes 001989330312 | FCP Euro

or

A001 989 17 03 10: 85W-90
Amazon.com: Genuine 001989170310 Mercedes 001 989 17 03 10 / Oil: Automotive

I live in VA and will not be driving this car during the winter months at all. Fall/Spring/Summer here and there..etc.

Sorry to bring this back but my mind hurts from trying to figure out what is correct and or what should be used as both sides tend to be strong in which fluid should be used.

Also do we have a part number for the two fill/drain plugs on the rear diff. I read somewhere or watched a video that said they should be replaced for new. Is this the correct part number for both plugs: 3529970032


Thanks much,
-Nigel