If anyone is interested, this showed up at my doorstep today:

I ordered it many months ago when we first began this thread and I guess it just arrived in stock. Not sure about worldwide availability, but the 235.63 gear oil is now shipping in the US. Interestingly, it is listed as "transmission oil" online, but my bottle clearly states "differential gear oil."

 

To serve as a reference, the Magna unit in the RS3 and Golf R appear to be identical, down to the case design, internals, control units and mounting points:

The Magna unit for MB seems to have been put together slightly differently (I'm assuming for packaging considerations) with the most obvious being a different case design, different mounting points, and the passenger-side control unit is clocked differently.

So whether or not they all use the same oils for the gear sets and clutch packs, I don't know (but I strongly suspect the internals are nearly the same, if not identical). One additional thought: even if the internals are identical, different programming of the units by Audi, VW & MB to illicit different behaviors may very well necessitate different operating fluids.

 

Can I ask what the A35 unit is and, if VW can offer the same for the Golf R/S3 and the RS3, why can't MB.

 

@Theo without checking, I’m pretty sure the front diff is part of the gearbox lube. So no separate maintenance.

Re centre section, personally I would go with a Hypoid GL-5 oil, with viscosity as close to the OE spec. I personally don’t like the idea of the .15 oil, in a set of Hypoid gears. Hypoid gears require Extreme Pressure oils.

 

Not sure if I read this table correct but it seems our front diff should take 235.74 or 235.0 oil?

And the DCT needs 236.22 ?

 

Thanks for the heads up.

Seems like the 235.63 is now widely available. That was fast, only took them four years after the first M139's hit the market.
Here's mine, luckily only took a couple of days to arrive as I ordered it last week. It's same batch as yours too.

The BMW oil has served its purpose, being the closest available alternative. Ran it for 2-2.5k miles, but it's time that the diff gets the oil that was meant for it. Booking an appointment for next week, together with an engine oil change, my usual AMG 0W-40, which I've been purchasing online since last Spring (6-month oil changes), as it's no longer available at the dealer.

 

Thanks I read the other thread…cars going in Friday🤞

 

Car collected, apparently the software adaptions completed at the end of the service hadn’t been completed successfully causing the issue…I was assured the axle had been re-serviced with fresh fluids, the test drive and drive home have been completed without incident, noises or tyre grabbing 🤞

 

According to my list:

Rear Diff:
Gear set - M-B 235.63 - not in service schedule, "lubed for life" 😂
Coupling - M-B 235.64 - A0009894406
No diff filter. Left and Right coupling separate fills.



Gearbox (I'm not 100% sure of the parts below, so check with your dealer):
Filter - A2463772300
O Ring - A0229978045
ATF - M-B 236.22 - A0009896104

 

Ok so I picked up 6lt of ATF - M-B 236.22 - A000989610409 and I was told it takes up 5.something.

Now on to the diff left and right section oil, DCT filter etc, and plugs... and let the wait begin (hope not).

 

For anyone interested, I'm attaching the oil level check and change procedure from erWin for the Golf R unit. Other than the resetting the oil adaptation values with diagnostic software, it appears to be a pretty straightforward procedure on the VW.

 

75w80 Synthetic Gear / Diff Oil GL-5

Fully Synthetic 75w80 Premium Gear / Differential Oil Fully synthetic gear oil is a high performance product manufactured from a blend of synthetic oils, sheer stable viscosity index improvers and a multipurpose extreme pressure additive system. It offers a high level of performance when...

www.westwayoils.co.uk

 

veeeight,

Can you articulate your reasoning for recommending a GL-5 oil vs. GL-4 for this application (most 75W80 oils I've come across are GL-4 spec)? Just curious as I see Westway Oils offers their 75W80 in both specifications. Thanks!

 

Picked up a few things that arrived recently, don't really know when, I didn't get a call as I explicitly requested. Perhaps they didn't think I needed it, as I ought to have upgraded myself to the 6th sense. So I called them instead.

The little box is listed as the oil cooler filter and the bigger ones as oil filters.
The little o-ring on the left is listed as an o-ring seal (profile) and the bigger ones as o-rings.

And now we come to what really worries me, the diff oil. As you can see they gave me the 235.15 approval which, as I've been reading here, is not the right one for our twin clutch system. I looked in the bag just to make sure, and I immediately asked why it's not the 235.64 which is the right one based on what I've read. They went like "where did you find that info" typical dealership response like I'm some dumbass clueless rich dude owning a six figure car, not supposed to worry about anything going into the engine and other components, and I said "from owners in the UK, that's the one they use". Guy said, "so that's what they use in the UK, it's country-specific". I said, so how come we use the same engine oil 0W-20, no matter if I have personally decided to stick to the AMG 0W-40 as I would use the 20 to boil my spaghetti in our blazing hot summer, the 0W-20 is still the recommended one, which is the same in both countries. So same engine oil but we use different diff oil? doesn't make much sense. He said he would run another check based on my VIN, but I don't think that is going to change anything as all orders are based on VIN in the first place. Perfect...

I have sent MB an inquiry, asking which is the right diff oil approval for my car and in my region.
Waiting for their response.

 

@veeeight so the 235.15 that they gave me is for the single clutch differential systems, not suitable for our twin unit.

 

I have given up trying to second guess why dealers give out the parts/lubes they do! No idea why they thought 235.15 was correct for your car. Unless they have an instruction that says substitution is OK…….


M-B 235.64 is Shell TF 0870 B - which if you look at the description - is approved for Magna Powertrain:

Shell TF 0870 B 209 Liter

<strong>Shell TF 0870 B</strong><br /> Synthetisches Verteilergetriebeöl<br /> <br /> Shell TF-0870-B ist ein Hochleistungs-Getriebeöle für spezielle Verteilergetriebe von Magna Powertrain und Mercedes-Benz Hinterachsgetriebe nach MB 235.64

www.kreissler24.de

 

It's not ideal the situation we collectively find ourselves in around this lubricant situation. I'm guessing from @fatty45, response to my diff oil MB used, it is not necessarily exactly correct but it's not possible to tell for sure but it's generically possible it is correct.

I would be interested in @Turbo Ed experience on this in Australia. Or have I missed it in the size of the post

@Forrester et al

The only reason I have not been involved in this discussion recently, is that I thought I made my views clear, posts ago.
To reiterate and add slightly.
1) Never believe OEM's so called "service recommendation intervals".
2) OEM Dealerships in this country at least, are staffed by individuals who could not / can't get a job in the quality independent service industry.
3) After first service, (whenever that is specified) my vehicles are always serviced at quality independents, depending upon the brand. (In this country, they tend to specialize)
5) I specify the change intervals, brand and grades of lubricants used.
6) I use a local lubricant supplier where I can, as they have almost 100 years' experience in one of the world's harshest lubricant environments.
7) I have used their GL-5 (as @veeeight has been stating repeatedly) in the hypoid ring gear section of the rear axle assembly of all my vehicles for many years.
8) The two side clutch packs in our rear axle assembly are relatively rare in this country.
If you added all the MB and VAG variants using this tech here, I doubt it would total 1000 vehicles.
Consequently, the local lubricant supplier, at least the last time I checked, had not released their version of 235.64.
Which, again as @veeeight has been repeatedly stating, is the correct MB spec. for the side clutch packs and as far as I can see, for worldwide usage.
So, my independent workshop purchases the side clutch pack lubricant, (usually without trouble I should say), from our local MB dealership, which by pure coincidence is also from where the vehicle was sold.

Now, like @veeeight, I am also out of here.

 

Guys,

OK I think we are all in agreement that obtaining the correct lubricants for our rear axle assemblies through the MB Network is problematic, at best.

So, I have been spending recent days talking to Magna, (who, incidentally, claim our assemblies were designed and are built in a different Magna facility to the VAG products, however who really knows, outside Magna) and then to various large European lubricant suppliers, on the basis my local Australian specialist lubricant supplier is of no use to most of you.

So, firstly the rear axle differential oil; MB reference 235.63 This should be GL-5 rated SAE spec 75W-80 oil, in my opinion a full synthetic. (Some companies claim to meet the spec with a partial synthetic). Many large European companies offer this oil as a full synthetic; however, the company with the widest distribution, literally across the world and therefore of the most use to all members here, is the German company FUCHS. So best to start there.

Then, the unique, (as far as I can tell) to our vehicles, the side clutch pack oil; MB reference 235.64.
According to Magna, this IS different to the VAG spec.
Both the oils apparently are only made by SHELL.
I cannot swear to this, given the number of specialty lubricant manufacturers in the world.
However, if we are talking a true muti national lubricant distribution system, so everyone here can use the info, I think SHELL is it.

Shades of the Spark Plug fiasco.

The VAG product supposedly uses SHELL's TF 0870

Our vehicles use SHELL's TF 0870 B
The difference apparently all being in the B.
Now, I am not saying your local SHELL distributor will have it on the shelf; however, they SHOULD be able to order it in for any of you.

Like I say, really reminds me of the Spark Plug scenario.
For a "mas produced" vehicle, our cars are unique in so many areas it is really quite extraordinary.

No wonder the typical MB Dealership Workshop / Parts Dept are completely out of their depth.

 

Their product is called Titan Sintofluid 75W-80.

@Turbo Ed - I would have thought something from their Sintopoid Hypoid range would be more suitable?

 

All,

I finally got my ISPPI (the new EPC) account ironed out and I'm able to login. I can confirm the following MB part numbers for the TWIN rear axle:

for hypoid chamber (235.63): A0009893608
for clutch packs (235.64): A000989440611 CDNW
drain/fill plugs (they list 4 required but add two more if also replacing the hypoid chamber oil): A1779901100

now if we could just find the procedure...

 

@fatty45

I recall seeing a procedure in WIS for changing the oil in the 2 side clutch packs. No need to replace plugs etc. No mention of any diagnostic reset etc.

There is however no procedure for changing the centre gear section oil but anyone with any mechanical sense should be able to work that section out.

 

@fatty45

I recall seeing a procedure in WIS for changing the oil in the 2 side clutch packs. No need to replace plugs etc. No mention of any diagnostic reset etc.

There is however no procedure for changing the centre gear section oil but anyone with any mechanical sense should be able to work that section out.

@veeeight, I have access to two instances of WIS, mid-2021 and late-2022 and neither lists a procedure for changing the clutch oil, but both reference it being required on the maintenance schedules. I have checked both the c118 and w177 sections without luck. If you're able, could you post a screen-shot or excerpt covering the procedure?

 

OK, checked with my independent workshop, who, after me discussing it with the Owner, then proceeded to repeat it to his entire workshop staff, with much merriment, all round.
I think I was the light relief for the day.
As I suspected, the reason they have never mentioned anything about the job to me previously, is that it was simply not worth mentioning, at least in their eyes.
Just another simple maintenance task.

 

What if we use the 235.15 for the center section, if we can't find the aftermarket 235.63? The difference is minimal, 75W-85 vs 75W-80 and while it would be smart to get it spot on for the clutch housings, perhaps a slightly thicker oil such as the 235.15 for the center gear set might work just as well. So 235.64 for the two clutches and 235.15 for gear set?

I'm asking because so far I haven't found the 235.63 (see post #208 first two paragraphs) and I have already purchased the 235.15. Have already ordered the 235.64 from dealership.

 

Almost DIY time!

 

"transfer case" or "haldex" or however the unit which transfers the power between the front and rear is called (or is this the what is meant above with the lubed for life "gear set"?)

W177 A45s works differently from the single Haldex/Borg Warner type electronic multi plate clutch in the sense that the single clutch pack connecting front and rear does not exist - instead 2 multi plate clutch packs are installed, one on each half shaft exiting the rear diff, to control each side locking or slipping independently. This is how you can engage one side more than the other giving drift mode.

So the centre section rear diff is conventional hypoid diff gears (“lubed for life”) and the 2 side clutch packs require oil changes with Shell TF 870 B.

 

Does this mean that the clutch packs on each rear wheel not only control the torque "left to rear" but also "front to back" 🤯 ?

 

Just picked up the final parts for the whole service, the 235.64 oil and the gasket seal for the gearbox.

So guess what arrived today, 1 liter of Shell TF 0870 B. The one we've been talking about, except I got it from the dealership, so apparently that's the one MB provides as 235.64. Wasn't expecting that. Also got the rubber gasket seal for the gearbox, so I'm finally ready for the complete, as per MB schedule, diff and gearbox service, but still need to decide what to do with the 235.63, which, frankly, I might just skip for now, as I'm not sure I've found the right oils.

And I picked up 6 liters of AMG 0W-40 but I had to find another source as it has been discontinued by the local MB distributor. Dealership now only provides the Petronas 5W-40, which I wouldn't hesitate using, but prefer the AMG which I've been running since the first oil change. Got the oil filter too, just because they said they only had 5 pcs left.

 

@Theo,

The Shell TF0870B is what is supplied, in Shell packaging, by MB Australia, also, so I am guessing it is a worldwide scenario.
It simply shows the low volume nature of our vehicles, in that it is not worth MB / AMG's while to even bother with re packaging, as they would do for the more commonly used lubricants.

 

Well team, I went ahead and did a DIY Service B with rear differential service today. While I had the belly pan off for the oil filter, I noticed a small transmission fluid leak towards the back, but that adventure will be the subject of a different post. My question today deals more with the resetting of the oil condition post-clutch pack servicing.

I drained and filled both sides with the prescribed Shell TF-0870B and 1 liter was just enough to fill both sides to overflowing. I was surprised at how dark the fluid was as compared to new. I fired up Xentry and the multiplexer to perform the computer reset. I selected the right hand clutch pack computer first - adaptations - teach-in - reset oil service. It walked me through the procedure: oil above 86F? - start the car - stop the car - ignition on - ignition off - etc. until "successfully reset" came up. Super easy and intuitive. It then stated to repeat with the left clutch. So I called that computer up, ran through the same process, and right at the end, Xentry would say something like "module declined to respond to command." I repeated the reset from the beginning 3 times with the same result. No drivability issues detected during the test drive.

I seem to remember reading somewhere that one side's computer acts as the "master" for certain functions - I wonder if that's why the oil condition reset was only possible via the right hand computer. Does anyone have any experience with this or ideas?

 

Well team, I went ahead and did a DIY Service B with rear differential service today. While I had the belly pan off for the oil filter, I noticed a small transmission fluid leak towards the back, but that adventure will be the subject of a different post. My question today deals more with the resetting of the oil condition post-clutch pack servicing.

I drained and filled both sides with the prescribed Shell TF-0870B and 1 liter was just enough to fill both sides to overflowing. I was surprised at how dark the fluid was as compared to new. I fired up Xentry and the multiplexer to perform the computer reset. I selected the right hand clutch pack computer first - adaptations - teach-in - reset oil service. It walked me through the procedure: oil above 86F? - start the car - stop the car - ignition on - ignition off - etc. until "successfully reset" came up. Super easy and intuitive. It then stated to repeat with the left clutch. So I called that computer up, ran through the same process, and right at the end, Xentry would say something like "module declined to respond to command." I repeated the reset from the beginning 3 times with the same result. No drivability issues detected during the test drive.

I seem to remember reading somewhere that one side's computer acts as the "master" for certain functions - I wonder if that's why the oil condition reset was only possible via the right hand computer. Does anyone have any experience with this or ideas?

Dealer did it exactly as you described. Mechanic went to download the relevant Xentry instructions (he also handed me a printed copy of it, which shows something interesting about the oil, I'll post in a few days) and started draining the two sides. Oil came out dark as you described, except for the center section that he did next, which looked like new, nice and amber - does it even do anything?

It's been a while since, it was before it warmed up over here so maybe that's why it went smooth without problems.

Quantities... as you said, 1 liter of Shell TF-0870 B was just enough to fill both sides to overflowing.

Center section took the whole 500ml of BMW G4, 75W80, hypoid GL-5 and a little of a second 500ml bottle I provided them for peace of mind, in case they spilled any, and I'm glad I did. Didn't purchase a spare Shell bottle but luckily I didn't need it, guess I'd better purchase two of each next time. Also worth noting, while the side clutchpacks procedure included the screw torque, there was nothing on the center section, so I trust he knew what he was doing - so far no problems anyway.

 

And once more I'd like to thank you for finding the BMW oil alternative. Your contribution was valuable for those who decide to change that out too. Big thumbs up man!

 

Thank you to everyone! I now look forward to doing this service myself soon with confidence. Special thanks to @veeeight and @fatty45

 

There is a YouTube video of a guy doing his rear diff on his a45s. KHAN performance. Does a step by step video.