Posts by drivbiwire
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MB does not permit the use of anything less than 85w90 for US Spec cars.
(I hate repeating myself)
Straight from the US Spec manuals...
Rear differential:
1.06 US qt (1.0 l) Hypoid gear oil SAE 85 W 90
E 350
E 350 4MATIC
E 320 CDI
E 500
E 500 4MATIC
E 55 AMG*
*(MB Hypoid Gear Oil (85W-90)
MB Part No. A001 989 28 03 10)
Front Differential:
0.63 US qt (0.6 l) Hypoid gear oil SAE 85 W 90
E 350 4MATIC
E 500 4MATIC
Transfer Case:
0.62 US qt (0.585 l) MB Transfer Case Fluid
E 350 4MATIC
E 500 4MATIC
And wait they get thicker yet!
Hypoid Gear Oil
SL65 AMG (all model variants)
E63, SL55 AMG, CLS55 AMG, and CLS63
AMG equipped with AMG Performance
Package only
For rear axle differentials
Castrol SAF-XJ (75W-140)
(I hate repeating myself)
Straight from the US Spec manuals...
Rear differential:
1.06 US qt (1.0 l) Hypoid gear oil SAE 85 W 90
E 350
E 350 4MATIC
E 320 CDI
E 500
E 500 4MATIC
E 55 AMG*
*(MB Hypoid Gear Oil (85W-90)
MB Part No. A001 989 28 03 10)
Front Differential:
0.63 US qt (0.6 l) Hypoid gear oil SAE 85 W 90
E 350 4MATIC
E 500 4MATIC
Transfer Case:
0.62 US qt (0.585 l) MB Transfer Case Fluid
E 350 4MATIC
E 500 4MATIC
And wait they get thicker yet!
Hypoid Gear Oil
SL65 AMG (all model variants)
E63, SL55 AMG, CLS55 AMG, and CLS63
AMG equipped with AMG Performance
Package only
For rear axle differentials
Castrol SAF-XJ (75W-140)
Don't confuse the specs with Viscosity.
Because of varying climates that these cars are sold in MB WILL require for certain regions a high viscosity range WHILE requiring compliance with a certain specification. Also certain regions will have different components that may/will require different viscosity ranges.
In the US the first and most important specification is the viscosity range THAT complies with the MB 235.0 and MB235.7 technical standards. Yes there are thinner fluids that comply however those fluids ARE NOT permitted for use in specific regions and specific applications.
Again in the US markets nothing thinner than 85w90 may be used that complies with MB235.0 and 235.7 standards.
Because of varying climates that these cars are sold in MB WILL require for certain regions a high viscosity range WHILE requiring compliance with a certain specification. Also certain regions will have different components that may/will require different viscosity ranges.
In the US the first and most important specification is the viscosity range THAT complies with the MB 235.0 and MB235.7 technical standards. Yes there are thinner fluids that comply however those fluids ARE NOT permitted for use in specific regions and specific applications.
Again in the US markets nothing thinner than 85w90 may be used that complies with MB235.0 and 235.7 standards.
No its for the MB spec'd 235.7 85w90. In the US 85w90 is not sold or available on the market since the majority of car makers do not require the higher viscosity fluids.
85w90 is a synthetic...it is produced by Mobil/BP/Castrol for Mercedes List is around $30 per liter, if they cut a deal it can be had for around $26.00. This is a high end synthetic not a conventional lube which is why MB is using it on more and more applications becuase of its better protection to the differentials.
In the US we pay about 1/2 the price for lubricating fluids.
The critical operating temperature is 40C for a differential.
75w90 is does not provide sufficient protection in most MB applications.
NEVER use a 75w90 in a US Spec differential.
In the US we pay about 1/2 the price for lubricating fluids.
The critical operating temperature is 40C for a differential.
75w90 is does not provide sufficient protection in most MB applications.
NEVER use a 75w90 in a US Spec differential.
Your information was current back in 2002...it has since been revised (2/2007)!
Go ahead and run a differential fluid that is 30% thinner than the 85w90 which MB now calls for in 2006-2010+.
Viscosity is the key factor, the 75w90 and 75w85 is simply to thin for the differentials. The 75w90 is only called for in the G and R class differentials WITHOUT limited slip, if you have limited slip we go right back to viscosity ie 75w140!
MB has revised that recomendation to only include 85w90 as the primary viscosity range and no longer supports the thinner fluids.
The higher the 40C cSt the better the fluids performance in typical operating temperature ranges.
To quote the STLE mantra "Viscosity, Viscosity, Viscosity!"
Given that all my Mercedes are Diesel, the increased torque going thru the gear boxes is quite a bit higher than that in a gasser. I need a higher viscosity fluid to protect the gear sets and bearings (just as Mercedes recommends).
All the BS aside, I replace the differential fluid with every transmission fluid flush ever 30,000 miles.
Below are all the current supporting documents.
Go ahead and run a differential fluid that is 30% thinner than the 85w90 which MB now calls for in 2006-2010+.
Viscosity is the key factor, the 75w90 and 75w85 is simply to thin for the differentials. The 75w90 is only called for in the G and R class differentials WITHOUT limited slip, if you have limited slip we go right back to viscosity ie 75w140!
MB has revised that recomendation to only include 85w90 as the primary viscosity range and no longer supports the thinner fluids.
The higher the 40C cSt the better the fluids performance in typical operating temperature ranges.
To quote the STLE mantra "Viscosity, Viscosity, Viscosity!"
Given that all my Mercedes are Diesel, the increased torque going thru the gear boxes is quite a bit higher than that in a gasser. I need a higher viscosity fluid to protect the gear sets and bearings (just as Mercedes recommends).
All the BS aside, I replace the differential fluid with every transmission fluid flush ever 30,000 miles.
Below are all the current supporting documents.
Attachments
So what does a 1997 Supra have to do with a Mercedes Benz topic and 75w90?
The fact remains that only the viscosity range of 85w90 is approved unless otherwise stated for your model.
The MB235.7 85w90 is a synthetic oil
MB Hypoid Gear Oil (85W-90)
MB Part No. A001 989 17 03 10
If you want to trash your differential go for it.
I am simply recomending what Mercedes recomends ie 85w90 and if you had any clue as to why, it would be obvious that a 75w90 is too thin for these applications.
Would you run a 0w20 in your Mercedes engine, thats the difference in viscosity we are talking here when comparing a 75w90 to an MB235.7 85w90.
The fact remains that only the viscosity range of 85w90 is approved unless otherwise stated for your model.
The MB235.7 85w90 is a synthetic oil
MB Hypoid Gear Oil (85W-90)
MB Part No. A001 989 17 03 10
If you want to trash your differential go for it.
I am simply recomending what Mercedes recomends ie 85w90 and if you had any clue as to why, it would be obvious that a 75w90 is too thin for these applications.
Would you run a 0w20 in your Mercedes engine, thats the difference in viscosity we are talking here when comparing a 75w90 to an MB235.7 85w90.
It depends on the model, some require a thicker fluid ie 75w140 so yes "Unless otherwise stated" because the higher performance models need a thicker fluid.
The issue again is the 85w vs the 75w and that the 75w has 1/3 to 1/2 the viscosity at 40C when comparing to the 85w under the MB235.7 fluids.
The fact is the Manual says that you are wrong, so if you choose to use the incorrect fluid thats your choice.
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The issue again is the 85w vs the 75w and that the 75w has 1/3 to 1/2 the viscosity at 40C when comparing to the 85w under the MB235.7 fluids.
The fact is the Manual says that you are wrong, so if you choose to use the incorrect fluid thats your choice.
You're Clueless....
The 0w40 offers the same protection as a 15w40.
However a 15w40 CANNOT protect as well as a 0w40 especially in a cold climate.
Each number has its own meaning in respect to how the oil will flow and ultimately protect.
For most engines made by Mercedes a 5w40 offers the best all around protection. The 0w40 is an ideal oil for those that live in areas with a wide range of temperatures.
The 0w40 MB229.5 will continute to protect at temperatures as high as +400F where a conventional 15w40 will fail at around +265F.
A 15w40 will not flow at all in the sub-zero conditions where the 0w40 will continue down to -50. This translates into faster oil pressure and quicker protection to the motor.
When given a choice, a 0w40 wins everytime.
Attachments
The MB (dealer) 85w90 has 50% higher shear strength than the Mobil 1 75w90 at 40C.
40C is the typical operating temperature of a differential in most conditions.
75w90 = 99 cSt @40C
85w90 = 153 cSt @40C
If you have to ask, higher value is better.
The viscosity trends downward and both are equal at 100C, however 100C isn't a temperature the differential will ever see.
MB as of the latest guidance in the W211 does NOT want the 75w90 used especially in the Diesel applications...for obvious reasons (torque).
40C is the typical operating temperature of a differential in most conditions.
75w90 = 99 cSt @40C
85w90 = 153 cSt @40C
If you have to ask, higher value is better.
The viscosity trends downward and both are equal at 100C, however 100C isn't a temperature the differential will ever see.
MB as of the latest guidance in the W211 does NOT want the 75w90 used especially in the Diesel applications...for obvious reasons (torque).
After driving for about 1.5 hours (50% highway 90mph, 50% city stop and go) I measured the differential temperatureIsstay said:
Drum roll......
47.5C (82F outside air temperature)
If your differential is running hot it's probably due to the wrong viscosity driving up the shear and friction in the gear sets.
FWIW I took a sample of the fluid when I drained it from my differential and it came back as an 85w90 within a few cSt of the factory claimed specs (153 cSt).
Also, depending on the design of the final drive you could in theory build it to use a 0W oil, however due to size constraints the loads on the individual gears goes up thus requiring a higher viscosity range.
A large truck could probably get away with a 75w90, but the differential in an MB being 1/10th it's size and handling 30-40% of the same torque cannot.
Again, the fluid called for in my service sheets on my 2006 W211 CDI all call for ONLY the 85w90.
Now, if you live in Europe where you have a much lower ambient temperature than we do here in the US, the 75w90 may very well be suitable. However with higher average temperature ranges the requirements for higher 40C viscosities are mandated.
Also worth noting, this is why in the US 5w30 (or worse 0w30) viscosity ranges are NOT approved, again due to the climate exceeding the safe operating temperature ranges they are intended for.
For the 85w90, MB uses a very high end synthetic base stock to achieve the lower pour point and still retain the higher temperature shear strength.
From Fuchs, the current specification and viscosity ranges for 2011:
MB-sheet Application area
MB 235.0 Hypoid gear oils SAE 85W-90, SAE 90
MB 235.1 Gear oils SAE 80, 80W/85W
MB 235.4 Synthetic gear oils SAE 75W/85W
MB 235.5 Gear oils SAE 80, 80W/85W
MB 235.6 Hypoid gear oils SAE 85W-90, SAE 90
MB 235.7 FE-hypoid gear oils SAE 85W-90
MB 235.8 Hypoid gear oils SAE 75W-90
MB 235.9 Axle oils for ZF automatic transmissions
MB 235.10 MTF
MB 235.11 FE-MTFs for extended drain intervals
MB 235.12 Manual gearbox oils SAE 30, 40
MB 235.13 Fully-synthetic manual gearbox oils
MB 235.15 Hypoid gear oils SAE 75W-85
MB 235.20 Mineral axle oils, LD, SAE 80W-90
MB 235.27 Retarder oils NFZ, category voith A
MB 235.28 Retarder oils NFZ, category voith B
MB 235.29 Retarder oils NFZ, category voith C
MB 235.61 Hypoid gear oils, AMG
MB-sheet Application area
MB 235.0 Hypoid gear oils SAE 85W-90, SAE 90
MB 235.1 Gear oils SAE 80, 80W/85W
MB 235.4 Synthetic gear oils SAE 75W/85W
MB 235.5 Gear oils SAE 80, 80W/85W
MB 235.6 Hypoid gear oils SAE 85W-90, SAE 90
MB 235.7 FE-hypoid gear oils SAE 85W-90
MB 235.8 Hypoid gear oils SAE 75W-90
MB 235.9 Axle oils for ZF automatic transmissions
MB 235.10 MTF
MB 235.11 FE-MTFs for extended drain intervals
MB 235.12 Manual gearbox oils SAE 30, 40
MB 235.13 Fully-synthetic manual gearbox oils
MB 235.15 Hypoid gear oils SAE 75W-85
MB 235.20 Mineral axle oils, LD, SAE 80W-90
MB 235.27 Retarder oils NFZ, category voith A
MB 235.28 Retarder oils NFZ, category voith B
MB 235.29 Retarder oils NFZ, category voith C
MB 235.61 Hypoid gear oils, AMG
Oil can shear out of grade and have absolutely no change in terms of color or clarity.
As a rule of thumb gear oil in low stress applications will last about 100K. Higher stress applications such as MB (Diesels, V8's, AMG, SUV etc) will shear much quicker, hence my recomendation for changing the 85w90 every 30K with the transmission fluid. I consider it cheap insurance for the $40 it costs to service.
DB
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