I counted on that when I changed my diff fluid. Didn't catch the distinction until after I did it.And I doubt either differential contains any brass or bronze parts.
I counted on that when I changed my diff fluid. Didn't catch the distinction until after I did it.And I doubt either differential contains any brass or bronze parts.
All it says on the BMW bottle is “75w”What is a straight 75W?? and does it even exist?
look at the https://bobistheoilguy.com/viscosity-charts/ and look at the range for the 75W block and then take a straight-edge and go to the left and you will see that a 75W ranges in viscosity from 4.2 cSt to about 7.2 cSt @100C; that's equivalent to an ATF range from a ULV to a Dexron III/Mercon viscosity range.
And that means nothing in terms of the actual viscosity, which is why an oil sampling must be done.All it says on the BMW bottle is “75w”
I’m also Curious how the redline mt lv fluid can satisfy 70w and 75wAnd that means nothing in terms of the actual viscosity, which is why an oil sampling must be done.
I'll give you the same information I gave MightyMouseTechI’m also Curious how the redline mt lv fluid can satisfy 70w and 75w
But here is the catch: A 75WWhat (75WXX??)? A 75W80, a 75W85, or a 75W90???mightymousetech said:
Apparently it is a 75W GL4. Luckily it is half the price of the factory rear diff fluid. LOL
I'll give you the same information I gave MightyMouseTech
But here is the catch: A 75WWhat (75WXX??)? A 75W80, a 75W85, or a 75W90???
We need to match the viscosity as close as we can because of the SAE gear lube ranges
could result in 100C viscosities ranging from 6.5 cSt to 23 Cst.
And once we can see the general chemical signature, we can match it up to what is already available.
You're still missing the point:hmm, ok Mola. Not knowing that, I would have assumed it was a straight 75
Redline said:MT-LV 70W/75W GL-4 GEAR OIL
- Popular in Toyota/Lexus LF 75W, BMW X-Drive and other transfer cases transfer cases calling for Shell TF0870
Shell calls it “transmission fluid”. It doesn’t mention “75w”. The BMW bottle, which is the Shell fluids says “SAE 75w”. I don’t know a lot about this, but I can email Redline and see if they can give any useful information.You're still missing the point:
Look at the 75W block and you will see it has a range of viscosities: https://bobistheoilguy.com/viscosity-charts/
The SAE grade really means nothing as you can have a range of viscosities for any grade so don't let the SAE XXW confuse you. It's the actual viscosity at 100C that is important, because this is where the minimum film thickness of the fluid was targeted in the gear and bearing design.
https://www.redlineoil.com/mt-lv-70w75w is in the middle of the 75W range with a 100C viscosity of 6.5 cSt
Here is the information they will give you:Shell calls it “transmission fluid”. It doesn’t mention “75w”. The BMW bottle, which is the Shell fluids says “SAE 75w”. I don’t know a lot about this, but I can email Redline and see if they can give any useful information.
Ok, I understand what you are saying now about the viscosity at 100C. I don't know much about transfer case fluids, so I might stick with the Shell fluid.Here is the information they will give you:
Like I said, don't get hung up on the SAEXX gear oil stuff and pay particular attention to the Kinematic Viscosity@100C.
The Redline MT- LV would give you a slightly thicker fluid film.If I were to go to Redline 70w/75w Mt-LV, is the Redline's 6.5 vs Shell's 6 viscosity at 100C much of a difference?
Thanks for the good info.
Thank you Mola! I think I will just use the Shell transfer case fluid, since it does not seem like many people have used the Redline MT-LV for BMW Xdrive transfer case. I would not have any proplem going aftermarket on transmission fluid. But it's still very weird that BMW specs 2 different 75w85s - 1 for front and 1 for rear. I don't know what year this went into effect.The Redline MT- LV would give you a slightly thicker fluid film.
+1Ya, OK. I would just use the Redline 75W90 front and rear (if you want the most protection), or 75W85 GL5 (if fuel economy is also a factor) and be done with it. I use all BMW fluids because, well, I have a gallon or so of each under my bench for free. They are good fluids though. No problem changing the viscosities in the diffs. The transfer case is a completely different animal though.
I have no idea why BMW calls for a GL4 in the rear diff, does seem odd.
Genuine BMW 75W85 G1 GL-4 Rear Axle Gear Oil - 500mL Bottle
Genuine BMW 75W85 GL-4 synthetic gear oil for 2012+ differentials without limited-slipwww.bimmerworld.com
It was changed late 2011.Thank you Mola! I think I will just use the Shell transfer case fluid, since it does not seem like many people have used the Redline MT-LV for BMW Xdrive transfer case. I would not have any proplem going aftermarket on transmission fluid. But it's still very weird that BMW specs 2 different 75w85s - 1 for front and 1 for rear. I don't know what year this went into effect.
Interesting. Redline told me 2016+ models went 75w85It was changed late 2011.
If your transfer case requires a fluid with a 6.X cSt viscosity@100C do you really think any fluid with a 12 cSt viscosity@100C would be appropriate?There are at least some 75W-85 gear oils that say both 'transfer cases and differentials'. Shouldn't these hence fulfill the needs of both the diffs front and rear and the transfer case?
RAVENOL MTF-1 SAE 75W-85
RAVENOL MTF-1 SAE 75W-85 is a PAO based full synthetic, low-viscosity transmission oil for special manual transmissions, transfer cases and differential ge...www.ravenol.de
RAVENOL DGL SAE 75W-85 GL-5 LS
RAVENOL DGL SAE 75W-85 GL-5 LS is full synthetic multi-grade hypoid transmission oil of API GL-5 power class with “limited slip” properties for manual tran...www.ravenol.de
Some owner manuals also don't have intervals for trans and diff fluids, some also say lifetime fluids. It's a classic bean counter vs engineer issue.read your owners manual, then obey it