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Where does it say in the owners manual to change dif fluid?
Redline 75w85 for BMW
- Thread starter BMW Dom
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then why you asking
Then give it a shot, not my money.
But if you start feeling shuddering when taking sharp turns in parking lots, it is too late.
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I use the owner's manual as a guide. According to my owners manual "Have oil changed only at your BMW center or at a workshop that works according to BMW repair procedures with correspondingly trained personnel"
You also consider the fluid specifications and approvals as a guide?
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I use ll-01 oil and Mann oil filters. I haven't changed the other fluids yet. But I don't know if I want to pay $110 a liter for
That is not the front differential, you are talking about the transfer case. They are two different parts.
Actually now you have me confused, which are you talking about, the transfer case or the front diff?
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Sorry for the confusion. The rear differential fluid is $110 liter. I think I have myself confused too.
Ya, 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.Sorry for the confusion. The rear differential fluid is $110 liter. I think I have myself confused too.
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-slip
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You must be lucky to have access to all of those fluids! Thanks for the info
MolaKule
Staff member
I see. Transfer cases have a different gearing system so a GL-4 should be sufficient.
What does the Owners manual state with respect to these three fluids since I am guessing we are now discussing three fluids: 1) the front differential, 2) the Transfer case, and 3) the rear differential?
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The owner's manual doesn't mention any of them. The manual only says what oil approval to use.
What BMW ETK calls for:
1) front diff: G2 gear oil (75W85 GL5)
2) transfer case: DTF 1 Transfer box oil
3) rear diff: G1 gear oil (75W85 GL4)
MolaKule
Staff member
I have to agree with MMT and use a 75W90 GL-5 in both front and rear differential and be done with it.
Now, for the transfer case, I would take a sample and send it off for analysis so we can attempt to match it up with something in which we already know the chemistry and viscosity.
Now, for the transfer case, I would take a sample and send it off for analysis so we can attempt to match it up with something in which we already know the chemistry and viscosity.
Apparently it is a 75W GL4. Luckily it is half the price of the factory rear diff fluid. LOL
MolaKule
Staff member
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 the SAE gear lube ranges
Viscosity Charts - Bob is the Oil Guy
Viscosities can be related horizontally only Viscosities based on 96 VI single grade oils. ISO are specified at 40°C AGMA are specified at 40°C SAE 75w, 80w, 85, 5w, & 10w specified at low temperature. Equivalent viscosities for 100° & 210°F are shown SAE 90 to 250 and 20 to 50 specified at...
bobistheoilguy.com
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.
Apparently straight 75W.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 the SAE gear lube ranges
Viscosity Charts - Bob is the Oil Guy
Viscosities can be related horizontally only Viscosities based on 96 VI single grade oils. ISO are specified at 40°C AGMA are specified at 40°C SAE 75w, 80w, 85, 5w, & 10w specified at low temperature. Equivalent viscosities for 100° & 210°F are shown SAE 90 to 250 and 20 to 50 specified at...bobistheoilguy.com
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.
There is some confusion as to whether it's GL4 or GL5 for the rear diff. There is a different part number for cars after 07/2011. Bimmerworld is the only vendor where I found this distinction in their parts listing. The strange thing is the differential is the same part number regardless of year. One is a 75W85 and the other is a 75W90 but that to me is much less important than GL4 vs GL5 because of the way the two spec 'play' with certain metals.
The above is in reference to my E82 - assuming the same for the E90.
The above is in reference to my E82 - assuming the same for the E90.
MolaKule
Staff member
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.
MolaKule
Staff member
And I doubt either differential contains any brass or bronze parts.