Hey guys, I was looking through my manual for my new 2017 F150 & noticed that Ford now says to use 75w-85 Gear Lube in both the front & rear diff. This is seems to be a drastic switch from the once required 75w-140 in the rear & 80w-90 in the front. Doing some research, looks like Ford switched over in 2015 to the 75w-85 for the rear, but kept the 80w-90 for the front. Then in 2016, they switched the front requirement over to match the rear at 75w-85. Did they realize that 75w-140 / 80w-90 is complete overkill for their intended purpose, or does it have to do more with MPG's ? It's just puzzling since Ford years ago made a huge stink about HAVING to use 75w-140 in their rear diff's, even going so far as to back date older vehicles that originally said to use 80w-90 to the 75w-140 requirement.....
F150 Diff Fluid
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That's odd but I imagine they discovered a design flaw and are discovered it can be fixed with that new oil?
It is kinda weird, but do it if you want to keep your warranty.
It is kinda weird, but do it if you want to keep your warranty.
Originally Posted By: zeng
It's about mpg and CAFE.Period.
....and is called 'optimum' vehicle performance, NOT maximum wear protection.
+1
Any way to squeeze out 1 more mpg and put them a step ahead.
It's about mpg and CAFE.Period.
....and is called 'optimum' vehicle performance, NOT maximum wear protection.
+1
Any way to squeeze out 1 more mpg and put them a step ahead.
Originally Posted By: meep
I would think a properly designed diff in a half-ton wouldn't need anything over 90 weight. I wonder why it was 140 to begin with?
Ford had an issue years ago with what customers perceived as "excessive" gear whine from the rear end. There was nothing wrong at all, their ring & pinions would sometimes have a little gear whine on the coast side (or off throttle) side of the rear ring & pinion. People perceived this as "somethings wrong" & Ford's fix was to use 75w-140 gear oil to dampen the noise. They stuck with the 75w-140 all the way up to 2014, then changed it to 75w-85 in 2015 & newer trucks. So I'm wondering if they changed Ring & Pinion suppliers when they switched to the aluminum bodies to a different type of metal that produces less noise during gear contact, & therefore switched to the lighter oil because the 75w-140 wasn't needed to control gear whine anymore.....just a thought.
I would think a properly designed diff in a half-ton wouldn't need anything over 90 weight. I wonder why it was 140 to begin with?
Ford had an issue years ago with what customers perceived as "excessive" gear whine from the rear end. There was nothing wrong at all, their ring & pinions would sometimes have a little gear whine on the coast side (or off throttle) side of the rear ring & pinion. People perceived this as "somethings wrong" & Ford's fix was to use 75w-140 gear oil to dampen the noise. They stuck with the 75w-140 all the way up to 2014, then changed it to 75w-85 in 2015 & newer trucks. So I'm wondering if they changed Ring & Pinion suppliers when they switched to the aluminum bodies to a different type of metal that produces less noise during gear contact, & therefore switched to the lighter oil because the 75w-140 wasn't needed to control gear whine anymore.....just a thought.
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There's a pretty big difference between good and bad gear whine, IMO. My old STI, with a helical/torsen front/rear would sound awesome upon deceleration, especially in a parking garage, coasting slowly down a ramp in 1st or 2nd gear. I can see most people not liking that kind of thing.
The 140 part of their 75W140 grade is just a baby step above 110 grade. Unless you are driving in weather colder than -25F, 80W140 synthetic is truly a thicker oil than xW90 and most xW110s.
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OEM OCD - Or in Ford's case OEM ADHD
Interesting, my 2016 manual for the 3.5EB says:
- Front axle fluid (U.S.): Motorcraft SAE 80W-90 Premium Rear Axle Lubricant XY-80W90-QL
- Rear axle fluid: Motorcraft SAE 75W-85 Premium Synthetic Hypoid Gear Lubricant XY-75W85-QL
I like how the oil for the front axle says "rear axle".
- Front axle fluid (U.S.): Motorcraft SAE 80W-90 Premium Rear Axle Lubricant XY-80W90-QL
- Rear axle fluid: Motorcraft SAE 75W-85 Premium Synthetic Hypoid Gear Lubricant XY-75W85-QL
I like how the oil for the front axle says "rear axle".
Originally Posted By: Onug
Interesting, my 2016 manual for the 3.5EB says:
- Front axle fluid (U.S.): Motorcraft SAE 80W-90 Premium Rear Axle Lubricant XY-80W90-QL
- Rear axle fluid: Motorcraft SAE 75W-85 Premium Synthetic Hypoid Gear Lubricant XY-75W85-QL
I like how the oil for the front axle says "rear axle".
Yes, Ford switched over the rear diff fluid to 75w-85 in 2015, but kept 80w-90 for the front until 2017 where they use 75w-85 for both the front & rear diffs now. It's kinda weird if you ask me, or they just had a supply of 80w-90 they had to use up before switching both front & rear diffs to the same gear oil.
Interesting, my 2016 manual for the 3.5EB says:
- Front axle fluid (U.S.): Motorcraft SAE 80W-90 Premium Rear Axle Lubricant XY-80W90-QL
- Rear axle fluid: Motorcraft SAE 75W-85 Premium Synthetic Hypoid Gear Lubricant XY-75W85-QL
I like how the oil for the front axle says "rear axle".
Yes, Ford switched over the rear diff fluid to 75w-85 in 2015, but kept 80w-90 for the front until 2017 where they use 75w-85 for both the front & rear diffs now. It's kinda weird if you ask me, or they just had a supply of 80w-90 they had to use up before switching both front & rear diffs to the same gear oil.
Same with the GM/Chev LTs Zeng.
The auto manufactures stand between the component manufactures and their dealerships.
The dealerships stand between the customers and the auto manufactures.
If we skip all the middle men 'n women and government mandates like CAFE and go directly to the component manufactures' web sites,
we typically end up with two choices, 75w90 and 80w140.
The auto manufactures stand between the component manufactures and their dealerships.
The dealerships stand between the customers and the auto manufactures.
If we skip all the middle men 'n women and government mandates like CAFE and go directly to the component manufactures' web sites,
we typically end up with two choices, 75w90 and 80w140.
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Thanks Userfriendly, for the clarification on rear axle being all-time drive.
Originally Posted By: Fasttimez
Ford switched over in 2015 to the 75w-85 for the rear, but kept the 80w-90 for the front.
This switch of Ford defies laws of physics ......or principles of tribology......
as all-time rear differrential requires similar , if not higher viscosity grade (80W90 or higher ) than a part-time front differential (at 80W90) which generally is lighter duty and works cooler ...... in a typical 4WD...... basing on the laws of physics.
Having said this, I can understand Ford's thought processes in switching oil grades from 75W140 to 75W85, capitalising terms in CAFE probably(IDK) .... with an ultimate aim of gaining credits to improve company financial standings.
I may be flamed for suggesting oil recommendations by automakers/auto-assemblers for markets in States are generally 'distorted' by marketing/finance departments ..... in the context of CAFE......
and engineering department is made to take a back seat....... playing periphery roles.........
which fortunately or unfortunately, is a general trend in this world called Capitalism.
Originally Posted By: userfriendly
....component manufactures' .....we typically end up with two choices, 75w90 and 80w140.
I would speculate in this scenario:
marketing department recommends 75W90, and
engineering department requires 80W140.
Originally Posted By: Fasttimez
Ford switched over in 2015 to the 75w-85 for the rear, but kept the 80w-90 for the front.
This switch of Ford defies laws of physics ......or principles of tribology......
as all-time rear differrential requires similar , if not higher viscosity grade (80W90 or higher ) than a part-time front differential (at 80W90) which generally is lighter duty and works cooler ...... in a typical 4WD...... basing on the laws of physics.
Having said this, I can understand Ford's thought processes in switching oil grades from 75W140 to 75W85, capitalising terms in CAFE probably(IDK) .... with an ultimate aim of gaining credits to improve company financial standings.
I may be flamed for suggesting oil recommendations by automakers/auto-assemblers for markets in States are generally 'distorted' by marketing/finance departments ..... in the context of CAFE......
and engineering department is made to take a back seat....... playing periphery roles.........
which fortunately or unfortunately, is a general trend in this world called Capitalism.
Originally Posted By: userfriendly
....component manufactures' .....we typically end up with two choices, 75w90 and 80w140.
I would speculate in this scenario:
marketing department recommends 75W90, and
engineering department requires 80W140.
Why not just split the difference & use 75w-110 ? It seems to be a "happy medium" between 75-w90 & 75w-140. I've read many reports stating 75w-140 is overkill in a 1500 series truck. Ford for some reason was one of the only companies to switch to the 75w-140, while most everyone else stuck with either 75w-90 or 80w-90. Funny how it's come back full circle to Ford now requiring 75w-85 instead of the 75w-140. Studying the Widman Viscosity Chart, a 110 gear oil is more than efficient for our operating conditions (If I'm studying the chart correctly). It looks like a 140 gear oil is very overkill for our applications.
Originally Posted By: BISCUT
Can anyone explain why 75W85 and not just use the 75W90?
75W-85 ensures you are using a full synthetic and not a conventional or semi-synthetic that can be found in 75W-90 gear oils.
That being said, 99.9% of people can get by just using a good full synthetic 75W-90 gear oil as finding 75W-85 can be a bit of a pain finding in brick and mortar establishments and/or sticker shock when found.
FWIW, I am running Castrol 75W-90 in my 2016 F150 with no issues or concerns.
Can anyone explain why 75W85 and not just use the 75W90?
75W-85 ensures you are using a full synthetic and not a conventional or semi-synthetic that can be found in 75W-90 gear oils.
That being said, 99.9% of people can get by just using a good full synthetic 75W-90 gear oil as finding 75W-85 can be a bit of a pain finding in brick and mortar establishments and/or sticker shock when found.
FWIW, I am running Castrol 75W-90 in my 2016 F150 with no issues or concerns.
I am changing my rear differential cover to a Mag-Hytec. Should be here next week. I also noticed the 75w85 factory spec. I am going to use 5+ quarts of Delo Syn-Gear XDM 75w90 when I change the cover. Autozone has this for $5.99 a quart. Great price for a full synthetic gear lube.
Good price, cheaper at the bulk dealer if you needed 5 gallons. Pds shows 75W90 and 80W140 passing J2360 and carries Dana's 750,000 mile warranty.
I would put the 80W140 grade in the light 140s and just breaks into the 140 grade, 85W140s tend to be thicker at 100C.
www.chevronlubricants.com
I would put the 80W140 grade in the light 140s and just breaks into the 140 grade, 85W140s tend to be thicker at 100C.
www.chevronlubricants.com
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