2015 F150 front and rear diff fluid

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Originally Posted by hatt
Originally Posted by meep
I'd run syn in the front as well - ideally for thinner cold weather characteristics. It's a waste to spin all that stuff when just needing RWD. I *really* wish there was a manual hub offering for these things so we could disconnect the front driveline unless we actually need it. It gained me 1 mpg in past on a pathfinder.
These trucks(or most of them) disengage the front driveline when in 2wd via vacuum operated hubs.
+1 - they are disengaged unless 4WD is active.
 
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the newer ones have no disconnect for the front axle. Spins full time. I have an '18 XL STX 4x4. They went away from the vacuum hubs sometime around 15 I think? There is a pretty big difference in MPG between the 2wd and 4wd. It seems they could have really helped their cafe numbers if they'd kept the vac system in there, even if it wasn't known for being that robust.
 
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Originally Posted by meep
the newer ones have no disconnect for the front axle. Spins full time. I have an '18 XL STX 4x4. They went away from the vacuum hubs sometime around 15 I think? There is a pretty big difference in MPG between the 2wd and 4wd. It seems they could have really helped their cafe numbers if they'd kept the vac system in there, even if it wasn't known for being that robust.
Are the newer trucks all AWD? My 13 has an old school transfer case pretty much the same as stuff from the 80s.
 
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Originally Posted by meep
the newer ones have no disconnect for the front axle. Spins full time. I have an '18 XL STX 4x4. They went away from the vacuum hubs sometime around 15 I think? There is a pretty big difference in MPG between the 2wd and 4wd. It seems they could have really helped their cafe numbers if they'd kept the vac system in there, even if it wasn't known for being that robust.
If that is the case, I wonder why Ford does not spec. the thinner lube for the front differential also?
 
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Thread starter
Originally Posted by Rob_Roy
Originally Posted by meep
the newer ones have no disconnect for the front axle. Spins full time. I have an '18 XL STX 4x4. They went away from the vacuum hubs sometime around 15 I think? There is a pretty big difference in MPG between the 2wd and 4wd. It seems they could have really helped their cafe numbers if they'd kept the vac system in there, even if it wasn't known for being that robust.
If that is the case, I wonder why Ford does not spec. the thinner lube for the front differential also?
They do, it occurred sometime after my 2015.
 
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Originally Posted by meep
the newer ones have no disconnect for the front axle.
I wonder what the reasoning was for this? Transfer case oil pump on front input shaft? LOL Are the vacuum hubs anything less than instant/seamless in operation, such that the delay of engaging/disengaging was considered unacceptable?
 
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Originally Posted by Buzzinhalfdozen
Originally Posted by Rob_Roy
Originally Posted by meep
the newer ones have no disconnect for the front axle. Spins full time. I have an '18 XL STX 4x4. They went away from the vacuum hubs sometime around 15 I think? There is a pretty big difference in MPG between the 2wd and 4wd. It seems they could have really helped their cafe numbers if they'd kept the vac system in there, even if it wasn't known for being that robust.
If that is the case, I wonder why Ford does not spec. the thinner lube for the front differential also?
They do, it occurred sometime after my 2015.
Right you are - I just pulled out the manual for my 2016 and it calls for 75w-85 in the front.
 
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Originally Posted by meep
the newer ones have no disconnect for the front axle. Spins full time. I have an '18 XL STX 4x4. They went away from the vacuum hubs sometime around 15 I think? There is a pretty big difference in MPG between the 2wd and 4wd. It seems they could have really helped their cafe numbers if they'd kept the vac system in there, even if it wasn't known for being that robust.
I just saw a forum post of someone with 2017 hub issues. Actuator for 2018. https://www.mclaughlinmotorsparts.c...tial-Lock-Motor/75136169/HL1Z3C247A.html
 
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^^^ dumbfounded? I had the wheels off 2 weeks ago to rotate the tires. the axles spun with the hubs. Not sure what to make of that website, showing the vac hub for a 2018? ^^^
 
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Originally Posted by meep
^^^ dumbfounded? I had the wheels off 2 weeks ago to rotate the tires. the axles spun with the hubs. Not sure what to make of that website, showing the vac hub for a 2018? ^^^
Did you rotate the tires with the engine running? smile Unless the engine is running, there's no vacuum to release the hubs. Engine off, no vacuum... everything will spin.
 
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Thread starter
Originally Posted by dustyroads
Originally Posted by meep
^^^ dumbfounded? I had the wheels off 2 weeks ago to rotate the tires. the axles spun with the hubs. Not sure what to make of that website, showing the vac hub for a 2018? ^^^
Did you rotate the tires with the engine running? smile Unless the engine is running, there's no vacuum to release the hubs. Engine off, no vacuum... everything will spin.
I believe the 2014 and previous gen would be in 2wd and the vacuum hub would then engage to 4wd. The 2015+ I believe is in 4wd and then the vacuum system engages 2wd.
 
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Originally Posted by dustyroads
Originally Posted by meep
^^^ dumbfounded? I had the wheels off 2 weeks ago to rotate the tires. the axles spun with the hubs. Not sure what to make of that website, showing the vac hub for a 2018? ^^^
Did you rotate the tires with the engine running? smile Unless the engine is running, there's no vacuum to release the hubs. Engine off, no vacuum... everything will spin.
Dude. Question of the day. Awesome. "ah, no - that would be I did not." I'm gonna climb under this thing and look for vacuum hoses next chance I get. I'll be tickled if it has them.
 
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upstate NY
Originally Posted by Buzzinhalfdozen
Originally Posted by dustyroads
Originally Posted by meep
^^^ dumbfounded? I had the wheels off 2 weeks ago to rotate the tires. the axles spun with the hubs. Not sure what to make of that website, showing the vac hub for a 2018? ^^^
Did you rotate the tires with the engine running? smile Unless the engine is running, there's no vacuum to release the hubs. Engine off, no vacuum... everything will spin.
I believe the 2014 and previous gen would be in 2wd and the vacuum hub would then engage to 4wd. The 2015+ I believe is in 4wd and then the vacuum system engages 2wd.
I believe those two sentences are saying the same thing, just different ways (even if you don't mean to). I truly don't know what changed with the '15 and newer F150s other than the aluminum body. But I would think that my '13, your '15 and meep's '18 use the same system. Maybe there's something different for the high-end models with 4A position on the selector, but I'd bet a cup of coffee that those of us without 4A have the same vacuum operated hubs. That is; engine off, hubs are locked (engaged), and starting the engine supplies vacuum and unlocks the hubs (until you turn the selector to 4X4). I've not had any trouble with my '13 yet and really not informed other than the most basic operation of the system, but it seems quite easy and inexpensive to fix at home. I'm here to learn so please correct me if I'm wrong about anything. thumbsup
 
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Originally Posted by meep
Originally Posted by dustyroads
Originally Posted by meep
^^^ dumbfounded? I had the wheels off 2 weeks ago to rotate the tires. the axles spun with the hubs. Not sure what to make of that website, showing the vac hub for a 2018? ^^^
Did you rotate the tires with the engine running? smile Unless the engine is running, there's no vacuum to release the hubs. Engine off, no vacuum... everything will spin.
Dude. Question of the day. Awesome. "ah, no - that would be I did not." I'm gonna climb under this thing and look for vacuum hoses next chance I get. I'll be tickled if it has them.
LOL! I knew the answer, just being a wise guy. Unless Ford came up with a whole new system, I'd expect your '18 to be like mine. Let us know if anything is different.
 
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The independent wheel ends (IWE), which are analogous to the old locking hub assemblies, have been vacuum actuated for some time now. Vacuum disengages the iwe putting it into 2wd this when vacuum is released the iwe re-engages for 4wd. I believe it has been this way since before 2011. I may be wrong on that, though.
 
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Houston, TX
Originally Posted by meep
^^^ dumbfounded? I had the wheels off 2 weeks ago to rotate the tires. the axles spun with the hubs. Not sure what to make of that website, showing the vac hub for a 2018? ^^^
It is a Ford dealer's parts catalog. I agree with the others, highly doubtful that Ford came out with a new design and even more doubtful since they obviously show the vacuum system in the parts catalog. BDCardinal could answer this with absolute certainty; he works at a Ford dealership in the parts department.
 
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Thread starter
Originally Posted by dustyroads
Originally Posted by Buzzinhalfdozen
Originally Posted by dustyroads
Originally Posted by meep
^^^ dumbfounded? I had the wheels off 2 weeks ago to rotate the tires. the axles spun with the hubs. Not sure what to make of that website, showing the vac hub for a 2018? ^^^
Did you rotate the tires with the engine running? smile Unless the engine is running, there's no vacuum to release the hubs. Engine off, no vacuum... everything will spin.
I believe the 2014 and previous gen would be in 2wd and the vacuum hub would then engage to 4wd. The 2015+ I believe is in 4wd and then the vacuum system engages 2wd.
I believe those two sentences are saying the same thing, just different ways (even if you don't mean to). I truly don't know what changed with the '15 and newer F150s other than the aluminum body. But I would think that my '13, your '15 and meep's '18 use the same system. Maybe there's something different for the high-end models with 4A position on the selector, but I'd bet a cup of coffee that those of us without 4A have the same vacuum operated hubs. That is; engine off, hubs are locked (engaged), and starting the engine supplies vacuum and unlocks the hubs (until you turn the selector to 4X4). I've not had any trouble with my '13 yet and really not informed other than the most basic operation of the system, but it seems quite easy and inexpensive to fix at home. I'm here to learn so please correct me if I'm wrong about anything. thumbsup
I think your right. From looking at it more now I think I confused IWE operation with the super duty CVH. It appears IWE design hasn't changed from what I found. Sorry for any confusion. 🍻
 
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Originally Posted by dustyroads
Originally Posted by meep
Originally Posted by dustyroads
Originally Posted by meep
^^^ dumbfounded? I had the wheels off 2 weeks ago to rotate the tires. the axles spun with the hubs. Not sure what to make of that website, showing the vac hub for a 2018? ^^^
Did you rotate the tires with the engine running? smile Unless the engine is running, there's no vacuum to release the hubs. Engine off, no vacuum... everything will spin.
Dude. Question of the day. Awesome. "ah, no - that would be I did not." I'm gonna climb under this thing and look for vacuum hoses next chance I get. I'll be tickled if it has them.
LOL! I knew the answer, just being a wise guy. Unless Ford came up with a whole new system, I'd expect your '18 to be like mine. Let us know if anything is different.
I love it. I was working on it last night but forgot to peek under there and see for myself!
 
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Originally Posted by 2015_PSD
Originally Posted by meep
^^^ dumbfounded? I had the wheels off 2 weeks ago to rotate the tires. the axles spun with the hubs. Not sure what to make of that website, showing the vac hub for a 2018? ^^^
It is a Ford dealer's parts catalog. I agree with the others, highly doubtful that Ford came out with a new design and even more doubtful since they obviously show the vacuum system in the parts catalog. BDCardinal could answer this with absolute certainty; he works at a Ford dealership in the parts department.
Y'ALL are indeed right! There are vacuum lines running into the wheel hubs. Thanks for the info! -m
 
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