How To Weak Vacuum Line and grinding noise FIX

[SRoth]

I've got a 2015 with 98k....just started the grinding at speeds greater than 75-80 and usually under acceleration. I've swapped the solenoid and have checked vacuum. I'm only getting the noise intermittently now...but still grinding. Any ideas on why it might be intermittent?

 

[Wilson]

^ power makes it slip over the week gears in the IWE. you'll have to replace them also.

 

[Sailboater410]

My 2018 F-150 now has 6k miles, started getting intermittent scraping noises at about 5k, which is pretty darned early in life IMHO. I'm off to buy a vacuum gauge and start troubleshooting. The dealer I purchased from is willing to take a look, but when I asked how he'd troubleshoot such an intermittent problem he didn't know. I suggested I'll try the shift-into-4WD-mode test to see if the noise stops and at least give him some info that is more valuable. (I didn't know about that test until this morning so haven't had the noise to try the test yet.)

Anyway, I guess my point here is that the symptoms can occur on an almost new truck.


Cheers.

 

[Sailboater410]

Mil T -
I've read the entire thread and I have a question which, with your disassembly/re-assembly background, you might be able to answer. The sounds are described as either grinding, or clicking, or like cards on bicycle spokes. The noise I hear in my 2018 is grinding as if a brake rotor was rubbing on a piece of stuck gravel. If a partial hub engagement is occurring, why would it sound like grinding? I can understand why it would sound like clicking or cards-on-spokes due to gear teeth partially meshing, but why grinding? Is there an intermediate synchro ring in there somewhere that I don't see?

Thanks, just trying to understand a little more.
Ron

 

[tales_from_the_crimp]

Did anyone save the photos that were in the OP? I have this issue and would love to go a hardlined route over the stock rubber which will wear out over time

 

[Xcommie]

Anyway I can get the photos again... I can't see them now and I have the same issue after my last escapade...

 

[Wilson]

basically you just follow the old lines and replace them with this setup. I still have not done this. all I have is a hammer, plier and a hand full of wrenches. and I'm lazy

 

[Wilson]

another idea is to print the page and read it while looking at your truck. should be pretty obvious.

 

[Scott McLeod]

I had this issue on my 2016 F150 FX4 Lariat. It took several trips to the dealer before someone figured it out. Since I had a small vacuum leak it happened very intermittently, particularly when the engine was turning low RPM and boost was lower - so effectively not quite enough vacuum to keep 4x4 disengaged. The dealer could never replicate the issue while test driving from the shop. So they had me verify by putting the system in 4A next time I heard the noise - Yahtzee! They then found the leak in a fitting near master cylinder and all was good.

 

[TXRaptor]

Then oblige us all and go do it and take new pics for us or quit ******** up a useful thread by offering ZERO technical content.

Wow, pretty critical of someone who was just trying to help out. Maybe you should take your own advice...