ESOF auto 4wd not engaging

jcain · Dec 6, 2015

A turn of the dash knob and 4x4hi lights up, hear and feel the xfer case engage but still 2wd.

Manually lock hubs and it's fine.

Replaced both sensors on the backside of the wiper fluid tank.

Replaced full vacuum harness from wiper fluid tank to hubs.

All hvac controls work fine.

Can hear a chirping sound when trying esof 4hi while driving down the street from right wheel side.

Truck has just over 70,000 miles

What's my next step, hub seals?

Is there a better aftermarket auto hub to replace them with while I'm at it?

Thanks for any help.

Jomax · Dec 7, 2015

Did you make sure none of the vacuum hoses aren't cut, popped out or broken?

Sent from my iPhone using Tapatalk

jcain · Dec 7, 2015

I mentioned I replaced the whole vacuum harness.

pdumont01 · Dec 7, 2015

Vacuum seals that are on the front shafts go bad, especially if the axles were removed and installed and the seals were not replaced. Same goes for the o-ring around the wheel bearing. Take a vacuum pump and pump up each side separately at the knuckle nipple, a leak will be evident.

Sent from my Nexus 6 using Tapatalk

huntnfishnfreak · Dec 9, 2015

My 2014 started doing this as well at about 15k..still like this at 31k. Stealership says that's just the way it is lol...I give up. They never were able to fix my 2004 that did the same thing. So I guess I'll have to run with the the hubs manually locked all winter just like the good old days... I so wish I access to a stealership with a mechanic that actually wanted to fix things.....

Sent from my XT1254 using Tapatalk

Jomax · Dec 9, 2015

huntnfishnfreak said:
My 2014 started doing this as well at about 15k..still like this at 31k. Stealership says that's just the way it is lol...I give up. They never were able to fix my 2004 that did the same thing. So I guess I'll have to run with the the hubs manually locked all winter just like the good old days... I so wish I access to a stealership with a mechanic that actually wanted to fix things.....

Sent from my XT1254 using Tapatalk

Go to a different dealership that's a bunch of horse crap.

Sent from my iPhone using Tapatalk

huntnfishnfreak · Dec 9, 2015

Jomax said:
Go to a different dealership that's a bunch of horse crap.

Sent from my iPhone using Tapatalk

I actually fixed my 04 by putting in a new vacuum pump after the stealership replaced just about every moving part associated with the four wheel drive except the vacuum pump. I have to pretty much diagnose any problem and the fix before it'll be fixed. The mechanic has pushed me so far over my limits that I refuse to bring my new truck in there especially after I called about this problem and got this answer...the nearest dealer besides them is probably 150mi away unfortunately so I've needed to learn, follow forums etc and fix my own stuff regardless of warranty, which sucks...but at least I'll have my truck.

Sent from my XT1254 using Tapatalk

morefuel · Dec 9, 2015

Have you tried a new vaccum switch or whatever that soleniod that switches the vacuum is called? Pretty sure thats whats wrong with mine. Has vacuum up to it and if i apply vaccum directly to the hubs or bypass it they lock in great.