4 wheel drive help
Thread Starter
|
Cross-Country
Joined: Sep 2010
Posts: 80
Likes: 0
4 wheel drive help
i have a 2004 f-250 6.0 kr 4x4. we have recently and again tonight had snow in east texas and my 4 wheel drive doesn't work. i have read all the threads and looked through the spreadsheets on here and got some good help, but here's what is happening. i can put the switch in 4x4 high and check vaccum to each side at the hub. i have great vaccum for a second then it dies. i have isolated each side and checked them by their self and i show no leaks. i have not checked it with a gauge. but i do have great vaccum to each side individually with my thumb over the line. could the vaccum switch be going bad? the pump comes on and runs about 2 minutes before it shuts off. with everything hooked up right and in 4x4 high i can still turn the front axle. thanks.
< Samantha...my Co-Pilot
Joined: Dec 2001
Posts: 768
Likes: 11
From: Fallon, Nevada
I don't think that continuous vacumm is supplied to the hubs...only a pulse that causes them to engage and disengage. I might be wrong (would not be the first time) but I remember reading that here on the forums somewhere. Possibly the hubs are just "gummed up" or there are leaks at the hubs themselves. Twist in the hubs manually and drive them around for a while...then twist them out to "auto" and see if the ESOF will work then. Do a search or check the tech folder...or maybe someone else who knows for sure will post.
Senior User
Joined: Dec 2010
Posts: 177
Likes: 1
From: Wasilla, Alaska
Lead Driver
Joined: Sep 2005
Posts: 9,399
Likes: 188
From: Norco,CA
I have been wondering that and keep meaning to check it out on mine. My hubs like to come unlocked when most needed so I just leave them manually locked in instead of relying on the ESOF. Need to figure it out and fix it at some point but keep getting side tracked with other issues like head gaskets, seat heater, etc.
Senior User
Joined: Dec 2008
Posts: 144
Likes: 1
From: Deerfield, VA
As the previous poster said, the vacuum pulses, 45 seconds to engage, I think 20 seconds to disengage. Your easiest recourse is to manually lock the hubs in by turning them clockwise until they stop, counterclockwise when 4WD is no longer needed. 4wd will still engage and disengage with the switch. My hubs work great, my truck is just crotchety engaging 4X4 while moving.
John
John
Thread
Thread Starter
Forum
Replies
Last Post
wildwheelerb200
1999 - 2016 Super Duty
6
Apr 4, 2010 12:08 PM
