Hubs

bearguy · 12-10-2008, 08:28 AM

i have a 2002 f350. if i lock the hubs in maually 4wheel drive works. turn the switch for the auotmatic and i hear it engage but no 4 wheel drive. can someone help

75K30 · 12-10-2008, 09:21 AM

You have a very common problem with the ESOF system. This "electronic shift on the fly" system is very problematic. These problems are often vacuum related. The hubs work on a pulsed vacuum system and should not be confused with steady manifold vacuum. You have either a leak in one or more lines. You have a leak at the seal in the hub assembly, or a bad vacuum module located under the hood.
Since the transfer case appears to work the actuator is functional, and it leads me to believe that you have a leak somewhere.
The lines at the hub tend to leak.

tjzz4 · 12-10-2008, 09:58 AM

+1 Like 75 said.

mrjohnwayne · 12-10-2008, 10:22 AM

Ditto, vacuum leak.

12-10-2008, 08:28 AM	#1
bearguy Junior Member Join Date: Dec 2008 Posts: 2	Hubs i have a 2002 f350. if i lock the hubs in maually 4wheel drive works. turn the switch for the auotmatic and i hear it engage but no 4 wheel drive. can someone help

12-10-2008, 10:22 AM	#4
mrjohnwayne Senior Moderator Join Date: Apr 2005 Location: Texas Posts: 3,722	Ditto, vacuum leak. __________________ John Wayne 2000 F-350 7.3L Powerstroke 4x4

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Replacing hubs	vinniepro	Ford Truck Forum	9	11-19-2008 06:50 PM
I need a set of DRW front 4x4 hubs ASAP!!!!!!!!!!	Lonesome7.3	Truck Classifieds	7	08-01-2008 04:11 AM
4wd hubs won't engage	riata_ag	Chevy Truck Forum	16	03-29-2007 09:16 PM
Front Hubs on 2WD Jimmy S15	jktuck	GMC Truck Forum	0	12-22-2006 02:37 PM
auto hubs	colocat	Ford Truck Forum	2	05-01-2006 05:47 PM

12-10-2008, 09:21 AM	#2
75K30 Senior Member Join Date: Jul 2006 Posts: 2,992	You have a very common problem with the ESOF system. This "electronic shift on the fly" system is very problematic. These problems are often vacuum related. The hubs work on a pulsed vacuum system and should not be confused with steady manifold vacuum. You have either a leak in one or more lines. You have a leak at the seal in the hub assembly, or a bad vacuum module located under the hood. Since the transfer case appears to work the actuator is functional, and it leads me to believe that you have a leak somewhere. The lines at the hub tend to leak.

12-10-2008, 09:58 AM	#3
tjzz4 Senior Member Join Date: Oct 2007 Posts: 277	+1 Like 75 said.