2005 f350 hubs will not lock in auto.changed pulse solenoid checked vacumn on all lines and hubs could hear relays clicking and hubs hold vacumn but still will not lock any help will be appreciated. Thanks for your reply.

 

Is there a position for auto lock or manual lock on the hubs themselves?

 

I guess the next step is to disassemble and clean the hubs.

 

There used to be a Ford Dealership called Rusty Shakalford near here.

 

I'm betting on bad hub o-rings. When they get dry over time they leak vacuum.

 

I'm haveing the same problem out of my 04, checked and rechecked everything that I know of but still can't get it to lock in.

 

Are you getting the vacuum pulse at each wheel?

 

What will cause the relays not to work? I have power at the connectors but the relays will not click. Ive checked the relays with a ohm meter and they check out okay. All vacuum lines are good, hubs are good PVH solenoid works, vacuum pump works transfer case is working, all fuses are good. What's next?

 

Replace the relay, about the only thing. When applying vacuum to each hub, does it lock in?

 

Mine will not lock even tho it holds good vacumn with a vacumn pump

 

Jack the wheel up and apply vacuum to that hub while spinning the tire. If it holds good vacuum and still won't lock when spinning it, clean the hub.

Book says you need to be going about 5 mph when using the auto feature.

Mine did the same thing... replaced everything on that side and still wouldn't lock. I cleaned the hub, locked and unlocked a few times while jacked up and spinning the tire, works now. Just figured that since the auto feature wasn't working, it was kind of frozen up, mine hadn't been in 4 high from the previous owner. Said it never went off the road or even in gravel.

Both sides needed cleaning and now I run it in 4 high as often as I can to keep it freed up.

 

From the owners manual:

The electronic shift 4WD system is designed to allow up to 45
seconds before a shift command is performed. In the event that
conflicting shift commands are selected, allow up to 45 seconds
for the shift command to be performed prior to reporting any
shift concerns to your dealer.

-----------------------------

Shifting from 2WD (2WD High) to 4x4 HIGH (4WD High)
Rotate the 4WD control to the 4x4
HIGH position at speeds up to 55
mph (88 km/h).
• The electronic shift 4WD
system is designed to engage
4x4 HIGH (4WD High) when
the vehicle is moving. If
shifted to 4x4 HIGH (4WD
HIGH) while at complete stop,
4x4 may not engage and the
4x4 indicator may not
illuminate until the vehicle is driven above 5 mph (8 km/h).

 

I need to shift into 4x4 before the race starts and we come to a complete stop... then I'm locked and loaded

 

As mentioned above, try to lock them while spinning the tire in the air. If you are getting vacuum to the hubs and they are holding vacuum and still won't lock even with the tire spinning then they need to be pulled off and serviced. Here is a video on how to do it.


Good Luck,

Baatzy