arokcrwlr

I completed the mod that I initially termed the "2Lo Mod", but a better description would be the "Front Hub Disconnect Mod".

It allows 2Lo by disconnecting the front hubs while in 4Lo. Another benefit, if you have an e-locker, is the ability disengage the front hubs and effectively have the e-locker in 2wd to the speed limitation of the 4wd mode selected.

Why?

There are many benefits:

1. Useful in backing up a heavy trailer up an incline - easier on the transmission, etc.
2. It's great for maneuvering into tight places, especially if you need to turn the front wheels full lock - no driveline bind.
3. Any other scenario where you'd want low range on a high traction surface where 4wd would cause driveline binding.

Here's how it's done...

Refer to the ESOF schematic provided by dlh4x4 in the E-locker override thread. The wire from the solenoid to the TCCM needs to be switched to ground when 4wd is engaged to supply vacuum to the IWE which keeps the hubs disengaged.



Locate the IWE solenoid on the driver's side in the engine bay - it's next to the vacuum booster.



Per the schematic, constant power is provided by the GY-RD wire and the BN-BU connects to the TCCM and is the wire that needs to be cut.



I used a 30 amp relay to do the switching to help with trouble shooting and make it easier to correct a faulty switch in the cab. I mounted the relay to one of the vacuum booster mounting bolts and used a relay pigtail for the connections.



Then it's just a matter of making the appropriate relay connections and wiring the switch in the cab - all wire splices were soldered and covered with shrink tubing. Pin 30 connects to BN/BU wire coming from solenoid. Pin 87a connects to BN/BU wire going to TCCM. Pin 86 and 87 go to ground. Pin 85 comes from a switch that has 12v.

With the switch off, the system works like it should. Switch on, grounds the solenoid completing the circuit and keeps vacuum going to the IWEs. With the transfercase in 4x4 with the switch on will keep the wheel hubs unlocked.

All relay ground connections were routed to a ground point on the left side of the engine bay.



Connections cleaned up and routed...



Switch connection poked through the main wiring grommet on firewall...



Power for switch from a fuse piggy back harness...



I tested it at various speeds with/without the e-locker and it works perfectly. I need to re-do my switch - I originally mounted it in the little dash panel below the Sync badge on the dash, but with the area wasn't deep enough for the switch connections with the panel in place. I need to replace the little panel and find a different location.

If anyone decides to do this mod, I hope you find this useful.

blackknight87

Cool. Me personally i wouldnt need it. But like you said i bet it would come in handy for some ppl!

pfbz

Nice work...

Could not a similar modification be used to manually engage the e-lock diff, regardless of ESOF switch position and not requiring the Raptor ECCM swap?

Perhaps like this:


Override switch on: diff is locked regardless of ESOF setting or speed. 2WH lock, 4WH lock, 4WL lock, any speed.
Override switch off: diff lock works as Ford intended.


Seems easy enough to force the diff to lock. Wonder if it would throw any transmission error codes.

arokcrwlr

Theoretically, I think that would work, but I don't know if it will throw codes or cause any other undesirable effects. I think you should try it and report back.

BassAckwards

So when you flip this switch does that automatically engage 4wd? or does that just keep the hubs from engaging and you still need to turn the 4wd ****?

arokcrwlr

It just keeps the hubs from engaging - to get 2low and e-locker (without Raptor parts) you still have to turn the 4wd ****.

spdmpo

So we have hubs that engage and disengage, and not unit bearings?

arokcrwlr

If you have 4x4 ESOF, then yes, the hubs (or in Ford speak, Integrated Wheel Ends/IWE's) engage and disengage. The front hubs are actuated by lack of vacuum. Vacuum is supplied when the IWE solenoid is energized (i.e. when 2wd is selected). When 4wd is selected, the TCCM opens the solenoid's ground path - thus removing vacuum and the IWE spring allows the hubs to engage.

There are only 2 wires going to the IWE solenoid - one is constant hot and the other goes to the TCCM. By simply switching the TCCM wire to ground (thereby completing the circuit) you can disengage the front hubs while in 4wd. If in 4Lo, you effectively have 2lo. In either 4wd mode, this mod will also give you the 2wd e-locker (if equipped) up to the speed limitation of the selected 4wd mode.

Am I making sense, or causing confusion???

spdmpo

You make sense. I was confused on what you call hubs. I am familiar with ESOF and came out of a 2000 superduty with it. But the locking hubs could also be locked manually. Obviously these are a much different design than conventional hubs.

dmz01

So with this mod can I leave the truck in 4hi all the time and only control the front and rear with this new switch and the e-lock switch respectively?