Has anyone changed their A4WD to a 4WD/2WD set up? The reason for the question is my ‘98 Expedition has 4WD/2WD and my ‘00 Navigator has A4WD. The Expi. Has the 4R70 trans and the Navigator has the 4R100. I’m not certain if the transfer cases are the same but I doubt it. My navigator has no problem with the transfercase and drives great. I would just like the option of choosing the system I use while driving. If I would have to change the t/case and do a bunch of rewiring it will stay as it is but if it’s not a big deal I would like to make the changes needed.

 

Dont take this the wrong way but are you sure its AWD and not A4WD? Because theres a huge difference. AWD is on all the time, A4WD kicks on 4WD as needed if you start slippin' and whatnot. BTW if you pull the T-Case actuator motor off youll see the little "dial" that the motor turns to engage the T-case, the possibilities are endless, you could actually pull the motor and make it manual engagement and switch to manual locking hubs.... I think it might be difficult to wire a switch or pot to the motor itself because your timing might be off and you could end up overshooting your desired gear

 

The 98 Expedition has A4WD, just like the Navigator.

 

My 98 Expy has 2H, A4WD, 4H and 4L while my Navigator has A4WD, 4H and 4L. What I'm looking to do is add the ability to have 2H for highway cruising. This is not due to any problem, it's just that I like to have the option of which range I'm in.

 

A4WD (Automatic 4 Wheel Drive, not All Wheel Drive) and 2H are basically the same thing. With A4WD you only get power to the rear wheels unless they spin. If rear wheel spin is detected, power is then sent (Automatically) to the front axle to help regain traction.

 

Every once in a while I like to light 'em up. That's why I want the option of 2WD.

 

You could prolly pull the 10 amp fuse that feeds the TOD (Torque On Demand) Relay.

 

Heck, if you got the Intech in that Navi, it should be able to light all four of them up.

 

I recall reading that others here installed a switch in the circuit coming off the A4WD fuse. Turning the switch off prevents the front clutch from engaging. Turn the switch on and everything is back to normal.

 

That sounds like the way I will go, but as the switch in the Expidetion looks just like the one in the navigator my thought was if changing the switch and adding 1 wire would do the trick. I'm not thinking about mileage as I'm not unhappy with what I'm getting. Thanks for the info alloro.

 

I believe that's been tried and it doesn't work. That selector switch runs to the 4WD module and isn't just a normal 3 or 4 position rotary switch.

 

How about changing the module and the switch?

 

You could look each of them up and cross reference part numbers, but I bet you could change the switch and module to disnegage the A4WD.

Now if you changed the front diff set up to resemble the F150s of the period, they use vacuum to disengage the front driveshaft at the diff. That, in theory, should save a little. In my experience, the F150 with the disengage doesn't do any better on fuel anyway.

Does the Expy with the 2H position disengage the front shaft? An easy check is to try to turn the shaft while in 2H and parked.

Burnouts....awesome.

 

On the 98 with the 2H position I think it does have the vacuum actuators to disengage the shaft.

 

You're correct, it does.