Hey guys, new here but not so new to the F-150. Had a few of them (bought new and used), and been around them quite a while. I've currently got a 1999 F-150 XLT 4x4 with a crappy non PI 4.6, garbage 4R70W trans and the small 8.8 rear, that I'm going to be doing a few things to.

The truck will end up with a 5.4 DOHC out of my 2001 Navigator I just picked up, as well as the 4R100 trans and 3.73 front and rear axles with of course the auto climate control and Navi dash. But when doing all this I figured why not integrate the AWD system from the Navigator. This way I can hammer some auto AWD launches without shock loading the front CV's like the 4x4 currently in my 150 would do. Is this something that's even remotely possible?

I'm having a hard time figuring out exactly how it works, as it seems no one has really done it before. From what I gather there is some sort of computer logic and sensors to run the system, but that's really all I can find. Any info would be greatly appreciated.

TIA

 

computers and harnesses will be the issue....you'll need to find a Ford guru to guide you through the processes....it may be more of a money pit by the time yer done....

 

The main issue is I know there have to be some sensors on the wheels to tell the AWD system what the heck is going on, unless it's a sensor on each driveshaft.

I have been debating pulling all the Navi wiring from the engine/trans and dash as well as the Navi computer (obviously I have to use this computer and trans harness because I'm going to a 4R100) and trying to adapt it to my F-150 (hoping it's plug and play). Then I can basically just take it from the Navi and drop it in my 150 letting it run as a Navigator. Then just go get my Pats system disabled or reprogrammed and program the new PCM for my VIN/cluster and I should be good to go.

 

Don't forget your exhaust crossover needs to move back 5" and you need the crossmember, drive shafts, shift cable and cooler lines for the 4r100 swap. Not 100% needed but the 10.25 rear diff is longer than the 8.8 so the shaft won't be completely splined in if you use everything from the F250 LD or 7700.

 

Oh and you need the longer torsion bars from the F250 or 7700 as well. Best way to do it is with a parts truck, that's how I did it anyways! $500 and I got everything and sold the tires for the same as what I paid!

 

It may or may not come into play that the rear axle on the Expedition is coil spring and the F150 is leaf.

 

It's still shorter and you either use the driveshaft from the 7700 and risk wearing out the rear seal on the t-case or get one built, or replace with a 10.25 rear and redrill for the 5x135 pattern

 

Just so you know. When you engage AWD in the Navi system it locks the front axle and uses electro magnetic clutches in the transfer case to send power to the front. Using the AWD to lessen the shock to the CV joints will just not happen.

 

I agree. Doesn't it detect spin from the rear and engage the front

 

Exhaust I am using off my buddies old 4x4 lightning swapped truck, cross member I wasn't aware of but kinda of had a feeling (will the one from the Navigator work?). Shift cable I'll pull from the Navi, as well as make my own cooler lines because I have an aftermarket trans cooler to hook up. Also as far as the rear I'm probably going to try to find a 3.73 rear from an F-150 (aka the 9.75") because that will be much much easier to bolt up, and I really don't need a 10.25 rear, it's just way overkill.

So the torsion bars are longer for any 4R100 swapped truck? There's a 7700 package truck in my local junkyard, but I don't know how I would even get the torsion bars out without a torch to cut the a arm off. Can I use the ones from the Navigator or are they too light duty? I read there are something like 7 different front torsion bar strengths that got computer selected depending on the duty of the vehicle.

It does; after I did some research and looked at the two axles, I decided all the work needed would not be worth using the Navi rear axle, front should be the same though.

I'm going to be using a 9.75 rear so this shouldn't be an issue.

Ok well that saves a bunch of work then if there is nothing to be gained. I'll just keep the 4x4 in my truck now.

 

You need the driveshafts and from an ext cab to crew are the same. You dont need the 10.25 but the 7700 has them and that will make the correct engagement of splines, I still have my 8.8 but I notice some vibration becsuse its not completely splined in. Im using my 10.25 cuz it was on my parts truck and free. Oh and the wheel base is 138" if I recall. And for the torsion bars, I cut the ones I wasn't going to be using and used them to drive out the other end out of the control arm on the truck and a whole lot of weasle **** to get the longer ones out. It was fairly easy to drop everything off the front end of the parts truck and do it on the driveway

 

What axles can I use in the 10.25 to get back down to the 5 lug pattern? Also are the brakes on the 10.25 the same as regular 150 disk brake rears are or they bigger? Because I have to swap all that over to the 5 lug if I wanted to use the 10.25.

Also when you're talking about the correct engagement of splines, are you talking about the driveshaft or torsion bars? I'm a bit confused as to what you were saying.

 

The brakes are bigger on the 10.25, may have to build custome axles otherwise a custom driveshaft. Sorry I mean the slip yoke will not be as far into the transfercase as it should be.