Since my 99 F150 keeps spitting plugs out, and I have a growing family (big malamute and a godson), I'm looking to buy a 03-04 Navigator with the Ultimate package. My question/concern is this: If I get a 2WD, it has the Advancetrac system standard which means it has a NON-Limited Slip Rearend. I understand how the system works while the vehicle is moving, but if you are parked or stopped at a red light, will the vehicle just spin one tire and get stuck, or will it move? I ask this because I live in Colorado but the daily drive to work normally is not bad in snowy weather. The side streets normally are covered in 4" of snow. Will I be getting stuck at every stop sign with advancetrac in the snow?

 

I don't have a navi, just bought an awd aviator of the same era with a version of the traction control, and was disappointed to learn that it had an open rear diff. My experience with its traction control and the one in my 01 mustang has me actively looking for permanent defeats for both systems (plan on a posi or locker in the aviator), as the systems step in WAY to early and too often. The slightest slip and they cut the throttle and/or apply the brake, which to me make them overly unpredictable, especially on a wet cloverleaf.

 

wiki:Two-wheel drive was standard on the Navigator with the available ControlTrac 4-wheel drive system offered as an option. ControlTrac initially included four modes: 2 High, Auto, 4 High (lock) and 4 Low (lock) -:1st generation, navigator and didnt say anything about the 03-06 but i think u should get a 05 or 06 for the 6speed 2 save some MPGS

 

5.4T - The reason I'm looking at the 03-04 is because it is the last years of the 4V DOHC 5.4. I am not a fan at all of the 5.4 3V, its my personal opinion and I'll never own one. I spent a few years as a service adviser and part of my job was also used car recon, and from my experience the 3V is an engine to stay away from until 2008. I spent 2 years trying to keep spark plugs IN my 99 5.4, I don't want to spend another 2 years trying to get them out of the 05-07 5.4, haha. I also do not want to deal with the cam phaser issues the 3V 5.4 have continually shown a tendency for failure. The last thing I don't want to deal with is the drive by wire set up the Navi/Expy had from 05-present. The only advantage of the 05-present is what you mentioned, the 6sp tranny, that would definitely save gas mileage.
The 2WD 'luxury' package navi did not come standard with advance trac but it has a limited slip rear end. If you got the 'premium or luxury' package that got advance trac standard which eliminates the limited slip rear end. I am worried that if I have a 2WD with advance trac, that if I'm at a red light sitting in 4" of snow, will the vehicle just spin the right rear wheel, or is there a trick to the system that prevents that