I`ve got -99 Navigator VIN. 5LMPU28L2XLJ00521, it can be -98?

Formally owner has been some damage with the car and there can be some wrong/missing parts?

1. Should there be 3 or 4 position AWD switch in the dash?
2. Should there be vacuum disconnector in the front axle?
3. If the car is AWD model why there is disconnector?
4. There is two vacuum switch in the firewall, I don`t find any wires to them? Does anyone have Picture of those?

Sorry to my bad English.

 

Can get online owners manuals in this link; may help with some of the questions

https://www.fleet.ford.com/partsands...owner-manuals/


i had a ‘99 Expedition that presumably is basically the same as the Navigator. My recollection on the awd aspect is that there was 10% power going to the front in 2wd/awd.

 

If have all the manuals for the car.
Owners manual and workshop manual.

But, I`ve seen 4 and 3 postion dash switch for the AWD.
And someone are strip parts so there can be wrong parts.

I Still don´t understand what is the meaning front axle disconnect system if adw is allways on?

 

The owners manual should explain the 4wd features

this link from a google search has a short explanation

https://m.awdwiki.com/en/lincoln/

 

I understand how does AWD work. My question was and is:

should there be 4 position switch If there is disconnector in front axle?

If front axle is disconnect and you drive and rear wheels start to slip, transfer moves power to front propeller shaft. Vacuum connector cannot connect front shaft If there is power in front propeller shaft?

 

If you have all the manuals, you really need to study them.

These Navigators are not AWD (All Wheel Drive).
They are A4WD (Automatic 4 Wheel Drive).

AWD vehicle’s can run on hard surfaces with all wheels driving and not cause bind up or break parts when turning.
A4WD vehicles actually run in 2-wheel drive until wheel slippage is detected, at which time the electronic clutch in the transfer case is cycled to transfer some power to the front wheels. As soon as slippage is eliminated the clutch is deactivated.

In the early years of the Navigator/Expedition, some years had a 3 position switch, some had a 4 position switch, the extra position being a 2H position. When in 2 High, vacuum disconnected the front diff and driveshaft from the front wheels/axles.

When In 2-High or 4-High, the electronic clutch in the transfer case is at 100% duty cycle, effectively locking the front and rear driveshafts together. This mode is typically referred to as part-time four wheel drive as it should not be used when on solid surfaces as it will bind up and possibly break stuff when turning, where as full-time four wheel drive allows a differential action to take place in the transfer case, allowing use on both solid and slippery surfaces, thus called “full-time” four-wheel drive.

Hope that helps.

 

1999 has the 3 position switch. No 2wd selection. Only A4wd/4hi/4lo.

 

When 2h and 4h is tranny connect both shafts lock?? You meen 4l and 4h? I dont have 2h so do front axle disconnect ever?

 

You’re correct, I meant 4L and 4H.
And yes, if your vehicle doesn’t 2H, then the front wheels/axles/diff and front driveshaft are always connected, but only receive power when in 4L, 4H, and only When wheel slippage is detected when in A4WD.

 

So, should my car have these vacuum switches in firewall, passenger side? If front axle is allways locked?

 

If it came with the 2H position on the selector switch it should have the vacuum solenoids to connect and disconnect the front axle.

So do the pictures and explanation in your owner’s manual show a 2H position on the selector switch?

 

Only 3 positions in 1999.

 

Ok, thank you all this far.

But.. Still I wonder?

If car is originelly equipment with 3pos 4x4 switch (W/O 2H), is the front axle with vacuum disconnector?
I`m sure that front axle is original.

Please tell me this.
After that I start to search what is that awful noise at transfer or front axle.

 

No...............

 

Ok, then there should be 4pos switch.