XLT 98' no 4x4.... just another thead...

[jmvb]

Well, I found in the worst way that my 4x4 is not working
in the last weekend travel to the Chilean mountains, as never before, I suffer with some easy off road tracks.
I finally went stuck, and just with the previously installed winch, a stock lift jack and my wife help, I could go back.
The dashboard lights turn on in hi and low mode, I can hear the transfer motor working (was changed new recently), but I'm pretty sure that the front train is not driving.
If I engage the LOW, the torque difference is noticeable.

For some reason, the transfer clutch is not engaging.

Where should I start to check?

 

[96eb96]

If you can download http://forscan.org/download.html, use an OBDII adpater, read the GEM codes, it will give us clues where to look. Maybe a bad speed sensor? You can check resistance of both sensors and report back.

 

[jmvb]

Hi 96ag96

I have a scanner, but I have no codes so far and no check engine light on...

BTW: what sensors do you mean?

 

[96eb96]

Can your scanner read GEM codes? Check engine light has nothing to do with 4x4. The link I gave you can read the 4x4 computer and do tests. If the lights blink, you very likely have codes.

There are two sensors in your transfer case - an input and output speed shaft sensor.

They share wiring with the shift motor. There is also a brown wire that controls the clutch that gives 4x4. The way the system works is the more different the two sensors are in speed the more current the brown wire gets (and that powers the front axle).

If a sensor is open or shorted, you would lose 4x4 and get a code.

 

[jmvb]

96ab96

Thank you for take a time and post here

I mean, I have no lights blinking in the dashboard at all. The 4x4 lights behavior is normal

This is my exact problem

http://www.explorerforum.com/forums...t-driveshaft-wont-engage.441481/#post-3511708

I'll test the brown wire and the sensors

 

[96eb96]

Yes, apply voltage manually and see what happens. If it works the switch or sensor is bad. In your case check for voltage (96 is a bit different, I don't have a 4hi, just auto and 4 low).

 

[jmvb]

How can I apply the voltage manually? you mean, apply to the brown wire? how many volts?

 

[jmvb]

Today, I put the explorer in the air, the 4 wheels lifted

Engaged the 4 hi, gear in 1, all wheels moving....
Engaged the 4 low, gear in 1, all wheels moving fine also... WTF!!

We take the explorer to a unpaved road
4x2 and full gas, the rear tires slip a lot
4x4 HI + full gas, the truck out very fast, no slip at all
4x4 LO + full gas, the truck out like a rocket!
WTF!!!

I have proof that the front wheels didn't do anything the last weekend



Any clue?

 

[Mbrooks420]

The TOD (torque on demand)clutch used to slip in my 96 when it was worked hard. It made a clicking sound, however.

 

[jmvb]

The TOD (torque on demand)clutch used to slip in my 96 when it was worked hard. It made a clicking sound, however.

Hi Mbrooks420, can you explain more, please?

 

[Mbrooks420]

I used to drive long distance on no winter maintenance roads. Sometimes 10 or more miles long, and with deep snow in the winter, and heavy mud when it thawed. If we made several trips down, or it was particilarly bad the clutch would slip inside the transfer case ( that allows for the "automatic" 4wd function). It is electromagnetic and cycles as the truck detects wheel slippage. In low the clutch locks the front and rear axles together. In low, only one front tire will spin under load, due to the open differential. Both back tires can drive, depending on which rear axle you have. When it slipped, It would make an audible clicking sound, and the front drive would become jerky.

 

[jmvb]

Ok, that would explain why in the shop, with the engine and transfer case relative cold, the 4x4 works fine and why in the mountains, with about 2 hours of climbing road and 30 minutes off road, engine and transfer hot, the TOD clutch do slip.

Now, how can I repair it?

 

[Mbrooks420]

Can you hear it clicking? It was fairly obvious. Unfortunately, it might be cheaper to replace the case.

 

[jmvb]

Mbrooks420, no I did not... I just don't have front wheels drive after a while to medium- hard off road..