Newbie Control-Trac question

[oregonsixteen]

I've been googling for technical info on the control-trac system and have been pieceing the fragmented information together. I'm hoping that someone can correct me if I got it wrong.

4x4 Auto = RWD, sensors will tell the computer to share power with the front

4x4 High = 50% power goes to the front, front hubs locks

4x4 Low = Same as 4x4 High but transfer case reduces the ratio by some 2.8

Can someone please tell me how reliable is the electrical/electronics used in 4x4 Auto? Has anyone suffered a sensor failure, etc?????? Thanks!!!!

 

[IAmTodd]

Fairly reliable.

You have no hubs, front is always locked. Uses a magnetic clutch in the transfer case to "vary" the amount of power to the front. There is a true 2WD mod. search on THIS site for the "brown wire mod".

 

[oregonsixteen]

I searched for "brown wire" only to find someone who has also searched for brown wire but couldn't find the mod. Care to share a link?

 

[BrandonB8]

Enjoy... Read the whole thing... some say it helps gas mileage some say it doesn't.

http://www.explorerforum.com/forums/showthread.php?t=41956&highlight=4hi+4lo+4auto

 

[oregonsixteen]

Thanks! But it looks more like a "yellow wire mod" to me.

 

[gijoecam]

Read the WHOLE THREAD. It's the brown wire mod. The yellow wire doesn't work right.

If I remember correctly, I think the mod on an '02 will cause the 4x4 lights to start blinking. It has to do with the way the clutch now grounds through the GEM instead of through the chassis. I was working on a possible way to fool it, but the guy that was doing it never got back to me with the info, so I never had a chance to see if the method would work.

-Joe

 

[oregonsixteen]

Fairly reliable.

You have no hubs, front is always locked. Uses a magnetic clutch in the transfer case to "vary" the amount of power to the front. There is a true 2WD mod. search on THIS site for the "brown wire mod".

Is there a way to mod the front with manual locking hubs? Or is that impossible for an '02 Explorer?

 

[oregonsixteen]

Whew! That was a long thread, I've not finished reading it yet. But at least I got to the part where "brown wire" becomes the focus.

Read the WHOLE THREAD. It's the brown wire mod. The yellow wire doesn't work right.

If I remember correctly, I think the mod on an '02 will cause the 4x4 lights to start blinking. It has to do with the way the clutch now grounds through the GEM instead of through the chassis. I was working on a possible way to fool it, but the guy that was doing it never got back to me with the info, so I never had a chance to see if the method would work.

-Joe

 

[gijoecam]

Indeed..... but don't stop there.... there is another thread (and unfortunately I can't recall who started it, but I was involved in it) that discusses the problem it causes on the '02.

If you just clip the wire and install the switch, the GEM doesn't get the feedback from the clutch coil, thinks something's broken, and flashes the lights (or at least that's what it did to him on his '02). I think an SPST on-on switch (instead of a regular on-off switch) which 'bypasses' the coil *might* make it work, but I would need to know how much current flows through it and in which direction to be sure. The other guy was supposed to find that out for me, but never did, so the discussion stagnated there.

Any volunteers to be the guinea pig? My offer still stands to anyone willing to bring it to me.... I promise I won't cut anything without knowing for sure it'll work.

-Joe

 

[gijoecam]

Is there a way to mod the front with manual locking hubs? Or is that impossible for an '02 Explorer?

And yes, it is impossible.

-Joe

 

[oregonsixteen]

And yes, it is impossible.

-Joe

Hmmmmmmm..... which keywords should I use to search for more technical data for the front wheels? I tried "ford+explorer+front+wheels" and a few variations on google and it gave me a bunch of garbage.

 

[gijoecam]

Search for Ford Truck Service CD on Ebay. Select the appropriate CD for your model year, and make sure it's an official Ford CD, not a Chilton or Haynes. Study the information and ask a lot of questions.

The second generations Explorers use a completely different suspension and driveline setup than the original Shift On the Fly setups Ford used. They essentially have a hub and CV shaft like a front wheel drive vehicle connected to a shortened reverse rotation Dana 35 axle. The early 2nd gens (95 and 96 specifically) used a vacuum-actuated center-axle disconnect to break the passenger side axle shaft, preventing the front driveshaft from needing to rotate at all times. What they found after extensive testing was that the driveshaft tended to rotate anyways due to the fluid viscosity in the transfer case and differential, and it was more unnecessary components that could fail in the 4x4 system. They also discovered that the new Borg Warner transfer case design could take full-power applications without failure, and so they refined the system.

The '97 model year saw the elimination of the center-axle disconnect and the elimination of the true 2wd setting, leaving us with 4 auto. Essentially, it locked the solid axle in place, using the transfer case alone to engage and disengage the front driveline. It works, and works well, but some of us control freaks wanted true 2wd, hence, the introduction of the infamous "Brown Wire Mod". (It has other applications, but it's a looooong thread.... good rainy-day reading)

I think that about covers the basics in a nut-shell. Got any more questions?

-Joe

 

[oregonsixteen]

thanks, that was great info. i take it that the 02-05 models use the same system as the 97 right?

 

[gijoecam]

In terms of the drivetrain, yeah, pretty much. Completely different suspension setup though. And I still haven't figured out the whole AdvanceTrac with Roll Stability Control just yet, but I'm working on it.

-Joe