'97 Control Trac Problem--Won't Disengage 4WD

I have a 1997 Control Trac 4.0L OHV with about 130,000 miles on it.

With the selector set on Auto (choices are Auto, 4H and 4L) 4WD is engaged
all the time. This is based upon the fact that it's clumping while turning,
even on hard dirt (almost new Michelin LTX tires). I did the 'ol clean the
transfer case sensors trick and it didn't help. I think the transfer case
clutch is engaged all the time but I cannot find a description of the TC
clutch either in my Hayne's manual, online, or in my Ford Service Manual on
CD. The Ford manual doesn't seem to have this particular problem listed
under their diagnostic procedures.

My understanding is that the front differential on the vehicle is a regular
"live"open differential and there are no locking hubs. Is this correct?
That might explain why one front wheel was spinning while attempting a
steep, muddy hill. This kinda stinks if this is the case. Maybe it's time
to trade it in on a first generation Explorer.

I removed the servo motor to get to one of the sensors and noticed that the
TC choices are H, L, and N. On the 91-94s the choices are 2H, 2L, and 4L.
I could not find a position where 4WD was not engaged.

The rear seal on the transfer case is leaking. The fluid looks rather dark.
Is it possible that the fluid was contanimated through a minor leak in the
seal? Could this be causing the sensors to not work at all? I changed the
TC fluid 25,000 miles ago or thereabouts. I suspect that new fluid would
probably become dirty soon so is there such a thing as flushing a transfer
case? Of course a new seal is imperative.

There is a minor to moderate whine from somewhere around the middle to the
front of the vehicle that is constant at a constant speed. It does not
change while accelerating/decelerating. There is a slight clunk when coming
to a stop, either in D or R. If it had radius arms I'd think it needed new
bushings. I've read a lot about replacing ball joints but don't recall the
symptoms. Is clunking a sign of bad ball joints, or perhaps bad CV joints?
Could worn wheel bearings somehow cause the Contro Trac to go wacky? Or is
this whine somehow related to the transfer case problem?

I disconnected the wiring going to the transfer case and 4WD is now
disengaged. Is there any problem with driving it with the TC wires
disconnected? I've read about the "brown wire" but that wouldn't really fix
the problem--it would just make it go away.

I'm going to try to get the codes read but this car is not here most of the
time (daughter's car) and unless she crawls underneath and reconnects the TC
wiring before getting them read I suspect the code info would be erroneous.

Are you saying that you want the 4WD to be disengaged when the selector
is in auto position? As Control Trac was explained to me when I got my
'98, all selector positions have 4 WD working all the time. In fact in
my state(NY), these vehicles are exempt from part of the annual
emissions test because of the full time 4 WD. I also recall that when
the Expedition came out, being one notch above pricewise, it had an
additional selector choice which put it in 2 WD.

Ulysses wrote:
> I have a 1997 Control Trac 4.0L OHV with about 130,000 miles on it.
>
> With the selector set on Auto (choices are Auto, 4H and 4L) 4WD is engaged
> all the time. This is based upon the fact that it's clumping while turning,
> even on hard dirt (almost new Michelin LTX tires). I did the 'ol clean the
> transfer case sensors trick and it didn't help. I think the transfer case
> clutch is engaged all the time but I cannot find a description of the TC
> clutch either in my Hayne's manual, online, or in my Ford Service Manual on
> CD. The Ford manual doesn't seem to have this particular problem listed
> under their diagnostic procedures.
>
> My understanding is that the front differential on the vehicle is a regular
> "live"open differential and there are no locking hubs. Is this correct?
> That might explain why one front wheel was spinning while attempting a
> steep, muddy hill. This kinda stinks if this is the case. Maybe it's time
> to trade it in on a first generation Explorer.
>
> I removed the servo motor to get to one of the sensors and noticed that the
> TC choices are H, L, and N. On the 91-94s the choices are 2H, 2L, and 4L.
> I could not find a position where 4WD was not engaged.
>
> The rear seal on the transfer case is leaking. The fluid looks rather dark.
> Is it possible that the fluid was contanimated through a minor leak in the
> seal? Could this be causing the sensors to not work at all? I changed the
> TC fluid 25,000 miles ago or thereabouts. I suspect that new fluid would
> probably become dirty soon so is there such a thing as flushing a transfer
> case? Of course a new seal is imperative.
>
> There is a minor to moderate whine from somewhere around the middle to the
> front of the vehicle that is constant at a constant speed. It does not
> change while accelerating/decelerating. There is a slight clunk when coming
> to a stop, either in D or R. If it had radius arms I'd think it needed new
> bushings. I've read a lot about replacing ball joints but don't recall the
> symptoms. Is clunking a sign of bad ball joints, or perhaps bad CV joints?
> Could worn wheel bearings somehow cause the Contro Trac to go wacky? Or is
> this whine somehow related to the transfer case problem?
>
> I disconnected the wiring going to the transfer case and 4WD is now
> disengaged. Is there any problem with driving it with the TC wires
> disconnected? I've read about the "brown wire" but that wouldn't really fix
> the problem--it would just make it go away.
>
> I'm going to try to get the codes read but this car is not here most of the
> time (daughter's car) and unless she crawls underneath and reconnects the TC
> wiring before getting them read I suspect the code info would be erroneous.
>
>

"Kenneth J. Harris" > wrote in message
...
> Are you saying that you want the 4WD to be disengaged when the selector
> is in auto position? As Control Trac was explained to me when I got my
> '98, all selector positions have 4 WD working all the time. In fact in
> my state(NY), these vehicles are exempt from part of the annual
> emissions test because of the full time 4 WD. I also recall that when
> the Expedition came out, being one notch above pricewise, it had an
> additional selector choice which put it in 2 WD.
>

Yes, I want it to be disengaged when turning on pavement and hard dirt etc.
It *used* to work now apparently the electromagnet clutch inside the
transfer case is engaged all the time. At least that's what seems to be the
problem. If I don't fix it I fear that other things in the front are going
to break. My older Explorers have a 2WD setting. When Control Trac works
it seems to work quite well (according to my daughters who says she almost
never has to turn the switch no matter how bad the road is).

I have found many posts about disconnecting the "Brown Wire" that activates
the TC clutch but the only thing I've found so far about actually fixing it
is to clean the sensors. I gather that (other than the clutch problem) many
of the guys who do the brown wire trick just want to be able to leave major
portions of their rear tires on the pavement. Somebody else must be paying
for them.


> Ulysses wrote:
> > I have a 1997 Control Trac 4.0L OHV with about 130,000 miles on it.
> >
> > With the selector set on Auto (choices are Auto, 4H and 4L) 4WD is
engaged
> > all the time. This is based upon the fact that it's clumping while
turning,
> > even on hard dirt (almost new Michelin LTX tires). I did the 'ol clean
the
> > transfer case sensors trick and it didn't help. I think the transfer
case
> > clutch is engaged all the time but I cannot find a description of the TC
> > clutch either in my Hayne's manual, online, or in my Ford Service Manual
on
> > CD. The Ford manual doesn't seem to have this particular problem listed
> > under their diagnostic procedures.
> >
> > My understanding is that the front differential on the vehicle is a
regular
> > "live"open differential and there are no locking hubs. Is this correct?
> > That might explain why one front wheel was spinning while attempting a
> > steep, muddy hill. This kinda stinks if this is the case. Maybe it's
time
> > to trade it in on a first generation Explorer.
> >
> > I removed the servo motor to get to one of the sensors and noticed that
the
> > TC choices are H, L, and N. On the 91-94s the choices are 2H, 2L, and
4L.
> > I could not find a position where 4WD was not engaged.
> >
> > The rear seal on the transfer case is leaking. The fluid looks rather
dark.
> > Is it possible that the fluid was contanimated through a minor leak in
the
> > seal? Could this be causing the sensors to not work at all? I changed
the
> > TC fluid 25,000 miles ago or thereabouts. I suspect that new fluid
would
> > probably become dirty soon so is there such a thing as flushing a
transfer
> > case? Of course a new seal is imperative.
> >
> > There is a minor to moderate whine from somewhere around the middle to
the
> > front of the vehicle that is constant at a constant speed. It does not
> > change while accelerating/decelerating. There is a slight clunk when
coming
> > to a stop, either in D or R. If it had radius arms I'd think it needed
new
> > bushings. I've read a lot about replacing ball joints but don't recall
the
> > symptoms. Is clunking a sign of bad ball joints, or perhaps bad CV
joints?
> > Could worn wheel bearings somehow cause the Contro Trac to go wacky? Or
is
> > this whine somehow related to the transfer case problem?
> >
> > I disconnected the wiring going to the transfer case and 4WD is now
> > disengaged. Is there any problem with driving it with the TC wires
> > disconnected? I've read about the "brown wire" but that wouldn't really
fix
> > the problem--it would just make it go away.
> >
> > I'm going to try to get the codes read but this car is not here most of
the
> > time (daughter's car) and unless she crawls underneath and reconnects
the TC
> > wiring before getting them read I suspect the code info would be
erroneous.
> >
> >

"Ulysses" > wrote in message
...
>
> "Kenneth J. Harris" > wrote in message
> ...
> > Are you saying that you want the 4WD to be disengaged when the selector
> > is in auto position? As Control Trac was explained to me when I got my
> > '98, all selector positions have 4 WD working all the time. In fact in
> > my state(NY), these vehicles are exempt from part of the annual
> > emissions test because of the full time 4 WD. I also recall that when
> > the Expedition came out, being one notch above pricewise, it had an
> > additional selector choice which put it in 2 WD.
> >
>
> Yes, I want it to be disengaged when turning on pavement and hard dirt
etc.
> It *used* to work now apparently the electromagnet clutch inside the
> transfer case is engaged all the time. At least that's what seems to be
the
> problem. If I don't fix it I fear that other things in the front are
going
> to break. My older Explorers have a 2WD setting. When Control Trac works
> it seems to work quite well (according to my daughters who says she almost
> never has to turn the switch no matter how bad the road is).
>
> I have found many posts about disconnecting the "Brown Wire" that
activates
> the TC clutch but the only thing I've found so far about actually fixing
it
> is to clean the sensors. I gather that (other than the clutch problem)
many
> of the guys who do the brown wire trick just want to be able to leave
major
> portions of their rear tires on the pavement. Somebody else must be
paying
> for them.

Just for posterity, the transfer case rear output seal was leaking. I
finally managed to get all the stuff together and replaced it yesterday.
With no leaks and new ATF the Control Trac now seems to work properly again.
I did clean the upper sensor again because it was easy to get to. The old
fluid was a bit dark but still transparent. It was low on fluid and I had
been checking it regularly and filling it as needed but the leak must have
suddenly gotten worse. BTW you need a 30mm thinwall socket to remove the
yoke nut from the transfer case--a regular socket will not fit inside the
flange.

I have also been told that the front ABS sensors might have an effect upon
the Control Trac system. My ABS light was not on and seemed to be
functioning properly but if the new fluid and seal didn't work that seemed
to be the next thing to look at.

>
>
> > Ulysses wrote:
> > > I have a 1997 Control Trac 4.0L OHV with about 130,000 miles on it.
> > >
> > > With the selector set on Auto (choices are Auto, 4H and 4L) 4WD is
> engaged
> > > all the time. This is based upon the fact that it's clumping while
> turning,
> > > even on hard dirt (almost new Michelin LTX tires). I did the 'ol
clean
> the
> > > transfer case sensors trick and it didn't help. I think the transfer
> case
> > > clutch is engaged all the time but I cannot find a description of the
TC
> > > clutch either in my Hayne's manual, online, or in my Ford Service
Manual
> on
> > > CD. The Ford manual doesn't seem to have this particular problem
listed
> > > under their diagnostic procedures.
> > >
> > > My understanding is that the front differential on the vehicle is a
> regular
> > > "live"open differential and there are no locking hubs. Is this
correct?
> > > That might explain why one front wheel was spinning while attempting a
> > > steep, muddy hill. This kinda stinks if this is the case. Maybe it's
> time
> > > to trade it in on a first generation Explorer.
> > >
> > > I removed the servo motor to get to one of the sensors and noticed
that
> the
> > > TC choices are H, L, and N. On the 91-94s the choices are 2H, 2L, and
> 4L.
> > > I could not find a position where 4WD was not engaged.
> > >
> > > The rear seal on the transfer case is leaking. The fluid looks rather
> dark.
> > > Is it possible that the fluid was contanimated through a minor leak in
> the
> > > seal? Could this be causing the sensors to not work at all? I
changed
> the
> > > TC fluid 25,000 miles ago or thereabouts. I suspect that new fluid
> would
> > > probably become dirty soon so is there such a thing as flushing a
> transfer
> > > case? Of course a new seal is imperative.
> > >
> > > There is a minor to moderate whine from somewhere around the middle to
> the
> > > front of the vehicle that is constant at a constant speed. It does
not
> > > change while accelerating/decelerating. There is a slight clunk when
> coming
> > > to a stop, either in D or R. If it had radius arms I'd think it
needed
> new
> > > bushings. I've read a lot about replacing ball joints but don't
recall
> the
> > > symptoms. Is clunking a sign of bad ball joints, or perhaps bad CV
> joints?
> > > Could worn wheel bearings somehow cause the Contro Trac to go wacky?
Or
> is
> > > this whine somehow related to the transfer case problem?
> > >
> > > I disconnected the wiring going to the transfer case and 4WD is now
> > > disengaged. Is there any problem with driving it with the TC wires
> > > disconnected? I've read about the "brown wire" but that wouldn't
really
> fix
> > > the problem--it would just make it go away.
> > >
> > > I'm going to try to get the codes read but this car is not here most
of
> the
> > > time (daughter's car) and unless she crawls underneath and reconnects
> the TC
> > > wiring before getting them read I suspect the code info would be
> erroneous.
> > >
> > >
>
>