'98 Control Trac Transfer Case Problem!

[section525]

Okay, the 4WD stopped working on my GFs '98 Sport while we were up in the snow last weekend. The lights would indicate it was in 4WD and 4WD LOW but it was obviously not. While the back tires were spinning, it would make a weird clicking noise (as if something was broken; sort of like a baseball card in your spokes sort of deal). So I jacked it up off all fours today and found that the front drive shaft was not turning. The rear axle would work in all gears (including 4LOW).

So, the lights are not flashing, it is obviously shifting into gear, but the front shaft is not turning. How can I find whether this is an internal or external tcase problem? What do you guys think it is or as anyone had this problem before?

Thanks!

 

[Doug]

Sounds like the TOD clutch in the transfer case. This is what basically engages the front driveshaft when you put it into 4wd. The samething happened to me with my 97. I ended up swapping it out for a bw 1354 manual shift t-case.

 

[dogfriend]

I ran across this article while looking for info on the Control Trac transfer case:

www.atra-gears.com/gears/2002-09/2002_09_60.pdf

Hopefully this isn't the problem, but it sounds like a possibility.


This unit is prone to certain
mechanical problems that are beyond
the scope of most shops to repair. The
most common mechanical failure is a
complaint of a loss of drive accompa-
nied by a ratcheting noise coming from
the transfer case during coast or decel-
eration or when in reverse. Careful
questioning of the driver will reveal that
this condition was preceded by an occa-
sional thump from the transfer case at a
constant road speed of 40-60 MPH.
When you disassemble the transfer case
you will find that the range hub and
range fork will be damaged, but replac-
ing these items will not solve the prob-
lem. The range hub is helical cut gear-
ing and will stay in mesh under load,
but will move out on coast due to the
thrust loads generated by the helical
design. Adding power will cause the
gear to return to the correct position.
The bottom of the teeth get chewed up
and the constant pressure on the fork
causes it to burn up. The real cause of
the problem is an offset in the centerline
distance, putting the shift rail at an
angle, which allows the range fork to
move out of position. The cases are
magnesium and we do considerable
machine work to correct this problem,
which is beyond the equipment found in
the average shop. If you see units with
this damage, you will usually see
oblong holes in the cases where the
shift rail rides. It is cheaper and more
efficient to buy a unit that has this
problem corrected than to tackle it
yourself.

 

[John 95XLT 4.0L]

I have that type of noise in my 95. When I decellerate from about 100km or 60mph it will start that wirrrrring noise until I either put drive on it by applying gas or it does not seem to do it when I am decellerating but doing so quickly with the barkes applied. We just bought this vehicle a couple off weeks ago and it is going to the gargage on Wed. for repair so I will have to wait and see what they say. They have preliminarily said it could be a wheel bearing but I think the noise is coming from the transfer case.

 

[section525]

Anyone else have any ideas here. Apparently the transfer case wasn't making any odd noises prior to it not working anymore. Infact, I was the one driving it when it went out.

What else could it be? Hubs? I'm going to tear into this thing this weekend if I have to!

Thanks!

 

[TPLYNCH]

Sounds like the T/F case itself is toast. I think there is a chain in there. That may have snapped.

 

[annabanana]

Okay.. we just jacked it up on all fours and three of the tires spin in 4WD. Which I think is a very good sign. So, it sounds like I have a hub out, right? The right front is the only one not turning. I'm going to go clean all the speed sensors and electrical connections anyway.. but does it sound like I have a bad hub?? Thanks!

 

[TarHeel085]

Originally posted by annabanana
Okay.. we just jacked it up on all fours and three of the tires spin in 4WD. Which I think is a very good sign. So, it sounds like I have a hub out, right? The right front is the only one not turning. I'm going to go clean all the speed sensors and electrical connections anyway.. but does it sound like I have a bad hub?? Thanks!

no, you prob just have a LS in the rear and that way both tires spin in the back, but you dont in the front so only 1 spins. ask John he'll be able to explain it a little better if thats unclear.

 

[section525]

Okay.. heres the deal. It works when the truck is off the ground.. but when its on the ground the front shaft will not spin. Sound like the TOD clutch.. or could it be something else?

 

[dogfriend]

If it turns when in the air, but doesn't work normally, it does seem like the transfer case clutch could be bad. They are supposed to be pretty rugged, but topo4u2 had a similar problem with his 95, which was probably aided by someone putting the wrong lube into the transfer case: Dead Link Removed

In his case, the dealer replaced his original t-case with one that the clutch didn't work right. He didn't ever fix the problem, he traded it in on another 4wd truck.