1998 xlt transfer case questions

[whitebread]

quick rundown:
1998 explorer xlt 4.0 ohv, auto transfer case with the switchable auto/4 hi/4 lo.

we got hit with a snowmagedden here in NC this weekend, and the 4 wheel drive worked fine most of the day sunday, and after almost getting stuck trying to get around an idiot stuck in the MIDDLE of a 2 lane rd, I soon noticed that the front wheels were no longer pulling.... I never heard anything break, and I drove today in 2wd without any noises or issues...

in the past, shifting it into 4 low, it would give a good "clunk" but go in without problems, 4 high would shift in without noise and work fine. I can still hear the case engage, but won't drive the wheels. I jacked up one front wheel tonight after I got home, grabbed the shaft at the cv joint, and while in park, I was able to spint the front wheel with the shaft...

I looked at the transfer case thread, but only got confused. I'm not sure which transfer case mine has, and not being full AWD, if mine has a fluid coupler or not. I'm used to the older transfer cases that if the chain snaps, you go nowhere, and if the chain snaps in this unit, will it still pull itself? should I be able to turn the front shaft (with one wheel off the ground) with the trans in park? I've heard that the trans is slightly different from an ohv to a sohc engine, is the transfer case the same, or do I need to find one from an ohv unit if I go the junkyard route?

I'm an ex mechanic, so I have some knowledge, but I'm not a off-roader, so I'm not really immersed in transfer cases. any help pointing me in the right direction would be extremely helpful and appreciated!

thanks in advance,
Darin

 

[XLTrunner]

Both the OHV and SOHC engines with auto have the Borg Warner 4405 transfer case. You do not have a fluid coupler like on the AWD vehicles. But, just so you know, there normally is always a small percentage of power being directed to the front driveline...even in Auto mode. That is why it's imperative you run the same brand/size tires with equal tread depth and tire pressures to avoid damaging the t.c. Could be several things causing the front driveline to not engage. Here is a link explaining how a t.c. works:
The Borg Warner 4405 Transfer Case Rebuild Diary

 

[whitebread]

thank you for the link, somehow I was reading the wrong thread earlier.... I may just get another TC from one of the yards I go to, and attempt the rebuild on my original.... being I only have about $500 in the entire explorer, spending a little on it won't really hurt!

 

[Mbrooks420]

Your most likely have a damaged clutch.

There is no shifting at all between Auto and high, it simply powers that clutch.

 

[drdoom]

To answer your question about the front wheel... I believe you have an open differential up front, so what you describe is normal.

 

[drdoom]

You may want to check the electrical connector at the T-case, and also the TOD fuse. If you want to go a little further, back probe the brown wire at the case. At zero duty the reading should be approximately 0.6VDC, at full duty it should read just under 6VDC.

 

[Cowboytrukr]

Drdoom, you’re right. I’ve had mine up on jack stands and in 4WD, I can hold the front wheel and easily prevent it from spinning. Definitely normal open diff.

Tcase clutch pack possibly damaged.

 

[whitebread]

hoping to pick up a used tc at the yard this weekend, and I'll tear into this one in the next week or so...

I will check the wiring before taking the whole shebang out though! thank you for the hint!

 

[whitebread]

To answer your question about the front wheel... I believe you have an open differential up front, so what you describe is normal.

I do have an open front diff (I had to replace the front unit last summer- luckily found the right gear ratio carrier on the second explorer) but my concern was that I was able to turn the front shaft with one wheel off the ground... I was thinking that it shouldn't have allowed the driveshaft to turn, but I'm understanding the operation a bit better now.

 

[Cowboytrukr]

Yes, that’s normal.

 

[974X4BLACKSPORT]

The little plastic bushings on the shift fork in the transfer case are probably broken, that would give the "clunk" noise when engaging.

 

[rasouth]

I had a similar problem with my transfer case. It would not switch into 4WD at all and at times would make a loud squealing noise that would stop if I stepped on the gas. It was the nylon pads on the shift fork AND the fluid inside had dried up into a crust. Cleaned off crust and replaced pads. Cost was less than a hundred, including fluid for TC.

 

[whitebread]

I appreciate the replies everyone! after reading through the rebuild thread, I'm understanding how this unit operates, and the how the suggestions relate to the components... I will keep the original unit instead of returning it to the JY for the core, and tear it down, and rebuild it in the near future. I will post up the result of what I find, as I get frustrated when posters never let you know if your suggestions fixed the problem or not!

 

[drdoom]

I appreciate the replies everyone! after reading through the rebuild thread, I'm understanding how this unit operates, and the how the suggestions relate to the components... I will keep the original unit instead of returning it to the JY for the core, and tear it down, and rebuild it in the near future. I will post up the result of what I find, as I get frustrated when posters never let you know if your suggestions fixed the problem or not!

Good call. I have successfully rebuilt several 4405 transfer cases, they are actually quite simple internally. I highly recommend the SONNAX shift fork roller upgrade, and if you know a good machinist, having the case halves sleeved at the shift rail is very important also. Also very important is keeping clean fluid in there. I have heard a couple of folks say that "well I never use 4WD"... doesn't matter, every time a wheel turns the pump is running.

Best wishes,
Doc

EDIT: Darin, I keep going back to your original post, and how it seems to point to an electrical or electronic fault. I still urge you to do an electrical diagnosis. The two reasons I say this are, from your OP: no clunk, which points to the shift encoder motor, and front wheels not pulling, which points to the electromagnetic clutch.
Question, are you getting LOW range?

 

[fast_dave]

Just saying if you want to start simple - since you say that things were working and then suddenly stopped working.

Dunno' if this has anything to do with it, but it's pretty simple to check/rule out.

If you're transfer case has never been serviced, there is an electric speed sensor on the rear of the transfer case. There might even be two speed sensors on the 4405 - I can't remember as I'm only on my first cup of coffee - but the sensors have electrical wires going to them, so they're easy to find.

Over the years, this speed sensor gets a build up of metal shavings on it - the same condition that the ABS Sensors in your rear pumpkin and front hubs.

Wipe it off, reinstall, and see if that helps -

HTH and Merry Christmas & Happy New Year!

 

[whitebread]

EDIT: Darin, I keep going back to your original post, and how it seems to point to an electrical or electronic fault. I still urge you to do an electrical diagnosis. The two reasons I say this are, from your OP: no clunk, which points to the shift encoder motor, and front wheels not pulling, which points to the electromagnetic clutch.
Question, are you getting LOW range?

I was getting a "clunk" when I would shift into low range, stopped doing it a short time before 4x went out... when I switch into 4high or 4 low, you can hear the motor engage, but no power goes to the front....

Just saying if you want to start simple - since you say that things were working and then suddenly stopped working.

Dunno' if this has anything to do with it, but it's pretty simple to check/rule out.

If you're transfer case has never been serviced, there is an electric speed sensor on the rear of the transfer case. There might even be two speed sensors on the 4405 - I can't remember as I'm only on my first cup of coffee - but the sensors have electrical wires going to them, so they're easy to find.

Over the years, this speed sensor gets a build up of metal shavings on it - the same condition that the ABS Sensors in your rear pumpkin and front hubs.

Wipe it off, reinstall, and see if that helps -

HTH and Merry Christmas & Happy New Year!

I'll def give this a try before I yank anything out! I do have acess to a lift, so I can get a good look at everything.

** my original plan is being put on hold for a slight bit, as I've come across a parts vehicle for one of the many other projects that I've got going right now.... will let you guys know the progress when
i have some!

thanks again!
Darin

 

[fast_dave]

No problem, Darin.

Keep it simple and rule out all you can before doing the heavy work ;-)

Merry Christmas, Happy New Year, and close the loop when it all comes together - that's what makes the forum work!

 

[Mbrooks420]

You should hear nothing when you put it in High as there is zero shifting to do this. The motor only has two positions, high and low.

 

[whitebread]

You should hear nothing when you put it in High as there is zero shifting to do this. The motor only has two positions, high and low.

you're right, it may be my own wires are crossed, and I might have my memory a little askewed.... I'll check it in the morning.

 

[whitebread]

You should hear nothing when you put it in High as there is zero shifting to do this. The motor only has two positions, high and low.

as usual, my memory proved wrong, and no it didn't make any noise... shifting to 4low, however, sounds like an old chevy trying to find second gear....

just wanted to update on this, so y'all wouldn't think I've forgotten it!

I finally got the time to make a junkyard run last weekend, and picked up a unit from another 98 model that looked as though it led a fairly good life... finally got it swapped out yesterday, and 4wd is working much better than what it had before it gave out... still have the old chevy sound with this one, but works really good!

I still plan on at least pulling apart the original unit, and seeing what gave out, and depending on what I find, maybe rebuilding it and putting it back in.....