96 XLT-Front driveshaft turns in 2WD:Normal?? Or bad T-case??

[Oregongreen]

First of all, thank you to those who created this site, and to all who enrich it with information!

I bought a 96 XLT(with 5spd manual) about a week ago, great shape overall, but the price was more than fair since the 4WD has issues. I've spent hours of free time pouring over this website in the last week.

I live on 100 very rural acres, no pavement in my test area, gravel and open moist grassy fields. 4-Auto and 4-Low do engage, and work, but are very noisy. There is a general popping/clunking noise that is non-existent in 4-Low if crawling and going straight, 4-auto seems to be noisy no matter what but the noise increases substantially as more speed and turning is applied. This made me think front diff at that time.

I got excited when I found the sticky concerning troubleshooting 4wd in 2nd Gen Explorers. Even though it seems to be for troubleshooting 4wd that is not engaging at all, and also for Automatics, I decided to give it a try.
I jacked the front of the rig up, and with engine on and the 4wd off tried to spin the front drive shaft, it would not spin as if the T-case was engaged. The wheels would spin freely and were not engaged .
Next I engaged 4-Auto, when I spun the driver side wheel the passenger side spun the opposite direction, this seemed to indicate the passenger side axle is engaging. Then I tried spinning the drive shaft, it wouldn't budge.

After all that, and conferring with my father, we decided it looked like the T-case was permanently stuck in 4WD. Tonight I had my wife move the Explorer in 2wd while I watched the front drive line, it spun. Is it normal for the front drive shaft to turn in 2wd?

When I switch between 4auto and 4low, there is a substantial noticeable difference in gearing, so I'm sure the electronic shifter is at least shifting between the two 4wd modes, and I assume its shifting to 2wd.

Would this leave the T-case it's self as the culprit?

 

[Oregongreen]

Gosh, seems like a easy question, but searches all over this site and the web have yielded no solid answer. Guess I'll look into buying a OEM shop manual, and see if the answer might be there.

 

[drdoom]

Green, I wish I could help more but my rig is a 97 and it has some substantial differences. I will try though, and hopefully someone more knowledgeable can chime in. First, it is my understanding the 96 has a vacuum disconnect on the front axle...can you verify it's operation? Next, the clutch in your caase could seize, possibly keeping it in 4WD. Also, have you had a look at the transfer case fluid? Hope this helps.

 

[Oregongreen]

First, it is my understanding the 96 has a vacuum disconnect on the front axle...can you verify it's operation?

Thanks for posting! By my figuring, if I'm right about the T-case being stuck in 4wd(no matter the position of the selector), the only reason I have 2wd at all is because the vacuum disconnect is very much working. Remember where I said that the wheels free-spin when selector is in 2wd, but spin opposite each-other when in 4wd? This is indicator that the vacuum disconnect is disengaging the passenger side axle for 2wd use.
The concern for me is that even though the disconnect is working, the front driveshaft still won't spin with the wheels off the ground/tranny in N/T-case in 2wd, and actually visibly spins when the rig is under way in 2wd.

So I'm wondering if my observations are a indicator of a malfunctioning T-case or if this behavior is normal for a 5spd man 96 Explorer XLT???

 

[drdoom]

Green, in the 4405 transfer case, there is always going to be a little drag in the electromagnetically activated clutch pack. It is not a 100% disconnect, a small percentage of power is going to the front shaft. So you may be seeing an inherent viscous drag, or still it is possible the clutch pack is blown, and thusly seized. Do you have a fluid sample yet? If that does not come out clean, and you have popping & grinding from THAT area, it could be related in some way. It is an easy case to work on, that much I can tell you, but the vacuum axle I really am not familiar with.

 

[corkey]

the vacuum axle is easy, but i am pretty sure it is not an issue cause as you stated, when up on stands and in 2wd the wheels spun freely,, so that means the vacuum disconnect was in fact disconnected,,
the drive shaft not spinning by hand when in 2wd is the determining factor here,, you said
4wd off tried to spin the front drive shaft, it would not spin as if the T-case was engaged., that tells you the problem is in the t case right away,,

 

[corkey]

how the vacuum axle works is,
when you turn on the 4wd or 4 auto, vacuum from the engine is allowed to flow to a bladder inside a round housing, it sucks the bladder in, and it pulls a splined ring on the outer shaft in towards the middle of the axle locking the two parts together, it is an open diff so when locked if you turn one wheel , the other goes the opposite direction ,

 

[blazin8556]

sure its not a live axle setup? i thought all the 2nd gen explorers were live axle?

 

[J_Train]

No Corkey is right. they used the same thing in Ranger 98-00/01

 

[Oregongreen]

Yep, its a vacuum disconnect, and its working great! All of the other 4wd from my past and present are old fashioned with the manual hubs, and floor shifter, this vacuum disconnect is wicked weird!

My wife was out of town with the rig the last couple days, and I have to work today, but I'm dying to get a fluid sample out of the T-case. I've been pretty sure I was on the right track with the T-case being the problem, but didn't want to throw money the wrong direction without some 2nd opinions/suggestions on further testing.

Thanks for all the feedback guys!

 

[Oregongreen]

OK, so I got a fluid sample out of the T-case, I was only going to take a small amount, but nearly as soon as it started flowing it slowed to nearly a drip. I got about 1 pint, and the manual says it should hold @ 1.5 Quarts(3 pints).

The fluid is supposed to be red tranny fluid, but this looks like dirty motor oil, quite dark. I collected the fluid in a clean clear plastic jar, as I observed the bottom of the jar I started to see lots of fine sparkly bits suspended in it, and soon lots of metal dust and some slivers had settled on the bottom. It may have just been the oil they are in, but they appear to be reddish copper color, but again not sure.

I'm basically looking for the indicator that gives me the go ahead to order the T-case I've found. I'd love to dive into rebuilding the case I have, but since I've never worked on the inside of a gear box before(and don't know how long it would take me personally to complete), and since I can't afford to have this off the road for more than a day, I'll just have to do a swap and rebuild the old one later.

 

[Oregongreen]

I decided to drain the remaining fluid, and refill with fresh until I can take some more permanent action on this T-case.
While watching the fluid drain, I noticed I could see some bits of copper colored metal in the drain hole. After I fished them out, I stuck my finger further into the hole, I could feel bigger pieces of the metal on the floor of the case. Straight back I could feel a vertical smooth surface, and flat against that surface was a piece of something else smooth but broken at the edges(Edit:This was a sprocket and a tooth on a chain). I'm pretty much assuming at this point that there is some major damage inside the T-case, and I'll be ordering that used one shortly.

 

[Oregongreen]

My father says it looks like a bushing got ground up.