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transfer case vacuum hose??

IRPancake

NAXJA Forum User
Location
Oviedo, Fl
I know I know, another thread. I've spent the past 2-3 hours looking for info on this but cant find any. I have an 88 pioneer that the 4wd wont disengage. I ran into several places that said look on the front axle for the disconnect, but nothings there. While looking I found a hose that comes off the drivers side on the transfer case. It kind of loops around and it has a metal section with a bracket on it, but it was just laying on the passengers side of the transmission. Any clue as to what it is, or if its my cause for the 4wd not disengaging??

Thanks in advance!
 
If the hose you found is rubber as opposed to nylon tube, it's probably the transfer case breather.
 
thats the where it starts
mystery001.jpg

and thats where it ends
mystery003.jpg
 
Whatever that is it isn't the vacuum hoses. If you have a vacuum disconnect, the transfer case will have, on the driver's side, a vacuum switch with a cluster of small plastic vacuum lines terminating in a rubber plug which attaches to the switch. You should be able to trace the lines forward, to the passenger side of the front axle housing, where there will be a vacuum motor. On the passenger side of the inner fender will be a vacuum operated switch which controls the 4WD light. If none of these are present, you don't have the vacuum disco system.

Of course if you don't know the history of your vehicle something might have been changed before you got it. An 88 with a 231 should have TC shift positions of 2-hi, 4-hi, N and 4 low, and a vacuum disconnect setup. If it has positions for full time and part time, it is not a 231 and it will not have any disconnect on the axle.

If 4WD is engaging consistently but not disengaging, check your tire inflation and wear. Uneven diameters front to back will cause this.
 
What Matt said - but if it won't disengage at all, I'd double check the transfer case shift linkage adjustment, and that it actually pulls the lever out of engagement.
 
That hose is the transfer case breather--you're missing the section that runs up the firewall. You should add more hose, and route the end up high to avoid water getting in there.
Can you move the transfer case selector through each selection? Or, is it hung up in 4-high?
 
It moves through ever position just fine, but I'm not sure if they're actually switching or not (first 4wd I've owned). When it wouldn't disconnect, I would floor the gas for a sec, slam on the brakes, and repeat and it would knock it loose out of 4wd somehow. I dont' have anything on the front axle so I guess its not a 231. I'm pretty sure I checked the linkage when I first tried out the 4wd but it was physically moving to 2wd position, it just wouldn't disconnect.
 
It moves through ever position just fine, but I'm not sure if they're actually switching or not (first 4wd I've owned). When it wouldn't disconnect, I would floor the gas for a sec, slam on the brakes, and repeat and it would knock it loose out of 4wd somehow. I dont' have anything on the front axle so I guess its not a 231. I'm pretty sure I checked the linkage when I first tried out the 4wd but it was physically moving to 2wd position, it just wouldn't disconnect.

If the driveline is a bit bound up, it usually works best to stop and reverse if you have the opportunity. If you have to do it while moving, try putting the transmission in neutral before hitting the brake.

If you felt the difference when it popped out of 4WD, then you at least know that the 4WD was working, and the linkage is good.

It is still possible to have a 231 ("command-trac") and no disconnect, if someone before you swapped in a post-91 axle, or the axle from a selec-trac model. If they did that, it would disable the 4WD light, which operates from vacuum, unless the switch in the transfer case was replaced. Does your 4WD light work? If so, what kind of switch is on the TC?

If you really do have a command trac 88 with a 231 transfer case but no vacuum disconnect on the axle, you should do some further investigation if possible to see whether the axle is contemporary, because later axles used different brakes, and it could be very frustrating trying to buy brake parts without knowing what vintage axle you have.

If possible, take a wheel off and look at the brake calipers. Your vintage of axle should have a separate caliper bracket bolted to the knuckle. Later ones have the caliper bracket and slide integral with the knuckle. They use different calipers and different pads.
 
I took her out tonight with some friends to the middle of nowhere tonight to some dirt roads to test out the 4wd. I guess I was doing something wrong, or just fiddling with hoses did it, but as long as I forcefully (it went in smooth, just needed to give it some oomph), it would go in and out of 4wd perfect. Just to make sure we would do stop-floor it tests, its kind of cool how you can floor it and not even begin to spin the tires and take off.
 
That hose is the transfer case breather--you're missing the section that runs up the firewall. You should add more hose, and route the end up high to avoid water getting in there.
Can you move the transfer case selector through each selection? Or, is it hung up in 4-high?

I don't think there is another section. As I recall that just got bolted up somewhere near the top of the bell housing. I would add some extra line and run it up the firewall a bit though.
 
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