4wheel drive not working

[Adamstrator]

Found out today that my four wheel drive isn't working. I checked all the vacuum hoses hooking into the front diff and they were all intact, if there is a leak somewhere how can I test it to find it? Is there anything else
besides a vacuum leak that could be causing this? When I move the switch to the 4wd selection, there is an air releasing noise. I know it always made that noise when I would switch back to 2wd but I dont remember ever hearing it in 4wd, is that normal? I have an 83 Wag w/ the 229 btw.



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Adam Zeimet
IFSJA Webmaster
83 Wagoneer Limitd

[jeepbob]

you could have a cracked line or a bad switch. Test the vac motor with a hand held vac pump (The good ol Might Vac tester), you can test the whole system with the tester.

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65 wag. 360/edelbrock rb4/t400/20 t-case/4:10 d27/d44 tracloc/onboard air/onboard 110v power(no inverter)/1999 Lincoln t.c.leather buckets/taurus ctr console/winch/33x12.50/tunes/water proof door pads
soon to have new motor/d44frt/d60r(4:10)welded diff/custom bumpers
see ya in da mud

[78Chief]

Mine makes the same noise when I switch it back to 2wd but not whe I put it in 4wd. Wish I had some more knowledge and could help you out.

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78 Chief
401 (The Beast)
33" BFG a/t
Hey It's Big and Green!

[ClarkGriswald]

Mine makes the noise both ways... and ive been fighting it since ive had it.. block the tires, and put the tranny in neutral, and start the engine so you have vac power.. and get under there with a big pair of square jaw vice grips and move the smaller mode lever manually.. it may just be gettin gummed up and stuck like they have a tendancy to do.. if you have a hand vac pump, you can leave the motor off, and just hook it to either side of the vac motor and pump it up .. i used this method to initially free mine up.. i just hooked to hoses up to the vac motor, and had em hanging down. then i would switch my little hand pump from one to the other.. this way the little vac motor was assiting me in moving the lever back and forth.. (this will also let you see if the vac motor is good as it should hold the vac you apply to it).. you can use it on the front axle too to check it out..

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88 Grand Wagoneer
D44's front\rear
Warn 20990 Lockouts
AMC 360
TF 727
NP 229--Soon to be replaced by an NP208 that currently inhabits my kitchen.

"I came, I saw, I typed some stuff!"

[Coley]

I would say something's gummed up. If it makes the "pssst" noise and stops, then I think it's holding vacuum. When my vac line was broken on the front diff., it made a continuous "psst" sound at the switch, since air was still rushing through it.

Mine makes the noise going from 2wd to 4wd and vice/versa.

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Daddy's Ice Cream Truck (3 yr old daugter named it)
360 727 NP229
Totally stock
"You're obsessed with that thing!"

[arter]

Have to agree with checking the vacuum motor. Replaced it when I bought the '86 a few years ago. About $150 at the dealership then. Hayden manual has decent section on checking the vacuum operation. Good luck!

Art

[Brazzy]

How do you know it's not working? if it will go into 4x4low after switching to 4x4 then it is going to point at the viscous coupling inside the unit and thats costly!!!

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Brazzy
Formerly abused 87 G.W. 170k stock
TOW,PKG,727,229,360
The Chariot

[Adamstrator]

It wont shift into 4lo, thats how I figured out it wasn't working.

[JEEPRZ]

If it wont go into low, then the problem is at the t-case side of the vacuum harness, or the t-case solenoid. Id pull the vac lines off, to see if you are getting vacuum down their first. I re-routed my lines, so only the t-case solenoid is controlled by the switch. The axle stays locked all the time.


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Dave
83 GW
360/727/229
tow rig for 85 CJ
3"lift, 31s, 3.31s, edlebrock intake (TBI in the works), cam, custom DIY exh, rebuilt trans shift kit and factory aux cooler,modified 229 (no viscous coupling, *improved* vacuum system), lotsa squeaks, leaks, and rattles

[Adamstrator]

Well, I dont know what I did, but I fixed it... I think. Everything was getting vacuum, but the linkage thing (between the tcase and the vacuum motor) wasn't moving hardly at all... so I jiggled it, then it all started working again <shrug>.

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Adam Zeimet
IFSJA Webmaster
83 Wagoneer Limitd

[andy d]

yup, frozen up due to lackause. you hafta do more wheelin.

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'88 gwag,pure stock

[Adamstrator]

That would explain it... until this week, I hadn't even driven the Jeep at all for about a month, and I hadn't wheeled in about 2. Hope thats all it was.

[This message has been edited by Adamstrator (edited February 12, 2001).]

[wagdriver]

If you wern't working so hard keeping us on the site happy your Jeep would be working better on the trail. Good job Adamstrator!

wagdriver http://www.ifsja.org/ubb/smile.gif


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wagdriver
88 Grand Wagoneer
135k and still going
K&N everything else stock
95 Dodge Ram 2500 360 stone stock