Jeep: Problem shifting into 4WD


Old 06-05-03, 01:43 PM
John Bruner
Visiting Guest
Posts: n/a
Question Jeep: Problem shifting into 4WD

I have a 1991 Jeep Wrangler w/ the small 4 cyl engine.

This past winter, a problem shifting into 4WD began. At first it was intermittent. Later, it was constant, but would shift into 4WD when vehicle got to 30mph. Finally, it wouldn't shift out of 2WD at all.

My son had the transfer case out at school and apparently it operated fine on the bench. His teacher concluded that it was probably a vacuum problem, but they couldn't find it. I have looked the engine over for leaks or disconnected vacuum lines and everything looks OK.

My question is: Has anyone installed a mechanical means of doing what the vacuum actuator is supposed to do... like a cable to the dash? I'm hoping there is a kit I can buy for this.
Sponsored Links
Old 06-05-03, 06:18 PM
Visiting Guest
Posts: n/a
Why? There is likely a vacuum switch or actuator that turns on the 4WD.

Call any Chrysler dealer and ask, or look in below.
Old 06-05-03, 07:23 PM
darrell McCoy
Visiting Guest
Posts: n/a
Seems some used a "Shift motor" mounted on the front differential and if I remember correctly it is vac controled. For curiousity You might check there. Probably about 2" in diameter. Would only be one hose. As Joe sez, dealer would show you what kind or where controls would be.
Old 06-06-03, 03:15 AM
WeldGod's Avatar
Join Date: Mar 2003
Location: Texas
Posts: 616
I have seen those for the NP23x, 24x, 27x, cases. I only know one guy who used one, but he really liked it, he had it on a S-10 ZR2 it made him a believer. I will do some checking and see if I can find out the one he used and if there are any others.
Old 06-06-03, 05:53 AM
Visiting Guest
Posts: n/a
Original poster: Check for any help there. I know there is a vacuum or electrically activated motor that shifts into 4WD. These get old and lazy. Sometimes they can be dismantled and cleaned to restore service (Fords come to mind with this).

If the 4WD is used infrequently, the brushes on many actuation motors gets glazed.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes