1989cherokee

I was wheeling a little bit today and i was climbing a steep muddy hill in 4low and right as i was about to get to the top I heard clicking from the front end and the front wheels stopped spinning and my rear wheels just spun out. The 4 wheel drive would not work it just made a clicking noise in the front end. i worked my way back down in 2 wheel drive and came to a point where I needed to use 4 wheel drive again or i would not make it out. It went right back in and worked fine and i made it out.
Can my 4 wheel drive be going bad?
Is it ujoints?
any suggestions?

winston427

It is most likely the vaccum disconnect motor on the front axle. They are notorious for failure as they age.

dangerousdavid

there is a kit somewhere to eliminate that vaccuum line on the front axle...i dont know where to find it but there is a thread on here somewhere about it

1989cherokee

Im not real familiar with how the vacuum lines work. does the vacuum hold it in 4wd the whole time it is in. Or is it only used while changing it into 4wd?

winston427

The vaccum holds it 4wd. That is why they fail so often. Water, dirt, and debris get inside and cause the diaphram to deteriorate and rupture, resulting in a loss of vaccum.

1989cherokee

thanks man are vaccum disconnect motors very expensive/ hard to find?

jd4x426

i wouldnt bother with a new motor iw ould just swap in 1 piece shaft and be done with it theyre also stronger then the 2 piece shafts

1989cherokee

Would this make it so it is engaged in 4wd all the time or will i still be able to put it in and out of 4wd. What year xj's have the 1 peice shaft?

winston427

92 and up has the one piece passenfer side shaft. Try to find shafts from a 95 up, they have the larger stronger u-joints. If you find the 95 up shafts go ahead and replace both side sides for the u-joint upgrade.

Having the one piece shaft does not lock it in 4wd all the time, it only eliminates the problematic shift motor. You are only in 4wd when you engage the transfer case to 4wd.

jd4x426

your axles will be spinning all the time but you will only be in 4wheel drive when you put your transfer case in 4wheel drive

1989cherokee

So is it ok to have the axles spinning all of the time? are the 95+ cherokees like that?
From what i understand there is a kit that changes the vacuum out to a cable. does anybody have any links to a kit?

offroadohio

Some 90-91's also had 1 piece BIG JOINT shafts they are few and far between but they are out there.

Could also go to a junk yard and pull 4 or 5 CAD things and carry them as spares.

1989cherokee

Has anybody had any experience with the posi-loc to replace the vacuum? OR the home made posi-loc? [Link]http://www.jeepforum.com/forum/showthread.php?t=595515[Link]

OverlandZJ

OK, lets back up here a tad. Do you in fact have a CAD front axle? Not all 89's had it. A CAD axle would have the vac disconnect unit as in this thread. https://www.cherokeeforum.com/f2/does-front-drive-shaft-always-turn-16188/

Most CAD issues turn out to be vacuum leaks as they age and the lines dry/crack.

You could do the Posi-Lock conversion, but swapping in a non CAD axle with matching gear ratio could be cheaper in the long run.

hubbazoot

Here's some info for you on vacuum disconnects:
http://www.cherokeetalk.com/forum/f2...sconnect-1102/