stikineriver

Well, my 4x4 was working on my 98. the other day i pulled the handle and heard a thump. I don't think i had the handle pulled all the way back. The 4x4 light fluttered a few times. Now the 4x4 will not engage. I tried 4 low and could feel the gears trying to mesh and did get it into 4-low, but the front end did not engage. The things i may try are...
1- pull the handle to engage and see if front drivshaft spins
2- check vacume at the actuator
questions
1- which vacume hose pulls the actuator in, to engage 4x4, the drivers or passengers side?
2- is the 4x4 light turned on by the actuator?
3- can i remove the acutuator and operate it maunally?
4- any other ideas of things to check?

Crimedog

Yes, the light is triggered by the actuator on the axle. I don't remember off hand which one pulls the collar into 4WD. However, one should have vacuum in 2WD, then when you pull the lever all the vacuum should switch to the other line. I would verify you're getting good vaccum up front first. If you aren't trace the lines back and try to find the culprit line. It could also be the switch on the Tcase.

If you are getting vacuum up front, then the fork or collar could be binding. You can pop the cover off and rig it up to manually stay locked. It's just 4 bolts on the cover and some RTV to seal it back up.

LJTyre

Any info about how one would go about
??

These vacuum leaks are getting to be a pain

sorry for the hijack

TxDiesel007

Well said

You also might wanna check the vac line connections from the T case to the steel lines that go to the front and connect to the vac actuator. Sometimes oil will plug up these lines and not cause the 4wd to work properly. This implies on my 96, not sure if the 98 is a hydroboost or not, it probably is, but if the 4wd somehow runs on vac pressure it might be worth a look.

Also teh four way switch on the top of the t case might be bad, but since ur 4x4 indicator comes on, id turn my attention to the actuator itself.. perhaps its rusted in, or has oil and water in it not causing it to work


Rick

stikineriver

What i found was the front driveline did not spin wht the t-case engaged but the front tires did. I did have vacume at the actuator. The drivers side when the t-case in 4x4 and the pass side when in 2x4. I hooked up a hose to the driver side and applied manual vacume (sucking on the hose) and found air going in the passenger side (which led me to belive the diaphram to be bad). I plugged the hole on the passenger side and got the 4x4 to stay in, but i still don'e have a light on the dash. The dealer wants $245.00 for the acutator. I wonder if i can just get the diaphram? Thanks to all for the info. John

scottsjeeprolet

You could probably get the Posi Lock cheaper than the vacuum actuator.
Just google posi lock it replaces the actuator on the front rear and makes turns it into a manual. the advantage of this being able to use low range in 2wd.

stikineriver

Hey, another friend just told me about this today, so i went to http://www.eastcoastoffroad.com/posi/ and found one. The site has good info and installation instructions.

stikineriver

Found another site for a home made one, http://home.earthlink.net/~stevenschreiber/cabledis.htm

TxDiesel007

NOt so much so

vac actuator is 70 bucks Posilock is 200, I did tho, Posilocked it and forgot it... NO troubles since then...



Rick

pitr

One more vote for the posilok. I have one now, and I had one on a YJ before this. Not only will the stupid vaccum motor never fail again, you now have the option of 2wd low. You can put the tcase in 4 low and not engage the front axle giving you 2 low. Very usefull when your trailer is burried in the mud.

-Matt