96 - Sounds like 4wd engagement spline is not staying engaged

Just joined the forum as my 96 Cherokee Sport is getting older and I'd like to keep it running great. Here in MT we got a good dumping of snow last night. Started Jeep till it was good and warm, put it in 4wd and pulled around to front of house from back with no issues. It sat for maybe an hour and then restarted it to take my son across town to his friends house. As soon as I engaged the clutch I hear a popping and snapping sound coming from approx the lever and transferase area.. I'm a machinist and build custom rifles for a living.. always been pretty mechanicaly adept. I take it out of 4wd, pull slightly forward, reengage 4wd and go in reverse to in my logic help spline fully engage and then pull out again. Seems to hold for the moment. Go across street and gun it a bit to drift the next corner and boom it starts popping and snapping sound again! Ugg, I'm thinking oh shit this sounds bad.
Ok.. Doing some research and saw a comment made that there is a vacuum engagement type design on the lever system that engages the 4wd? Can anyone on here point me in the right direction? A factory service manual drawing? Or have any direct experience with this very Issue? Thanks in advance

 

No vacuum on the 96, earlier models pre-91ish had a vacuum diaphragm on the front axle.
T-case engagement is mechanical. Get underneath and make sure there aren't any missing bushings that would keep it from engaging fully. Do you have a lift with a transfer case drop? It may also just need some adjustment.

 

Thanks Prerunner,
I was wondering about the vacuum operation as I never noticed a diaphragm before. No lift or drop that I'm aware of, completely box stock, zero mods. I'll cross my fingers that it's only an adjustment thing as it's nearing 300k Miles (297000 to be exact)

 

Ok, warmer weather here today got underneath to check thinks out. All lever linkage points feel tight, no appreciable slop in the plastic pivot rod bushings. So this leaves me with the scary thought of something coming loose inside the transfer case? I also purchased an online factory service manual that I downloaded. However my 2013 Mac doesn't seem to be compatible with the latest version of Adobe reader.. Grumble
I can browse it manually but I have yet to find anything in the Index that points me to the 4wd lever function/maintenance.

 

hmm.. that is unfortunate. My next thought would be that the chain and/or gears are worn and it is jumping teeth but it's hard to tell without hearing it for myself.
Good luck, please update with whatever it ends up being as I would like to know.

 

I certainly hope that the chain is not hopping the sprockets.. That would suck! I did finally hunt down the transfer case diagrams and the linkage drawings. Since the lever adjustment rod (little cross bolt that locks the adjustment in place) is a bit rusty and shows no signs of slipping the only way it could be out of adjustment is motor mounts/tranny mount old and worn affecting the relationship? If the relationship of lever is now allowing only a partial engagement of the 4wd high gear could that be a possible cause? Might be worth pulling the linkage, cleaning it and then reinstalling it according to the manual and see if that fixes it?
Even though it's box stock I have used her hard for the last 100K miles. Lots of 4wd use on muddy, rocky and dusty roads. Lots of off road climbing and towing trailers, dragging shit etc. Maybe I have actually stretched the chain enough to hop. I will update when I figure it out.. could be awhile as its my daily driver and this might just require the purchase of another vehicle. There is lot's of things getting worn out on her so a complete vehicle rebuild may be in order..
On that note is there a turbo kit that can be purchased for this model? Always thought the design of the straight 6 left plenty of room under the hood to retrofit one.