okay.....my 4x4 does not work.....heres how it goes.....i did the engine last year and now the 4x4 does not work...so i believe its a vacuum problem. the vacuum pod is still in there. now what i need to know is which vacuum lines go where. there is a red and a light blue vacuum line with in-line check valves which come out from the underbody...which i believe are from the t-case. so which goes into the pod, or is it neither? the other port on the pod has to come from vacuum of the intake i believe....? i just ran a vacuum line from the port off the elbow for the brake booster to the pod and i tried plugging in the red vacuum line to the other port but nothing is happening. i cant find anything in my maintenance manual either so i now come to you. anyone with any pics of the hookup or any helpful info will muchly appreciated.

Jeeps... Well I had the same problem with my 4x4 not working. If you take the vacuum lines off and put finger on one of the ends of it you should feel a vacuum when you have the four wheel drive ingauged. I am not sure which vacuum lines are what but I know the main problem I had was that my shifter fork ( inside the actuator ).

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I went through two shift forks, either bent out of shape and/or cracked where it sits on the shaft thingy. I to had no problems with the vacuum but I kept on losing 4x4. It seems that even the slightest play between the shift fork and the shaft of the actuator is cause for failure. I mean little itty bitty play dude! I bought myself a steel shift fork and added more shims for less play. It seems that I have fixed the problem for now...

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This is a start I hope.

Laters

i got it all fixed up, forgot to update this post... just ended up that my vacuum wasnt hooked up properly. then i wasnt getting quite enough vacuum, so it took a while to engage, its all good now, vacuum right off the manifold. thanks for your input though

Sorry but vacuum straight off the manifold won't work, been there tried that. When you go to wide open throttle or even close to it such as in the mud or pulling a hill, your engine vacuum goes to zero and then the front axle disengages usually with a loud bang. To preventt this there is a vacuum reservoir(large plastic bottle) somewhere in the system that has a one way check in it that holds vacuum in the axle when engine vacuum is nill. You need to keep it in the system somehow or the axle can disengage under heavy acceleration.

yah, i got one of those, but how do i tie it in?

Not sure how many ports your reservior has but one should be <in> and the other <out>. To tell, plug one port and suck on the other. If it holds vacuum when you quit sucking then you were sucking on the in port. If not then the one you pluged is the in port. The in port should go to the engine manifold and the out port should go to the t-case mounted vacuum switch then onto the front diff.

Also I'm not sure about YJs but on my '89 XJ the heater controls are operated by vacuum as well. So you may have an extra set of ports on the reservior for the heater controls and cruise if you have it. If its not hooked up right then you will only get heat from the defrost vents.

mine just has the 2. ill try it and get back to you. thx clay