Help with 4 wheel drive problem
 

We have a 89 Jeep Cherokee and we can't get the four wheel drive to work. It has a new front end and activator and all vacuums are hooked up. Both drive shafts turn. Does anyone have any suggestions?

is the shift fork installed properly on the collar inside the actuator?

What do you mean by both drive shafts turn? Do you mean the front drive shaft turns when driving when you shift into 4WD? If that is thew case then your TC is working fine. So, your front vacuum disco still have an issue. You may have a new disco and have your vacuum lines hooked up at the axle but, you could still have a vacuum leak somewhere and not be getting the vacuum to the disco required to move the fork over and engage your front passenger side wheel. Trace the vacuum lines starting at the axle disco and work your way back to the TC. I bet you find a leak or disconnected line somewhere causing your problem.