i have a 85 jeep cherokee i am redoing i am usein an 89 jeep cherokee as parts will the 89 jeeps frount end work in the 85 jeep far as 4x4 wise the 85 jeep has a shif motor on it the 89 dose not so if i take the 89 frount end and put it in the 85 doi still need the shift motor

 

It will work, the shift motor or "Central Axle Disconnect" system was an attempt to replace the hub lockouts for lazy americans that cant get out and flip the switch. They stop making these in 91. I had a CAD axle in my 95 for awhile and simply just jammed it locked.

I'm not 100% but those 80's tcase had vacuum running to them and then to the axle. idk how it will affect the tcase removing the vacuum.

 

I have a 90 with the vacuum disconect... I just took the 2 piece axle and replaced it with a 1 piece axle pulling the vacuum lines... The only downside was i list my 4x4 light, its possible that I could remedy that but its not an issue to me. I know when my tcase says 4x4 its in 4x4 and etc.

 

Yes you can do that and I almost did that to mine but my pinion bearing was bad so i tossed it. The old CAD axles have a stronger housing than 91+ but smaller ujoints.