cagedxj707

Ok so I've got an 88 xj, unsure on the lift brand, its a 5inch long arm though. Anyway, my 4x4 isn't engaging? Its got stock axles d30 front. Vacume lines maybe?? They look pretty old and dirty.

RickBross

Could be. Mine went out once, it was the tranny.... good luck.

cagedxj707

Everythings working how it should and I can feel the t case shift into 4x but the fronts just not engaging at all.

RickBross

What engine what transmission?

cruiser54

Here's the simplest and easiest way to get around the vacuum crap.

https://www.cherokeeforum.com/f51/fr...ss-91-a-38629/

cagedxj707

Its a 4.0 five speed, its an 88 I'm not sure on the exact specs lol but its stock motor and tranny and t case.

cruiser54

All that vacuum harness deteriorates over time. Especially because when you remove your oil filter, the oil flows down on to it's rubber hoses.

lookin2wheel

This is a good write up. I did it to my '91 and there are no driveability issues and I have 4WD again! I do encourage you to do this.

cagedxj707

I'm not really looking to by pass them and run mine with the front turning all the time. I'm looking to fix it, could I just clean the lines and maybe put some sealer on em and plug em back in?

cruiser54

Sure you could. You could trace everything out, replace lines, try to get the plug to stay stuck on the shift motor at teh front axle etc etc.

But why?
The Cherokees with the NP242 transfer case had no axle disconnect and in 1991 Chrysler eliminated it on the NP231 equiped Cherokees. There is no mileage benefit in keeping the CAD. If there were, the 242 t-case Jeeps would have had lower EPA gas mileage estimates. They didn't. If eliminating the CAD would have cost Chrysler a loss in CAFE, they wouldn't have done it either.

The other risk in keeping the CAD vacuum system, which is prone to failure with bent shift forks, vacuum plug getting pulled from the shifr motor, vacuum lines rotting etc, is that the only time it's gonna fail on you is when you really need it.

cagedxj707

**** it, guess ill just bypass it then, I cleaned em all up today and it still didn't work :/

cruiser54

That setup gave us fits at the dealership when the Jeeps were new. I can't see how they improved with age. Good decision.