straightsixjeep

Who here has experience with using a RE hack & tap with a front xj driveshaft with the spicer adpater? Im thinking about this route instead of a full sye kit and custom ds.

salad

It functions as a vacuum reservoir for a few systems: The heater directionality doors, cruise control, and on some years the heater blend door are all vacuum operated. (Dunno why, servos would make more sense but I'm sort of glad that Chrysler didn't have the chance to screw up more wiring.) The idea of a vacuum reservoir is that sudden drops in engine RPM won't effect those systems - eg. cruise will remain on the throttle when the transmission up-shifts and the heater will stay on bi-lev instead of returning to the default defrost position.

If it's gone and the hose to the manifold isn't plugged it's actually a vacuum leak and will cause the usual problems.

onlyinajeep726

I used the Dirtbound Offroad kit (which is basically just the IRO kit). I used a front DS from an '88 XJ automatic. Works fine. My strong advice though, DRILL SLOWLY when you get to that part and use a tapping fluid to keep the bit cooled. Also, make sure it's as close to center as you possibly can.

salad

It's the Beetlejuice drive shaft! lol

mitchlikesbikes

so then this would probably explain why my cruise light will turn on, but i can't set cruise? and what you're saying is if it is missing, as long as the hose is plugged i'd still have the problems i do, but the typical problems like wonky idle wouldn't arise?

bhennessee1

Typically the idle wont be thrown off. The vacuum line to the ball is tiny. It's just not big enough of a leak if the ball is missing you can plug the line, and it will work. Mine had been plugged since I bought it, and my cruise and heater controls work fine. Just trace the line from the cruise back to the intake, make sure there isn't a leak, the hose for the ball runs next to the battery and out below the header panel into the bumper.

onlyinajeep726

Hahaha, yea... I had to have some fun with it lol.

XJAcosta

Ok I went through 30" of water the other day and then my friend said "hey you better change out those differentials, unless you moved your diff vents higher..." Should I be worried about something or what? I have a 93XJ stock rear 8.25 axle and stock front Dana 30.

Lowrange2

He's saying your axles are most likely full off water. He's probably right.

Pull the covers and change the fluid. Done.

99superjeep01

Yup. As for the vents/breather, the front should be run up near the cowl but the rear end isn't as high. Make sure they're connected and you're good. Though if your seals aren't any good those breathers aren't very useful.

straightsixjeep

Thanks for the info and the pic. I just looked it up and found it. Other than the kit, did you only need an auto xj front driveshaft? Did you have to open up the t-case? Im not sure if an actual sye kit uses a yoke that will allow me to run a front driveshaft so Im leaning towards this kit.

bhennessee1

A full sye kit will allow you to use a front drive shaft, all of the drive shaft u joints on a cherokee are the same size.

straightsixjeep

Thanks for the info. Most people say they are able to use a cherokee front driveshaft with their hack n tap however thats with the aw4 trans. Final question, can I use a xj front driveshaft for the iron rock offroad hack n tap if I have the ax15?

bhennessee1

Maybe, youlle probably need a a zj shaf or something.

my89xj

Anyone have a sticky for adjusting the tps?