Is my shift-on-the-fly connected right?

[macdude443]

Here is how I connected the lines for shift-on-the-fly.  The front axle is engaged with the hose clamp method.  I hear pressure at the switch when I change it, but nothing happens at the t-case.  Vacuum gauge in console reads normal.  Trying to rule out the lines before I pull the actuator and check it out.

[BenM]

Try a check valve where indicated on this diagram. The plugged line needs to vent somewhere, but not all the time.

[Amc1320]

Is the switch not moving while its sitting or after you switch and drive it a bit

Mine has to move a bit before it enguages

I hooked mine up like you did, but it didn't do anything until I jacked up the front wheel and moved it a bit back and forth, then it switched over

[maximus7001]

Try a check valve where indicated on this diagram. The plugged line needs to vent somewhere, but not all the time.

Number 5, 4-WD Indicator light and vacuum switch. Is there an indicator light somewhere?

[BenM]

Number 5, 4-WD Indicator light and vacuum switch. Is there an indicator light somewhere?

Not on the Eagle, but in the same system on some Jeeps there is. I'm not sure which Jeep this is for, probably a Wagoneer.

The Axle-Transfer case systems were similar across AMC lines.

[carnuck]

The third port of the transfercase motor needs to be plugged or you can tee it to the one next to it. When the switch is flicked and vacuum is applied to one port on the tcase, the other line "breathes" back through the switch

[madmax4x4]

Try a check valve where indicated on this diagram. The plugged line needs to vent somewhere, but not all the time.

So #5 would be a check valve that just ends or vents to the air?

[IowaEagle]

That looks like an XJ setup that had an indicator light when in 4wd.  Eagles did not have that, kind of wish they had.

[carnuck]

That is Grand Wagoneer setup with NP229. The Eagle with vacuum axle http://oljeep.com/gw/vac/eagle/EagVac.pdf Grand Wagoneer same timeline. http://oljeep.com/gw/vac/84-86/selectrac_vac_layout_84_85.jpg

[Zoro]

Were you able to reuse the OEM vacuum lines or did you have to add new line somewhere? Doing the same thing on mine.

[carnuck]

I'm parsing down the excess from mine. I need 2 hoses to the tcase motor (one to engage and one to disengage) The front axle won't be vacuum anymore. A vacuum line goes to the ball from the intake, then from the ball to the dash switch. That is ALL that is needed with the front axle permanently engaged.

[Zoro]

I'm parsing down the excess from mine. I need 2 hoses to the tcase motor (one to engage and one to disengage) The front axle won't be vacuum anymore. A vacuum line goes to the ball from the intake, then from the ball to the dash switch. That is ALL that is needed with the front axle permanently engaged.

Just got underneath mine and here's what I came up with:

The RED line that goes to the side of the axle actuator is the YELLOW line that comes off the T-case

Disconnect RED line from axle actuator and YELLOW line that runs to the axle actuator from the 3 line cluster that runs down the firewall

Plug the RED line into the YELLOW line and figure out a way to deal with the extra slack in the RED line

Cap off vac exhaust from the T-case that runs to the front axle

Anyone see any reason why it wouldn't work?

[carnuck]

I'm trying to figure that one. I take the hose off that is closest to the tcase linkage and cap the hole. Then I run only 2 lines from the dash switch to the middle and far end connector on the tcase motor. Apply vacuum to the middle port on the switch.

With the front axle permanently engaged I can now shift on the fly and toss all the other vacuum hoses for the axle.

[Zoro]

Just found a REALLY simple way to hook the vacuum lines up.

YOU NEED TO HAVE THE AXLE LOCK MOD DONE TO TRY THIS

Remove the BIG rubber plug where the YELLOW and GREEN hose go into the axle actuator.

Connect those two together with a piece of vacuum hose.

That's it!

I'll post up a photo next time I get a chance.

My 4WD is now shift on the fly

[Zoro]

Just found a REALLY simple way to hook the vacuum lines up.

YOU NEED TO HAVE THE AXLE LOCK MOD DONE TO TRY THIS

Remove the BIG rubber plug where the YELLOW and GREEN hose go into the axle actuator.

Connect those two together with a piece of vacuum hose.

That's it!

I'll post up a photo next time I get a chance.

My 4WD is now shift on the fly

Took the Eagle out and romped around in the snow and the 4WD is working good. Shift on the fly works but I'm hesitant still to use it LOL.