vacuum lines to the E-drive switch

[roadgrime]

so i am still piecing the 200.00 jeep back together though i have been driving it for 2 days now as told by all my posts here.

anyway the glove box and e-drive switch are missing. and the three vacuum lines are plugged with screwes. can some one tell me / reasure me the e drive is disengaged?

when i back up it feels like i have a locker in it ie back up and turn the wheels kinda bind a bit.

[jaredn79]

Sounds like your E-drive is engaged or partially engaged. You can get a vacuum coupler and manually couple the vacuum resevoir with one of the E-drive lines (to engage or disengage). There is a light in the instrument cluster (I believe its the top-right-most indicator, the bulb may be blown or the E-drive indicator switch on the transfer case isnt hooked up/wire broken/etc. Dont drive it anymore until you get this resolved or you could burn up your transfer case.

[roadgrime]

is there a way to test for e drive engagement? none of my dash light work except turn signals/hazards

also how would i hook up the three lines until i get a switch ?

[ August 19, 2003, 01:11 PM: Message edited by: roadgrime ]

[jaredn79]

Get underneath you rig, run a vacuum line from the "RELEASE" side of E-drive control diaphragm to a vacuum source on the motor. Plug the "APPLY" side of the control diaphragm. You should just go ahead and pull out the instrument cluster (you dont have to even pull it all the way out) pull the bulb thats on the top-right-most position - test if its good or replace it. Then check the wire that plugs into the transfer case, above the diaphragm, on the top plate (the wire should be orange - mine was cut in half and dangling from the transmission)

http://209.238.200.129/gw/vac/axle/qt_tc_vacuum_diagram.jpg

This is what I would do step by step:

1)run a rubber vacuum line from a vacuum reservoir to one of the steel lines.

2)Get under the vehicle and disconnect both rubber vacuum lines from the E-drive diaphragm.

3)start the vehicle

4)get under the vehicle and listen/feel for vacuum on the lines. If you dont have vacuum check reservoir, then steel lines (replace if neccessary)

5)If you do have vacuum plug that sucker into the release side of the diaphragm (the one closest to the rear of the vehicle)

Hope this helps. I replaced my steel vacuum lines that run from the engine compartment down to the transfer case with steel brake lines (cutting off the ends).

[roadgrime]

good info jared. where did the image come from? thats the kind of diagrams i am looking for. and chiltons aint cutting it.
chiltons dont even show emergency drive control.

also is it possible the diaphram is bad?

short of the light being on since after checking bulbs and voltage my console is screwed up and none of the lights work. is there another way to know if it is in e drive?

[jaredn79]

It's on Tom Collin's website:
http://209.238.200.129/gw/elec/GW_wiring.html

Another good site:
http://www.slidingdelta.com/fsj/wagoneer.html

I think the indicator light is the only way to be for certain. Did you hook up and test the vacuum going to the release side of the diaphragm? If you do have it hooked up to release, drive (slowly) in reverse in a large "S" shape. Then slowly drive forward. That may help it engage, also check the fluid levels in the case. Do you have the optional reduction unit? (the lever is under the driver seat, I think).

[jaredn79]

I meant "that might help it DISengage" sorry.

[roadgrime]

yes i hooked up the vacume line. although i am not positive there is enoigh vacuume. i do have the reduction unit at the back of the transfer case as well.
but i am still hearing the rear end bind a bit...

[jaredn79]

Make sure you reduction unit is shifted into high gear. Is the "apply" side of the diaphragm capped? Try this: Pull foward, slow to 5 mph, put your transmission in neutral, REV up the engine to increase vacuum. Try the same thing in reverse. Even try doing the "S" shape in reverse (in neutral if possible). If you can do this on a loose surface that would be best. If you could find any vacuum switch (ie. hook up your heater vacuum switch /in the instrument cluster/ to the E-drive) so you can "Apply" and "Release" until you feel it disengage.

[Crazy_Jeepman]

reving up the engine DECREASES VAC.

[jaredn79]

Oops.

[Green Giant]

Obviously never driven a car with vacuum wipers. :rolleyes:

[jaredn79]

Huh? Is there really such a thing?

[bvibert]

There was... back in the olden days before they new about electricity!! :D tongue.gif ;)

Hehehe.. just kidding old guys smile.gif

[roadgrime]

well my military vehicles had vacuum whipers .. they worked like crap.

back to the task at hand....
the apply side is not capped. I cant tell via the light since my guage console is shorted out. vacuume is flowing to the release side though it seems like not very much.

can you apply and release them while moving or must you be in nuetral IE right now i have a fish tank switch so i could apply vacuum to either the apply or release side and if i can do it on the move "?maybe?" i could tell if its engauged or disenguaged.

[jaredn79]

Im not sure if it has to be capped, but in essence the vacuum switch does "cap" the line when you turn the knob. You SHOULD do it while moving (rolling) in neutral. My E-Drive got stuck once, all I did to remedy it was: Put the switch to the release side, drove it in reverse in the "S" pattern (hard left, then hard right) for at least 15 feet (like the book said), it did not disengage until I drove it forward again. It was also scary because the rear end was sort of hopping.

[roadgrime]

well thats kinda what mine feels like.. not as bad as having a full spool or a hardcore locker... more like my 89 xj does when i have it in 4x4 low on pavement
and yes i am pretty sure i am not in low since i can do 80 in 3rd gear (auto)

[jaredn79]

Maybe it IS lack of vacuum, or the diaphragm may be clogged or bad. My experience doesnt lead me that far. So hopefully someone else may chime in.

[Langdon]

Roadgrime:

You can apply enough vacum with your mouth to move the diaphragm, and you can hear it move. Just get a length of hose and try both nipples to figure out where it is. If nothing happens move the truck a bit to get the gears lined up and try again.

I think you'd know if it was in Edrive from the obvious wheel binding. If you have never had a Qtrac before, ones with tight cones have mild bind/release (growling from the case) in regular mode, it's the nature of the beast. :cool:

[Spudz]

More specifically, revving decreases MANIFOLD vac, it increases PORTED vac. But if the accessory vac canister is hooked up to ported vac then you got some other problems. smile.gif

Those diagrams, besides being from that web site, are from the "TSM" (technical service manual) published by Jeep. You can find them on eBay quite often, very nice to have compared to Haynes/Chiltons/etc as it does have these extensive diagrams.

If you have a ohmmeter you could hook it up to the e-drive pin on the switch at the case, and the other lead to ground somewhere, and it should show a connection (0 ohms) if e-drive is engaged (which would make the dash lamp light up if it wasn't all freaked out). But this would seem trivial as it seems pretty obvious that it is in e-drive.

Yes those actuators go bad, it's a rubber diaphragm based deal and like any rubber they crack and leak after so many years. They are hard to find I think, and also expensive, you may want to check in the "for sale" section or post in "wanted" to find a working used one for cheap that will likely work fine for quite a while. And while you're at it if they have a spare actuator you can likely get the switch too even if there's no glovebox to mount it in yet (or, get the glovebox too).

If you have a vacuum gauge, the actuator operates on 15 inches of vacuum. Hook up to the vacuum canister directly with the gauge and see if you're getting near 15 at idle, if not check ALL vacuum hoses for leaks or just plain replace them all anyhow to be sure (sometimes visually OK hoses can still leak). An alternative if there's enough length left in the old hoses is to cut the old ends off with a razor (so you get a nice unmangled slice) and reseat them on their nipples in the various places, after a while stretched over the nipples the hoses will not be completely airtight, 'refreshing' the ends often makes for good connections without replacing the whole run and doesn't take a trip to the store. Anyway, check vac levels at various points thru the system and see if there's a lack once it gets near the actuator on the case and debug in between as necessary. You can also suck on the vacuum gauge and see how much that is, to do the suck test directly to the actuator just so you know you're sucking hard enough. In any case if you do the suck test and it doesn't hold pressure (like there's some leak down and you have to add more pressure) then the diaphragm is shot and leaking. If there's no leaking there, then perhaps it's jammed somehow and the 'gentle' 15 inches of vac isn't strong enough to move it internally (or the nipple is clogged up somehow). This binding/jamming is what the whole backing around in reverse swerving process is supposed to relieve or loosen. You should be able to get the retaining clips off the actuator and yank the whole thing outward to physically try disengaging, as the shaft moves outward for disengage and inward to engage (thus, it's stuck inward and pulling the whole thing while it's still connected inside would effectively be tugging on the same thing it should be if it were working, just a bit more forcefully).

Also in the mean time if you're reasonably sure it's going to stay jammed in e-drive, you could take off the front driveshaft and just tool around in 2WD safely and with less/no damage to anything (would eliminate the binding by eliminating 4WD). That is if you need to be able to drive it and you can't get it figured out or shifted out of e-drive by some method.