CAD fix (Cheap Posi-Loc System)

Has anybody ever found a vacuum control valve/switch that can be used in replacement of the valve inside the transfer case?

Here is the background of this question. My '86 now has a transplanted engine, transmission, and transfer case from a '95 cherokee. The '86 has the vacuum disconnect front axle and the '95 did away with this "feature" so there is no vacuum control on the new transfer case. Right now I have slid the fork over to the other side of the C-clip so I have 4wd(thanks girsmj86). Eventually I want to either put in a locker or maybe just weld the front differential; but if I do this I would want to have that central axle disconnect back. If my understanding of this whole system is correct, I just need to find a control valve of some kind that will change the direction off vacuum just like the valve inside the transfer case.

What do you guys think? Have any of you done this? Any ideas?

I know I can go out and spend $200 to get the posiloc cable activated thing but I was just trying to do it a little cheaper.

You can use a CommandTrak 2 position vac switch from an early XJ with the 228/229 transfer case, which is what I'm going to use eventually if I install a front locker. Give me a minute, I've got some pics of it I can post (just have to find them)....

Jeff

edit: they are on my work PC....I'll post them tomorrow morning (sorry)

You can use the dash-mounted vacuum switch from a mid-80s vintage Grand Wagoneer. They used a vacuum switch to go from AWB to locked 4WD.

Oops, I meant Selectrac :oops: . Here's the switch....it fits in the center console in front of the shifter, where that dished-out "change holder" piece is. Shot of the backside shows the vac connections, center is main vac in, and the opposite sides get the vac signal switched to them from the lever. Just run two vac lines from them to the CAD motor and you're good to go (run the vent line somewhere too). I might just go ahead and plumb mine up this weekend when I swap axles.

HTH,

Jeff

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Thanks Jeff,

You don't have an extra one do you? (wishful thinking)

Anyone know where I can find one?

Landon

the other option is a cable system.

http://home.earthlink.net/~stevenschreiber/cabledis.htm

I pulled that one from the junkyard for a couple bucks (like the majority of the junk bolted onto my MJ :D ). If I see another one down there, I can grab it for ya if you can't find one (?)

Jeff

If you don't want to worry about the CAD functioning properly, it's easy to eliminate:

1. Remove the housing/fork.

2. Pull the c-clip off the rod on the side of the fork closest to the diff.

3. Slide the rod towards the pass side & fork toward the diff side.

4. Replace c-clip in old location on rod (which is now on opposite side of fork)

5. Gently roll jeep forward to engage collar on both shafts.

6. Replace fork on collar.

If you don't have a locker in your D30, this is what I'd do. It only takes about 10 minutes.

You can also always switch it back later if you fix the vacuum issue or get a locker.

Right now I have slid the fork over to the other side of the C-clip so I have 4wd(thanks girsmj86)

Sounds like he already did that.

mjeff87, bout what year did that come out of? It is exactly what I was looking for. I tried to do it with the EGR solinoid but it didn't work.

just a heads up.

if you guy plan on running a front locker with your CAD front axle you might run into some problems if not done properly. first off the vacuum disconnect will have to always be engaged when in 2 wheel drive. the reason for this is because if you do otherwise one side of locker will spin constantly while you drive, meaning it will eventually wear the teeth off of one side of the locker. you could still put a vacuum switch on it if you want to disengage the front end to help you turn while your in four wheel drive. i leave mine engaged all the time with a front locker and never have any problems on the street as long as the jeep is in two wheel drive. even on the trail turning isnt to bad, but i did install a tera two-low kit so i have 2wd low range to take the load off of the locker so i can make tighter turns on the trail.

Right now I have slid the fork over to the other side of the C-clip so I have 4wd(thanks girsmj86)

Sounds like he already did that.

 

mjeff87, bout what year did that come out of? It is exactly what I was looking for. I tried to do it with the EGR solinoid but it didn't work.

I had it in an 86 Grand Wagoneer I had, and I have seen the same style of switch in an 84 XJ.

jeff, there is 1 flaw in the system...you need 2 hoses running from this switch to the actuator. then you need 1 hose running from a vacuum source on the engine (vacuum canisters...inside right fender on 2.8/early 2.5 and behind front right bumper on 4.0 and later 2.5). without a source for vacuum, there will be no actuation.

or when you mentioned vent line, did you mean run one from the acuator on up? if so I'm still fairly certain it wouldn't work...it's like hydraulics...to move it 1 way, fluid (air) is pumped in 1 direction. to move it the other way, air is moved in from the other direction. to do that a vacuum would have to be applied to either actuator input and they would alternate serving as a vent or vacuum.

I believe i am correct in my thinking...anyone have input on that? i have one of these switches in my spare console and i like the idea of using it....

Pat

Yeah, there are three vac connections on the back of it. The center one is main vac in, and the other two are seperate circuits, which get plumbed to either side of the actuator. The CAD has a seperate vent line already built into it, so that the actuator can move both directions.

I'm just going to pick up a vac signal from the line running to the vac resivoir and run it to the center of the switch, then run two seperate lines from the outer ports to the CAD. I'll take some pics tomorrow when I get it rigged up.

Jeff

Does anyone know where i can order one of these. I think i will go Spool in my D30 and use this to control it. What do you think oh and here is the layout of how to run it. http://oljeep.com/edge_qt.html

Cole

mjeff87, did you ever get that done? how does it work? i'm thinking of eliminating my vacuum from the tranny as I have a center console with one of these switches and the new tranny doesn't have vacuum anyways....

No, I didn't get it in last weekend....Sunday ran long and I ran out of time. If the weather cooperates this weekend, I'm going to try to get it in.

I'm also hitting the junkyards, and I'll grab any of thoses vac switchs I can if there's any there for you guys.

Jeff

I just saw a t-case type vacuum switch hanging on a rack at the local Kragen Auto Parts. It had 3 line in / out ports and it was under 10 bucks. It looked like it would be actuated by something bumping into a spring loaded ball bearing poking out of 1/4" pipe threads on the rear. I was surprised to see it next to the driveshaft u-bolts.

It shouldn't be that hard to find something that would work.

yea i'm just using the selec-trac switch, there's no hole for the vacuum switch on the new transmission that i'm looking at...an ax15 from a dodge dakota.

I just want one so i can use a Mini spool or full spool and then use the Vac switch to regulate when I want it to be both. I have a lockrite but i am thinking of selling it cause i like the idea of a spool better. I tried searching on the internet for one that might work but had no luck. And MJeff87 if you get one PM me and i can paypal you for it. And that goes for anyone else with one. I hope that link helps with the hook up for those who didnt qhite understand Mjeffs idea. Thanks

Cole

linky no workie....... :cry:

Jeff

edit: woo-hoo! I broke the 1000 post barrier, and didn't even notice it...

It should now but who knows they do crazy stuff over here to the comps. I can't even see any Pics if they are hosted by a banned site Like picturetrail or photobucket. :cry:

Cole

i hooked up my selec-trac switch to a vacuum source today. then hooked it to my spare CAD to see how it worked. it's ingenious! worked like a charm and once i figured out which line should be 2wd and which should be 4wd, it worked great!

so i'll be installing that permanently onto my manche. it will give me an extra advantage and also the ability to handle corners without sacraficing all of my front end and no wheel hop :D ...i hope.

Thanks Jeff,

 

You don't have an extra one do you? (wishful thinking)

 

Anyone know where I can find one?

 

Landon

I think I have a couple here still (in Seattle) from either XJ, MJ, FSJ or AMC Eagle I have parted in the past.

Carnuck,

That's great that you have a couple of switches, would you consider selling one? How much? I really would love to get one.

What part of seattle do you live in? I am actually up north of bellingham but am down to visit my sister in Bellevue quite often.

Let me know

PM me if you prefer

Landon

I'm in Totem Lake (Kirkland) and work at NAPA in Bellevue except thur/fri