Modifying D30 vac disconnect motor question

My final step on the 4WD conversion is about ready to happen. I'm swapping in a disco D30 and am debating how to deal with the 2 pc axle shaft until I replace it with a solid one.
In order to "lock" the shift fork on a vac-disco D30 in the engaged position, couldn't you simply tap into the vac line from the vac canister and run it straight into the vac motor on the axle? I know there are other possibilities, like shimming the shift fork over, or a cable actuator, or even (gasp!) swapping in the entire vac harness assembly, which I do have one of but really don't want to deal with all that hassle....but wouldn't a constant vac source on the "engage" side of the vac motor keep the axle shaft locked together? I'm just trying to keep it simple at this point until I can put a one piece shaft in and not have to worry about it anymore. Anyone see a down-side to running a constant vaccuum to the CAD motor?
TIA,
Jeff

just use small hose clamps to hold it where you want it that is how mine has been for about 6 months now. don't put the clamps on the housing but on the smaller shaft that moves with the vaccumme.

Jeff, don't sell the Vac-Disco 30 short. On my 89 with a 231 t-case, I've been running a console mounted vac switch (3way switch -Single Pole Dual Throw type-from an HVAC shop) for a couple of years, which allows me to have the luxury of 2 Low by merely flipping the switch and unlocking the front axle while in 4 Low. I love this mod. Simply route the vac source line from the vac res. bottle up through your dash to the switch, then run tow lines back out to the axle motor-one to push, one to pull. Plug all three lines up to the switch and you now have manual vac disco. The tcase switch can be completely bypassed.
Let me know if you need more details.

DOH! I have CRS disease....

Thanks for jogging my memory for me..I have a write-up by BillaVista about that, using the vac switch from a Command Trac (or is it Select Trac??) XJ/Wagoneer. I forgot all about that until you mentioned it....and I do know there's one in a U-pull yard down here I could grab for cheep. That just may be the answer, and I could run a tee off of the engage line and run some vac for the little 4WD dash light too.
BTW, I did pull an entire vac harness from the U-pull, only cost me $3.27 'cause they had no idea WHAT to charge for that ungodly mess of vac lines, tubes, and what not. Ever see a whole assy. out of the vehicle?? What a mess of crap that is But I have plenty of pieces/parts to make anything work.
Thanks!
Jeff

p.s.-> Bucky, your method was/is my backup plan, thanks for the reply!

Yeah mine was temporary but I never got around to messing with it. I was going to do a cable though like the posi lock but not $200

I've plumbed the vac lines to a swithc in the dash to do the unlock/lock at my command. Use a Clippard switch and some air fittings........

I'm planning on running a vac switch I pulled from a qudra trac FSJ Cherokee.

I'm guessing the three hoses are vac supply, then one for engage, one for disengage.

I fought this yesterday - the vac wouldn't throw, and had to drive through my neighbor's field to get out. At least I don't have to weed eat the hill now, small consolation for getting embarrassed in front of the wife and neighbor.
I agree, a $200 cable isn't in my budget, (Cripey mates, that's an Aussie Locker!) But the bike cable / mower throttle mod for $20 is a little too , um, light duty. I suppose I could plumb a vac switch but I'm old school - I remember vac wipers - so a cable mod seems more sure to me. And I like taking out the factory answer and throwing it in a corner of the garage! Sheesh, tyraps on the hose connections? I'd rather tyrap a new cable and get manual. I guess it's a mechanical thing.

Looks like lunch this week is TSC and Atwoods.

Maybe this is a stupid question but oh well here goes...Can you use the same t-case from a vac operated system with a front axle that is not vac operated? TIA

Justin

yup I have a non disco axle and 231 case just plugged the lines at the axle shifter

Thanks, I figured it would be something easy but oh well. I appreciate the help.

Justin