very common mod. search for posi lock.

 

the FAQ section is your friend

http://www.jeepforum.com/forum/f12/home-made-posi-lock-write-up-595515/

or if you want to get crazy
http://www.jeepforum.com/forum/f12/...cuum-disco-elimination-axle-tube-sleeve-fix-ubolt-eliminator-56k-beware-793813/

 

I just went through a similar search last week, thinking to replace my disconnect.

However, I researched how the system works. Once I understood it, I repaired it in about 2 hours. Pulled the whole vac harness, repaired it, tested it before reinstalling, and reinstalled in jeep. I now have it protected and routed in a way that protects it well, and it cost me 3 bucks for some vac lines and tape.

Its extremely simple. 90% chance your vac motor is fine. There are 4 plastic lines that have to be intact. If they crack or leak, the motor will not work. Fix the leak (easy!!!) and it will work perfect.

No need to mcguyver something up and dont wast 250 bucks on a posi lock.

Yes The posi lock does work, but I'm spending my money elsewhere, and I am absolutely positive that the vac motor will work everytime i shift into 4wd. In the off chance it doesent, if you understand how it works, you can get it to go into 4wd with out using your factory harness anyway.

Newfie

 

No need to mcguyver something up and dont wast 250 bucks on a posi lock.

Newfie

for a $29 dollar locking choke cable and a few small parts its a str8 forward and reliable mod. he said his vac motor was all rusted and they sell for $80.

 

Newfie: Did you get your info from the Factory Service Manual or where?
Thanks for the shout and best of luck to you!

 

There's a whole break down on the vac system in the FAQ's. Yest the vac system is simple, when it works. Personally I got rid of mine with it quit and did the homebuilt posi. That also worked fine, but I eventually swapped in solid shafts and was done with the whole disco thing.

 

Better yet, go to the junk yard get a set of TJ axles shafts and eliminate the disco completely.

 

I agree that it may be worth it to some to remove the vac system and go manual cable. However, I've seen people having adjustment problems with cables, and that is just as unreliable as the vac lines.

Jeep put it on the YJ because its a good system and does work. It does however, need to be maintained.

The rig is 20 yrs old. If the vac lines havent been maintained, of course its gonna act like a Piece of ****. If you didnt maintain your engine, change the plugs, or oil, or just drove it for 20 yrs, it would be the same thing.

AND, now, almost 20 yrs later the disconnect is finally starting to give out...That aint bad if it worked for the first 15-18 yrs trouble free.

Yes, posi lock works. Yes, Solid shaft upgrade is definitely good, if your front driveshaft is balanced and you dont mind it spinning all the time.

But, It is EXTREMELY cheap to at least test the original system. 5 mins and 4 bolts will tell you if your vac motor is working. 5 mins with the motor running to see if the switch in the TC is working. If it is, unplug the harness, fix the leaks, tape it up, package it well and put it all back. It will probably work for another 15-18 yrs.

T.Maxwell dont let a little rust scare. I have a parts YJ here that rusted so bad the chassis broke in half.... the Vac motor still worked.

If you want a break down of the vac lines and colors and how to test the motor, search this board or I can tell you what I did with mine.

Newfie

 

Jeep put it on the YJ because its a good system and does work. It does however, need to be maintained.

Jeep also got rid of it for the TJ's because it was a problematic system even before they were 15 to 20 years old.

I'm glad you were able to get yours fixed on the cheap. Let's not turn this into a pissing contest because everyone else didn't do the same. :cheers2:

 

i like having the two piece axle. when im in low range on a granite slab and need to turn it helps to be able to unlock the axle while in 4 low

 

if i were to use the vacum motor i would repipe it to solenoinds controlled by switches on the dash and not controlled by the transfer case switch

 

that is exactly how mine is set up

 

brian you got a write up on how you did the switch setup? thanks!!!

 

I didn't really do a write up, But it is very straight forward. all you need is a 3 way toggle, 2 vacuum switches, wire and some vacuum line. I got my switches from the junk yard off an 80's ford. then you just run the wire so that 1 way on the toggle activates one switch and the other way activates the other. then just run a constant vacuum to the switches and run a line from each switch to the vacuum motor and have fun. once the switch has power it allows the vacuum to go past the switch. I have been considering doing a write up for some time now, But just haven't

 

Brian, you said you ran a 3 way toggle. I can see one way for off, and one for on.... what is the other for?

 

it goes on-off-on. each on side runs power to a different vacuum switch

 

Sorry if this is ignorant, but I dont get it?? WHy would you need 2 switches for on? Redundancy??

 

because you need 2 vacuum switches. You have to have vacuum to slide the fork and connect the axle and you need vacuum on a second port to move it back and disconnect the axle. so running a 3 way toggle allows you to have only one switch inside rather than 2 separate ones

 

Ahhhhhh got ya! Was initially thinking that taking away vac would disingauge.

 

QUOTE]Let's not turn this into a pissing contest because everyone else didn't do the same.[/QUOTE]

Sorry if I'm too opinionated! Apperently my wife says the same!

I am very interested in the toggle switch setup. Do I understand correctly that this can give you 2 Lo?

Newfie

 

if your still open in the front. if you have an auto locker like an Aussie then its 3 wheel low. but its still better than all 4 when turning on solid ground. the only problem with 3 wheel drive is if your on ice it will send you into a 360 faster than you can react. ask me how i know! you know those relays that the carbureted jeeps have that are mounted at the back of the engine bay. they work perfict for making the toggle switch setup.
maybe brian will enlighten you with pics and a diagram

 

anybody have a diagram or photo of this setup?

 

I wish I had done more research on this mod. I ended up purchasing an XJ
front Dana 30 for $200.00 bucks, for the High Steer Kit it had on it. I was
talked into swapping the front, right, solid, XJ shaft as an upgrade, at the
same time. Not only does this limit my options, it killed my street ability on
MPG. I still use this as a DD. I didn't use the block off plate so I still have
the Vac motor and lines. My outer seal is now leaking so instead of pulling
the axle to repair the seal, I will pull it and replace it with the 2 piece shaft
and Vac disconect, with the set up mentioned here. Thanks for the info ...

92YJ/2.5L/5-Speed/D30-35/4.88's/AX5/N231J
TeraFlex High Steer Kit/Solid Front Axle Conversion
Super Coil/Live wires/14" E-Fan/4L TB/19lb Injectors
AA-SYE/CV Rear DS/1" Lift S-Reversal Kit Up Front
1" lift Shackles Rear/4" RC Lift SUA/1" Daystar Body Lift
Hack and Cut Flatty Front Fenders/TJ Rear Fender Flairs
35x12.5x15 BFG TA KO's/15x10 AR Outlaw 1 Wheels
High Lift Jack/D-Rings/9000lb Winch/Tow Hooks

 

I had a perfectly working vac system and replace it with a posi loc after installing the Aussie. . Last month i got it onto my head that i wanted to remove the PL and install a solid shaft.
My next thought was to keep the stock shaft and just put the factory vac housing back in and just permantly e clip the fork over to the connected posistion as it is now.
I now get a vibe while driving can picture that wheel on the lock out fork spinning unnecessaraly
I will be reinstalling the posi lok today

 

Posi-lok is back in and working:2thumbsup:

 

Does anyone have any experience with switching to tj shafts? My plans was to swap shafts and pick up a Tom Woods front shaft. Any thoughts on this route?

 

I swapped in TJ/XJ shafts and had zero issues.

 

Like I said, I did swap in the TJ/XJ solid, right, front shaft with no problems.
What I was trying to say is that it killed my MPG as I use my rig as a DD.
Other than that, I have had no problems. I went from 16-18 Mpg to about
11-13 Mpg

92YJ/2.5L/5-Speed/D30-35/4.88's/AX5/N231J
TeraFlex High Steer Kit/Solid Front Axle Conversion
Super Coil/Live wires/14" E-Fan/4L TB/19lb Injectors
AA-SYE/CV Rear DS/1" Lift S-Reversal Kit Up Front
1" lift Shackles Rear/4" RC Lift SUA/1" Daystar Body Lift
Hack and Cut Flatty Front Fenders/TJ Rear Fender Flairs
35x12.5x15 BFG TA KO's/15x10 AR Outlaw 1 Wheels
High Lift Jack/D-Rings/9000lb Winch/Tow Hooks

 

I still run my stock system. It's only been problematic once when it wouldn't disengage but a some carb cleaner and WD-40 fixed that.

I also re-routed a 3 way toggle vacuum switch that I got off a Wagoneer at the junkyard. It worked great but after I got a locker and ripped the 4wd switch out of the axle I just hooked up the original system. Since the switched was ripped out on the trail I couldn't visibly tell if my axle was engaged or not and would not disengage it sometimes.

I ended up sending the switch a member on JF for free and now I'm planning on new XJ shafts once the stock system fails but that's just my :2c:.

 

Havent hooked up the 4wd light wires yet, maybe on the next warm day. today was weird weather with temps in the 50s

 

I know this an old post but has anybody attempted to build an electric piaton/actuator to control the disconnect instead of vacuum

 

Someone tried one with an electric actuator. Its just so much easier to lock the fork over and not have to mess with any go go gadget buttons.