perm lock vs posi lock - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > YJ Jeep Wrangler Forum > YJ Tech Forum

Join Wrangler Forum Today

Thread Tools

Please support our sponsors and let them know you heard about them on
Old 12-09-2013, 06:43 PM   #1
jeremyx28's Avatar
Join Date: Apr 2013
Location: Peckville, PA
Posts: 236
perm lock vs posi lock

My 4wd indicator lights not working. I had a new trans put in, it worked before the install but not after. From what I can tell all the vaccum hoses look good, I crawled under the jeep today and checked everything out. So I was thinking about going with a posi lock system. I'm not even sure if it will fix my problem with the light. I found a perm lock system for 1/2 the price of the posi lock. Being that I have a front lock right locker am I going to run into problems with the perm lock? Also, it feels like my 4wd is working despite the light not coming on, however I read on here that I'm not locked in....

jeremyx28 is offline   Quote
Old 12-09-2013, 08:19 PM   #2

WF Supporting Member
jokerchief462's Avatar
Join Date: Apr 2012
Location: North Las Vegas
Posts: 9,820
You shouldn't have problem with the locker until you select 4H or 4L with the transfer case.

The locker won't engage until it is told to, that is the way mine is working but I have a TJ shaft in the right front and did away with the CAD.

89 2.5 TBI, 4" RC lift, 1" Booms, SYE, Adams Driveshafts front and rear, Ford 8.8 with 4:88s, BFG 33X12.50X15, and a ton of other stuff.

AF Jeep Club Tail Number 184
jokerchief462 is offline   Quote
Old 12-09-2013, 08:56 PM   #3
Join Date: Oct 2013
Location: King George, VA
Posts: 331
Check the 4-way vacuum connection plug where it connects to the top of the tcase.

Its the 4-way connection you can see here in the middle area of the tcase between the 6 tranny mount studs & front output fixed yoke.

Joe Dillard is offline   Quote
Old 12-09-2013, 10:30 PM   #4
OverkillYJ's Avatar
Join Date: Jun 2012
Location: Philadelphia, PA
Posts: 2,904
Check the sensor for 4WD before anything. It is on the CAD housing. Either use a tester to check continuity with it open and closed, or close the circuit on the wire going to the sensor and see if the light turns on.
Complete rebuild axle/engine/everything swap in progress:
Parts already gathered for assembly: 2001 Ford 302, 1990 Mustang GT 5.0 ECU and wiring, NP435, NP205, Pair of axles from 04' F350 SuperDuty (Sterling 10.5 Posi rear, Dana 60HP Front-Both Disk Brakes 3.73 Gears), 37" H1 Tires, 9" lift TJ Coils for 2 link conversion in front, Stage 2 Clutch Kit, 3 Row Aluminum Radiator, Chevy Astro Steering box (4" front Stretch), XJ Rear Leaf Springs (6" Rear Stretch), and lots more.
OverkillYJ is offline   Quote
Old 12-09-2013, 11:09 PM   #5
c5wagner's Avatar
Join Date: Apr 2013
Location: Reno, Nevada
Posts: 1,460
If you feel like spending a bit of time you can do your own posi lock, here's a link to a write up I found on jeep forum when I had 4x4 problems
Home made POSI LOCK write up -
1989 Base YJ, 4.2l, Motorcraft 2150 carb, CRT HEI ignition, ax15, np231 JB conversions SYE, D30 ARB & Ford 8.8 ARB 4.56, 35x12.5r15 Goodyear MTR's, bds 3.5" springs, 1" body lift, and 1/2" Boom Shackles.
Build Thread:
c5wagner is offline   Quote
Old 12-10-2013, 08:43 AM   #6
Fabrokoner's Avatar
Join Date: Apr 2013
Location: Plymouth, CT
Posts: 384
Start easy. Check the bulb in the dash. Then move to the switch. Unplug the wire at the CAD an short the two conductors with a small piece of wire.

Check those and post back. We can trouble shoot further.

If it feels like 4 wheel is working then it's probably one of those two things.

If your 4 wheel is out, then check the vacuum system, make sure you are getting vacuum on the switched side. If not, your vacuum switch may be bad. Then make sure the diaphragm isn't full of rust and mud and moves freely. If both of those are fine pull the CAD cover and make sure your shift fork isn't broken and that the collar slides easily over the splines of the outside axle shaft.

Good luck!

Fabrokoner is offline   Quote

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Download our Mobile App

» Featured Product

All times are GMT -5. The time now is 02:20 PM.

Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC. is not in any way associated with the Chrysler Motors LLC