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-   -   95 YJ 4wd not working (kinda) (http://www.wranglerforum.com/f218/95-yj-4wd-not-working-kinda-167185.html)

Humpty Dumpty 95 06-16-2012 08:14 AM

95 YJ 4wd not working (kinda)
 
I know in the process of the 3 yr project I may have put something in wrong but here's the deal. New fork, vacuum actuator, old lines, new sending unit and all new seals in front axle assembly. When I put it in 4wd I do not get a light or IMO 4wd at all. I do however feel it in my transfer case as a gear reduction or??? Any ideas on where I went wrong or options to fix so I can go wheel?

Tyewilly 06-16-2012 08:30 AM

I would start by checking the vacuum at the actuator. Engine running in park or neutral, you should have vacuum on the passenger side line in 2wd. Then shift the t case into 4wd and you should have vacuum on the driver side line. Also the opposite line should have no vacuum and should be vented to the atmosphere. If the vacuum is in the wrong place, the vacuum connector is hooked up to the t case switch incorrectly. If there's no vacuum or poor vacuum, either something isn't hooked up right, or you have a leak.
If the vacuum checks out ok, jack up the passenger front only and check to see if you can turn the wheel in 2wd and 4wd (engine running, park or neutral as before. If the wheel spins, check to see if the front driveshaft spins with it. In 2wd the wheel should spin freely and the driveshaft should stay still (unless you have a locking differential). In 4wd nothing should spin. If this isn't the case then you have a mechanical problem somewhere.

Humpty Dumpty 95 06-25-2012 09:10 PM

Checking the vacuum and I find only the drivers side of the axle vacuum lines works both in 2wd and 4wd?

mcgyver1467 06-25-2012 09:16 PM

This is what I came up with when I re-did all mt vacuum lines on my 87.



(blue line) Leave hanging, it has a check valve on it which gets hooked to nothing.
(red line) Hooks up to a good constant vacuum source off of the manifold.
(green line) goes to the shift motor on the front axle. Horizontal on the shift motor.
(black soft vacuum hose) goes to the plug on your firewall by the battery for the 4wd indicator on the dash.
(yellow line) goes straight to the shift motor; one of the lines that goes into a two line plug verticle on the shift motor.
(black hard line) goes with one of the yellows to the shift motor. Plug located vertically on top.

Tyewilly 06-26-2012 12:34 PM

Sounds like something is wrong with the vacuum switch on the transfer case, almost like it's not threaded into the t case far enough for the shift rail to activate it. A '95 only has four vacuum lines. One to manifold vacuum, one that is vented that hangs by the battery, and two to the actuator. The switch for the light is on the cad housing and is activated by the rod for the cad fork.

Squeeze 06-26-2012 12:36 PM

Just go posi-lok :D

Humpty Dumpty 95 06-27-2012 09:37 PM

Yes posi lock is a no brainer BUT this was taken down to every nut and bolt and rebuilt for my 16 yr old daughter. Took it to basics for now with only a 2.5 inch lift:thumb:

Humpty Dumpty 95 06-27-2012 09:55 PM

I've checked the seating of the connector and it is good. I did buy this hose assembly of eBay and I just found my original that was plugged due to a posi lock previously installed. I will swap vacuum lines then go for there

Squeeze 06-27-2012 10:41 PM

Let us know how it goes, I'm eager to find out what it turns out to be

YJ325i 06-27-2012 11:03 PM

Was wondering, can you just use a vacuum pump (mighty-vac hand pump) to activate the cad on the axle to at least check its operation? While having the RF wheel jacked up as prev. mentioned. Could also see if the 4wd indicator light comes on. Could do this w/ just key on I'm thinkin'. Good write up Tyewilly. Me thinks you have dealt w/ this a few times. :)

Humpty Dumpty 95 07-01-2012 03:40 PM

Replaced vacuum actuator on transfer case and I still only have vacuum on drivers side? Old one came out sticking and was not "actuating" like the new one. I just drove it and still nothing? I also noticed that I go from 2H to Nuetral to 4 L. No 4 H?

Tyewilly 07-02-2012 10:32 AM

It sound like your linkage is out of adjustment and the transfer case mode fork is staying in the 4wd position. The "correct" way to set it is to put it in 4 low, loosen the adjusting bolt on the linkage rod, and move the shifter back in the shift gate to leave 1/8" clearance between the shifter and the gate (an eighth inch drill bit works well). Then tighten up the adjusting bolt and check the operation of the shifter.
After that you can get the vacuum sorted out. Since it's getting vacuum to the passenger side in 4wd, you'll probably wind up switching the lines at the actuator.

Humpty Dumpty 95 07-08-2012 02:39 PM

Did i mention that i dropped the transfer case 1 inch when i added the lift? Adjusted the shift linkage as per the instruction. I have all 4 wheels off the ground on jacks. 4 hi does not work. 4 low spins front driveshaft but not axle. Hooked up a hand vacuum pump to the fwd actuator and could not get the front axle to engage. So I have a vacuum issue, front fork issue and shifting issue?

2LeftHands 07-24-2012 10:52 PM

Quote:

Originally Posted by Tyewilly (Post 2479210)
I would start by checking the vacuum at the actuator. Engine running in park or neutral, you should have vacuum on the passenger side line in 2wd. Then shift the t case into 4wd and you should have vacuum on the driver side line. Also the opposite line should have no vacuum and should be vented to the atmosphere. If the vacuum is in the wrong place, the vacuum connector is hooked up to the t case switch incorrectly. If there's no vacuum or poor vacuum, either something isn't hooked up right, or you have a leak.
If the vacuum checks out ok, jack up the passenger front only and check to see if you can turn the wheel in 2wd and 4wd (engine running, park or neutral as before. If the wheel spins, check to see if the front driveshaft spins with it. In 2wd the wheel should spin freely and the driveshaft should stay still (unless you have a locking differential). In 4wd nothing should spin. If this isn't the case then you have a mechanical problem somewhere.

I have a 91 Wrangler with the same problem. I checked the vacuum in 2WD and had vacuum on the passenger side and on the driver side in 4WD. The other difference is that my 4WD indicator comes on when shifted to 4WD. For kicks I turned the connector around on the actuator the 4WD indicator comes on in 2WD. Should I be able to hear the axle engaging and disengaging?

Beachrider 07-24-2013 07:48 PM

4 wheel drive information
 
Just purchased a 1995 wrangler 2.5 4speed. I just switched out my 4 wheel drive indicator switch on the front axle and it works. Now when in 2 wheel drive light stays on and my front drive shaft turns. When i take off both vacuum lines to the front axle where the cad is the front axle stops turning and the light goes off. I only have vacuum on one line and thats the driverside line, passenger side, nothing.The 4 wheel drive seems to work good, i was on the beach with soft sand and she did good.What do i do?:banghead:

rbro7752 07-25-2013 10:11 PM

not to get off topic but I have a 88 yj with a 350/th350 swap advance adapters connects the np231 tcase to tranny the yj has a 4inch sua lift when I try to engage 4 wheel drive the whole z gate moves. are there any tips to fixing that?


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