O.K. here is where I am at. I purchased this truck about a month ago It is a 95 5 speed extra cab 12valvewith 116000 mile on it. 4x4 was working properly on the day I got the truck. Now I can't get the front to engage. Here is what I have done. I pulled the vaccum actuator off the truck today and made sure the fork was working properly it is. The collar slides easy both directions. When the floor lever is pulled to 4x4 the light comes on but nothing engages. Traced vaccum lines the ones going to the actuator on the axle have been replaced elimingating all the metal lines. Traced the white and green line from my t-fer case and go to the engine compartment. I found the green one ends with a fitting making a 90 on it. The white one goes up and to a whole bunch of other lines all that seam o.k. I was guessing that the green one was not just needing to hang out in space so I traced down the only port I could find. It is a brass fitting on the passinger side rear of the engine on top of the bell housing. There is a hose coming in it from the t-fer case and on the othe side was an open port. I hooked up the green line and it still does not work. I need help. I am assuming that the green line is my problem where does it go. Any help would be appreciated.


Also does any one have a picture of the posi locker mounted on the inside of a rig?

 

With the truck running have someone move the transfur case shifter while you check the houses one at a time for vacume , you need to make sure that theres vacume from the vacume pump to the vacume switch at T.C. the that it sends vacume to the accuator on the axial at the right time in both directions , half the time if you can get a understanding of the system then you can work with out a manual or other refrences , just logic , you need vacume , you need to control vacume and vacume has to perform a fungtion- vacume pump-switch-motor.

 

I have vacuum at all 4 stations. I checked the white hose under the hood it has vacuume. The green hose has vacuume/ not sure I have it hooked in the correct spot. The red and black hoses all have vacuume on them. I traced the thing I tied the green hose into under the hood and it goes back to the t-fer case. Not real sure why you would need to loop like that so I think it is in the wrong spot?

 

No vacuum problem.
If the light comes on the front axle shift collar has to be in the locked position. It's impossible not to be since the collar activates the light switch.
You could have an internal transfer case problem that isn't engaging the front driveshaft or an internal problem in the front axle.
I'd get all four wheels off the gound start it up and go from there.

 

I had the front up today when I had every thing pulle dapart. I put the collar in the locked position with the shifter in 4x4 and it worked as it should. I could turn the drive shaft and it would turn tires and turn the tires to turn the drive shaft. I buttend every thing up and no such luck It just isn't locking in for some reason?

 

O.K. had some more time so pulled the actuator off again. This time befor pulling it I put the truck in 4 wheel while pulling in to my drive way. When I pulled the fork out the shift collar was moved but not engaged. It was sitting on the edge ready to go. I did notice on the shift fork the plastic clips were missing off the end. Would this keep it from engaging? I am going to go tomorrow and get the clips for the end and the cork gasket set.

 

Infidel,

IF the transfer case spins, and the four wheel drive indicator dont come on, that surely cant mean its an internal problem in the T case can it? I already have the posi lock on the way and dont want to feel than what i already am..

Thank you

Tx

 

Tx, VPI is saying his light is coming on but no 4wd

 

I had similar troubles on the 97 4x4 that i had , i had vaccum at both red and blacklines down on the actuator , and the white line was teed in with a bunch of other lines eventually making it's way to the vaccum pump , and the green line was just hanging there in the engine bay , apparently going nowhere.

The actuator did not function , the truck was in 4x4 all the time , if i slid the actuator over and slide the collar over so it was in 2wd , it wouldn't move back to 4x4 , and vise versa.


If i took the actuator into the shop , and very lightly shot some compressed air into either of the vaccum ports , the shift fork would quickly snap over to the opposite position from where it was , so it seemed to be functioning normally.



I never did figure out that the problem was , i just lived with it for the week i owned the truck.

 

I have to agree with infidel. The light works off of the front vac motor and comes on only when it moves. Put it in 4x4, drive it a couple of feet - shut it off and jack up the front end without taking it out of 4x4. Make sure the front drive shaft doesn't spin with it in park or gear. If it does spin, then something isn't engaging in the transfer case. Next try to spin the passengers side wheel. It should spin either the other wheel or front drive shaft if everything is engaged.

 

I have done this and the collar that locks every thing into place is not moving all the way over yet I am geting a 4x4 light in the cab? It is sitting pushed up against the side that would lock every thing into place. there is a little space inbetween the two shafts and that is where it is stopping. With it in 4x4 the drive shaft will not turn freely and with it jacked up the passinger tire will not spin the drive shaft. If I manually ingage it, it all works as it should. I just orderd the shim kit with the new cork gasket and bolts. I hope that putting the shims on the end of the fork this will help.

I did figure out that the green vacuum line is a open vent and should not be hooked to anything.

Thanks for the help so far any mor would be appreciated
Tom

 

Not sure on the colors but I don't recall a vent line anywhere. The two lines at the actuator are both vacuum, one sucks for 4wd and one for 2wd.

 

Mine appeared to have vaccum at both lines on the actuator , no matter where the t-case shifter was located. is it possible whatever switches the vaccum from one line to the other was muffed up?

 

The vent is up on the fire wall near the fuel line hoses. Do you have any oil in the lines? That tends to cause the vac system to not work properly. The connector on top of the transfer case also will swell a little if it's exposed to oil. You have 4 lines on this thing: 1) vac feed to the switch, Vac to engage, Vac to disengage, vent.

I got rid of my vac motor and converted to a Posi-Lok. Had similar problems....

 

O.k. got the clips in and on today. 4x4 locked in no problem the first time. I took it out and locked in again and it would not go. Put the truck up on the stands and rear wheels turned but not the front. Pulled the shift motor off again while the truck was in 4x4 and it was stuck inbetween and did not lockin. The gear the shift collar slides over appeared to have been scared this time some fresh metal showing through. So I start checking every thing again all checks out. I notice one of the clips I just put on has moved out if the groves . As I am re-replacing the clips I notice it has a gash in it like the collar was pushing really hard aginst it. the collar still slides easily back and forth over the gears.
Things I noticed. If I manually move the shift fork all the way over to 4x4 side and put over the shift collar it does not look like it moves the collar far enoughf to the left? Again the shift fork is as far over as I can get it. Is the distance adjustable? The other thing I noticed is when it is locked in the front tires spin opposite directions when the t-fer case is in 4x4. If the t-fer case is in 2x4 only one tire will spin even with the shifrt collar pulled over the gears. Would my front end be antislip?
Things I am considering. If a posi locker will pull the shift collar all the way over I will go with this. If not I am considering tacking the shift collar in the 4x4 position letting the front drive shaft spin all the time and just using the t-fer case to take me in and out of 4x4. I will lose a little fuel milage and a little mor wear on the front end but I should always go into 4x4.