94 jimmy, front axle wont unlock

[GT55]

Had the tranny rebuilt. The shop guy said the front axle won't unlock. Had to replace a faulty axle acuator (rubber split). But know it keeps constant pressure on the cable that runs to the axle. With this constant pressure on this cable, the axle stays engaged. I disconnected the the cable from the axle acuator, which now leaves the axle to free wheel.
Is there a vaccum switch that might be bad? Or maybe the vaccum lines were hooked up wrong at the tranny? I have a Hanyes manual and it does not cover the vaccum system routing.

Thanks for the help



GT

[MT-2500]

Originally Posted by GT55

Had the tranny rebuilt. The shop guy said the front axle won't unlock. Had to replace a faulty axle acuator (rubber split). But know it keeps constant pressure on the cable that runs to the axle. With this constant pressure on this cable, the axle stays engaged. I disconnected the the cable from the axle acuator, which now leaves the axle to free wheel.
Is there a vaccum switch that might be bad? Or maybe the vaccum lines were hooked up wrong at the tranny? I have a Hanyes manual and it does not cover the vaccum system routing.

Thanks for the help



GT

What transfer case?
Manual or electronic?
Does front drive shaft unlock?

Check wiring and vacuum lines and vacuum switch.
Make sure vacuum is releasing on actuator.
And actuator cable.
http://www.automotiveforums.com/vbul...d.php?t=572914

Haynes not much on it.
Factory manual or http://www.alldata.com/products/diy/index.html
Look under hood for vacuum diagram.




Bad actuator diagram will keep it from locking in not unlocking.

[GT55]

Manual
Front shaft turns with front wheels
Actuator has constant vacuum no matter what gear I'm in.
Cable free to move.
Where is the vacuum switch?


Thanks

GT

[MT-2500]

Originally Posted by GT55

Manual
Front shaft turns with front wheels
Actuator has constant vacuum no matter what gear I'm in.
Cable free to move.
Where is the vacuum switch?


Thanks

GT

What transfer case?
Does front drive shaft unlock fron transfer case?

[MT-2500]

Originally Posted by GT55

Manual
Front shaft turns with front wheels
Actuator has constant vacuum no matter what gear I'm in.
Cable free to move.
Where is the vacuum switch?


Thanks

GT

What transfer case?
Does front drive shaft unlock fron transfer case?

[GT55]

OK....the transfer case is NOT in question here. The front drive shaft turns as the front wheels turn. I have disconnected the cable from the axle acuator. Now the front wheels turn without the front drive shaft turning. I have looked for a vacuum diagram anywhere under the hood. It is not there. Where is the vacuum switch located?
Keep trying my friend, I am a little slow.

Many Thanks

GT

[MT-2500]

Originally Posted by GT55

OK....the transfer case is NOT in question here. The front drive shaft turns as the front wheels turn. I have disconnected the cable from the axle acuator. Now the front wheels turn without the front drive shaft turning. I have looked for a vacuum diagram anywhere under the hood. It is not there. Where is the vacuum switch located?
Keep trying my friend, I am a little slow.

Many Thanks

GT

I am afraid the transfer case question is important.
We need to know what transfer case you have to be able to help you.
We have asked about 3 times.
If you want to tell us we will help.
Other wise no help from my end.

[GT55]

OK. Where can I find out what type of transfer case it is? Where is the vacuum switch located?

Thanks

GT

[MT-2500]

Originally Posted by GT55

OK. Where can I find out what type of transfer case it is? Where is the vacuum switch located?

Thanks

GT

Vacuum switch depends on what transfer case you have.
What kind and how many push buttons for transfer case or flood shift for it.
Transfer case ID tag is on back of transfer case?

Is front drive shaft disengaging from transfer case?

[GT55]

I will look for the ID tag on the transfer case. I have a shift lever not the buttons. On the transfer case shifter, from the top is 2 hi next down is 4 hi next down is neutral next down is 4 lo. I wil also look for the vacuum switch somewhere on the transfer case. From other posts I have looked at this switch might be contaminated with tranny fluid and not working properly. I will put the truck on stands in a couple of hours and check all this info.

Thanks

GT

[MT-2500]

Originally Posted by GT55

I will look for the ID tag on the transfer case. I have a shift lever not the buttons. On the transfer case shifter, from the top is 2 hi next down is 4 hi next down is neutral next down is 4 lo. I wil also look for the vacuum switch somewhere on the transfer case. From other posts I have looked at this switch might be contaminated with tranny fluid and not working properly. I will put the truck on stands in a couple of hours and check all this info.

Thanks

GT

Switch should be on transfer case on that one
Look on top side for 2 vacuum lines to it.
The see if switch switches vacuum when moving from 2W to 4W and back.
And see if front drive shaft is locking and unlocking.
Let us know what you find there.

[GT55]

All right here we go. I have a New Process 231 C transfer case. The transfer case vacuum switch is located on the transfer case next to the transfer case shift lever. The vacuum switch has 3 black vacuum barbs on it's top. The vacuum hoses attached to this switch appear to be good shape but the ends attached to the switch are ragady as hell. They are sealing but it is appearent that these hoses have been pulled off in the past. The ends of the hoses attached to the switch, look like they were feed to a meat grinder. It appears one hose goes to vacuum supply, one hose goes to a vent and the third hose goes to the axle acuator. How can I troubleshoot this transfer case vacuum switch? As said before, there is constant vacuum on the axle acuator no matter what gear I'm in. Because of it's location on the transfer case, it will be a bear to change out!!!

Thanks all, keep the comments coming...


GT

[MT-2500]

DOES TRANSFER CASE SHIFT 2W TO 4W AND BACK?
FRONT DRIVE SHAFT UNLOCKING IN 2W?

You need to repair plugin end/hoses if bad.
Make sure hoses are not pinched or full of fluid.

As said and asked before make sure transfer case is shifting 2W to 4W and back.

Does the front drive shafrt unlock in 2W.
Does the switch switch vacuum 2W to 4W and back to 2W?

[GT55]

Lever shhifts from 2 hi to 4 lo and back.
Front drive shaft did unlock before the tranny was rebuilt (to the best of knowledge).
I had to unhook the axle actuator because it held constant vacuum on the cable and that caused the axle to be engaged with the frnt drive shaft.
To make things easier, please send me a pic, diagram, drawing or anything of how the vacuum switch, on the trasfer case, is routed to the 3 components it is hooked to. I think when the tranny was rebuilt they messed up the vacuum lines running from the switch. As well as how to trouble shoot the vacuum switch.

Thanks

GT

[MT-2500]

Originally Posted by GT55

Lever shhifts from 2 hi to 4 lo and back.
Front drive shaft did unlock before the tranny was rebuilt (to the best of knowledge).
I had to unhook the axle actuator because it held constant vacuum on the cable and that caused the axle to be engaged with the frnt drive shaft.
To make things easier, please send me a pic, diagram, drawing or anything of how the vacuum switch, on the trasfer case, is routed to the 3 components it is hooked to. I think when the tranny was rebuilt they messed up the vacuum lines running from the switch. As well as how to trouble shoot the vacuum switch.

Thanks

GT

Sorry I do not have pictures.

We need to know if the front drive shaft unlocks in 2W now.
Not before.

Vacuum lines to transfer case switch should be one for engine vacuum.
One to front axle actuator for vacuuming in 4W
And other one vent to release vacuum in 2W,

Check switch for switching vacuum 2W to 4W and then releasing vacuum when switched back to 2W.
Also make sure lines are not plugged or kinked and that plug in at switched is not turned wrong.

Let us know what you find there.