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Front not engaging when put in 4x4

EB4X

Explorer Addict
Joined
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Messages
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City, State
Orange county, Ca
Year, Model & Trim Level
95 Explorer 4X 4.0 ohv
Hey gang,
So front axle is not engaging when putting in 4x4 (immediate/low..surely auto as well)..
The transfer case DOES engage but the mechanics/ or whatever is not connecting the front axle.
I crawled under and pulled the vacuum line at the vacuum actuator / engage mechanism to see if that was the problem.... had buddy put into 4 low with vacuum line off to feel for vacuum upon switching but having that pulled (even there) disables the transfer case from being engaged, stops entire process, once plugged back in the transfer case will then work / engage.
I then jacked all four tires off the ground and engaged 4x4 to see if front would turn at all without all the weight of vehicle (to see if maybe a slipping issue) but no front wheels turning at all in 4x4 / in drive / giving it gas.
The 4x4 lights flash twice when turning the switch / engaging transfer case.....once engaged the 4x4 light will NOT come on anymore, letting you know it's engaged but can hear the transfer case clunk during engage / disengage.
Is there any usual culprit that is first to go in this scenario ?
1995 model.

410...where are you! ?? ! ! !
 



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Hey gang,
So front axle is not engaging when putting in 4x4 (immediate/low..surely auto as well)..
The transfer case DOES engage but the mechanics/ or whatever is not connecting the front axle.
I crawled under and pulled the vacuum line at the vacuum actuator / engage mechanism to see if that was the problem.... had buddy put into 4 low with vacuum line off to feel for vacuum upon switching but having that pulled (even there) disables the transfer case from being engaged, stops entire process, once plugged back in the transfer case will then work / engage.
I then jacked all four tires off the ground and engaged 4x4 to see if front would turn at all without all the weight of vehicle (to see if maybe a slipping issue) but no front wheels turning at all in 4x4 / in drive / giving it gas.
The 4x4 lights flash twice when turning the switch / engaging transfer case.....once engaged the 4x4 light will NOT come on anymore, letting you know it's engaged but can hear the transfer case clunk during engage / disengage.
Is there any usual culprit that is first to go in this scenario ?
1995 model.

410...where are you! ?? ! ! !
There are two solenoid on the pass side radiator support, which those two line on the actuator come from.
1. First see if you are getting a signal to engage and unengage at the two solenoid connectors.
2. If that check out, then see if you have vacuum at both those solenoids.
After that test, you will know which system direction Too go.
If above check than do the same test at the actuator.
3. Those check out. Then go to the Gem module, which is between the radio and the pass side air bag. Air bag wall. And see if you getting a command signal to the gem and leaving the Gem.?

? Do you hear the shift motor moving?
***Check the ground connector, on the right hand side of the PCM in the engine compartment.
The actuator engages the front axles. If you have and signal, then the actuator is bad.
!if you have a hand vacuum pump, you can manual test the actuator.
The shift motor, shift 4 high and 4 low and neutral. Check the wiring for a good ground and or bad connection.
the brake switch and the neutral switch need too tell the Gen to switch too change too 4 low.
Do you need the diagram?
 






The only shifting on these is from high to low. There will be no shift between 2wd to 4auto.

They make an adapter to get rid of the vacuum actuated axle. There’s a reason it only hung around 2 years.
 






Hey gang,
So front axle is not engaging when putting in 4x4 (immediate/low..surely auto as well)..
The transfer case DOES engage but the mechanics/ or whatever is not connecting the front axle.
I crawled under and pulled the vacuum line at the vacuum actuator / engage mechanism to see if that was the problem.... had buddy put into 4 low with vacuum line off to feel for vacuum upon switching but having that pulled (even there) disables the transfer case from being engaged, stops entire process, once plugged back in the transfer case will then work / engage.
I then jacked all four tires off the ground and engaged 4x4 to see if front would turn at all without all the weight of vehicle (to see if maybe a slipping issue) but no front wheels turning at all in 4x4 / in drive / giving it gas.
The 4x4 lights flash twice when turning the switch / engaging transfer case.....once engaged the 4x4 light will NOT come on anymore, letting you know it's engaged but can hear the transfer case clunk during engage / disengage.
Is there any usual culprit that is first to go in this scenario ?
1995 model.

410...where are you! ?? ! ! !
I believe its your Gem module. See attached diagram
You don't have indicator lights

IMG_20230526_232745.jpg


IMG_20230526_232652_burst_01.jpg
 






Thanks Pete / Mbrooks... yeah I'll check those solenoids. I thought it was just the ONE was for the 4x4 system / the one closest to fender...that one feeds directly to the actuator / "engager" ...both they are both for 4x4 system for sure?
Mbrooks....do you have a link / part number to this adapter / conversion ? Couldn't find anything here doing a search...
 


















Hey Pete, Is that a Shop manual ? Can you post cover of manual? Is there a free download for that anywhere? When I save those posts / pics as Jpegs they will not open up, I guess E.F. does this in case of copyright issues.....
On other, to recap you are confident that with a poor, or malfunctioning GEM that the transfer case will STILL engage from switch but that the signal to the actuator could be malfunctioning due to the GEM ...?
Also, I'd assume the vacuum solenoid only creates vacuum for a few seconds...to engage disengage ?
 






Hey Pete, Is that a Shop manual ? Can you post cover of manual? Is there a free download for that anywhere? When I save those posts / pics as Jpegs they will not open up, I guess E.F. does this in case of copyright issues.....
On other, to recap you are confident that with a poor, or malfunctioning GEM that the transfer case will STILL engage from switch but that the signal to the actuator could be malfunctioning due to the GEM ...?
Also, I'd assume the vacuum solenoid only creates vacuum for a few seconds...to engage disengage ?
1. The manual is the ford 1995 electrical and vacuum troubleshooting manual. It is offer for alk ford models.
it is listed in your owners manual in the rear pages. Or do a search online.
(313)399-8727 , EVTM p.o. box2592 Dearborn michigan 48121-9973.
$30 on eBay with shipping
2. I think its the gem module, because the indicator light are illuminated by the gem.
3.first see if you get a signal at the two solenoid valves on pass side front corner of the engine compartment. One solenoid is for 2 wheel drive is the 4 wheel drive solenoid.
The vacuum comes from the engine to those solenoids. You should have vacuum at the inlet two both with the engine running.
4. If you don't have a signal there, then you will not have a vacuum passing thru the solenoid too the actuator valve ( function of the solenoid are too engage and disengage the actuator.
5.. If you don't have a signal at solenoids. Go inside the car and remove the radio, too gain access too the 4x4 switch, gem module , 4 wheel drive relay.
6. See if have power at the 4x4 dash switch in and out. There are a few fuse for the system.
7. follow the diagram and test the next component. But first check the ground terminal stud on the firewall beside PCM in the engine compartment.
You can ring out the ground on the connector.
 






Just checked..... when person in vehicle puts it in 4WD I DO get vacuum on BOTH solenoids but NO vacuum down at actuator.....so even though the vacuum lines going down there (in plastic conduit) look in tact... apparently there is a break somewhere from solenoid to actuator .....
 






Just checked..... when person in vehicle puts it in 4WD I DO get vacuum on BOTH solenoids but NO vacuum down at actuator.....so even though the vacuum lines going down there (in plastic conduit) look in tact... apparently there is a break somewhere from solenoid to actuator .....
Are the solenoid being actuated? Pull the connector and see if you have power. You use a bulb, or voltmeter, or test probe.. On each conector, there is a ground and a signal wire. Found out, if you have a command.
 






Are the solenoid being actuated?
I had all the vacuum lines disconnected from them and was getting vacuum / suction off one port of each.....so yes...
 






If it’s not a big job, I’d replace it all. At this age I’d expect all of it to be pretty brittle.
 






I had all the vacuum lines disconnected from then and was getting vacuum / suction off one port of each.....so yes...
I had all the vacuum lines disconnected from then and was getting vacuum / suction off one port of each.....so yes...
1. Are the solenoid being actuated? at the connector, probe the connector and see if you get a command two turn on.
2. Pull the connector and see if you have power.
You can use a bulb, or voltmeter, or test probe..
On each connector, there is a ground and a signal wire. Found if you have a command.
 






1. Are the solenoid being actuated? at the connector, probe the connector and see if you get a command two turn on.
2. Pull the connector and see if you have power.
You can use a bulb, or voltmeter, or test probe..
On each connector, there is a ground and a signal wire. Found if you have a command.
Why would there be vacuum if they weren’t actuated?
 






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