Hi again. new problems with the same topic. btw Thanks in advance. Took a trip to Indy on the way home lost a wheel bearing. Replaced them both. No problem. Prior to trip 4wd worked. while diagnosing wheel bearings, 4wd worked. After replacing bearings, 4wd no work (^*%(&^%(&%E)*& dang 4wd). Past info. jogging the motor, and removing/reinstalling got 4wd working. I think i got something out of synch when doing the wheel bearings. Turning the front axles/CV's/Ujoints, and front driveshaft. this past weekend removed the motor while connected and hit eletronic 4wd switch. motor actuated so i put it back on. The nothing. Also, if I manually turn the xfer case 2wd,4wdh,4wdl pin. will the 4wd engage? driveshaft from xfer case didn't turn. Aghhhhhhh!
And for all those interested Cruise still no worky.Whaaaaaaaa {:-()>

 

Couldn't quite sort out what exactly isn't working. Is the transfer case engaging or not?

 

Correct couldn't get the transfer case driveshaft to move. I was able to actuate the motor then It wouldn't. If I manually move the 2wd,4wd Hi,4wd Lo switch, should't the xfer case driveshft try to engage the 4wd?

 

Correct, you can manually move the shaft that the shift motor rotates. If you manually put this to the 4H position, and the t-case still doesn't engage, I would expect you have a problem with the shift fork inside the t-case. I would call this a very uncommon failure for the 13-54, but, as I think about it, it seems I have heard of a few cases where the shift fork dies.

 

MrSHorty let me say I do appreciate your input. What kinds of things would cause the shift fork to fail? I wonder because the 4wd engaged prior to me changing the wheel bearings. Is there something I could have done say manually turning the front driveshafts (xfer case to front axle and the CV to the rotors) to get the shift fork disengaged or out of sync? Also do you know if manually turning the shift pin that the motor turns to engage the 4wd also requires the motor to send a signal to the computer so all the parts know its ok to engage? I hope I'm not asking stupid questions. The reason I do ask because I'm fairly decent at automotive repair but an Xfer case would probably have to go out to be done.

 

"Is there something I could have done say manually turning the front driveshafts (xfer case to front axle and the CV to the rotors) to get the shift fork disengaged or out of sync?" -- nothing you could have done that I'm aware of would have caused a problem with the shift fork. Pure coincidence that it decided to fail at the same time as you were fixing your wheelbearings??

"Also do you know if manually turning the shift pin that the motor turns to engage the 4wd also requires the motor to send a signal to the computer so all the parts know its ok to engage?" -- Nope. The only thing controlled by the shift computer is the shift motor. Everything else (hubs, etc.) engages mechanically when power is applied to the front driveshaft.

 

Ageed. If it is broke, what broke it was hitting the 4WD button. No relation to any of the drivetrain parts.

 

Thnks to you both. Seems like I may have to have it looked at and then I'll know. It's very strange that the shift fork or Xfer case parts would stop working as well as the motor intermittantly operating, at the same time I changed the wheel bearings. There was no noise or clunking or no sign of any kind. Oddly enough while troubleshooting the wheel bearings to determine if it was a bearing fail, I engaged the 4WD and it worked. After the bearing replacement, to check operation and my work, The 4WD would not engaged, light on the shift button didn't work (i.e motor didn't turn the shift pin) and of course motor wouldn't operate. I will let you know what I find. This is an intersting anomoly. Here's another question regarding the shift comp/module. (The one in the driverside back quarter, in front of the jack) I can't find any info on that. Something about testing or operation would be very helpful. I know there's some kind of button that lights an LED on the module. What does that do. Is there a quide to troubleshooting the module?
Voltages/ ohms to know if the module is good?

 

I reread you first string. I'm not sure if you have the actuator assembly (motor and sensors) operating correctly. You say the motor spins when removed but not when installed. Did you try to rotate the assmbly to re-align the sensors when you put it back on? It is very possible to install the assembly, even up to 5 degrees off, and loose the actually positioning - the signal back to the computer.

My comments about the shift fork being broke meant that if that is, it was from the motor actuating it and something withing the t-case not allowing it to move resulting in said breakage. If your motor is not turning when installed, how can that happen?

Funny timing on this between you and I. I have the lost $WD engagement problem too and will tackle it this weekend. I will use the collective wisdom found on this page

http://draco.acs.uci.edu/explorer/

to fix it. I'll go ahead and take the entire actuator assembly apart. Should be interesting what I find since I bought this thing new in 1993 and have probably engaged 4WD only 50 or 60 times, I can't believe there to be too much wear, broken parts or dirt build up.

Check out the info on this page under "the trasfer case".

Good luck.

 

Hey Thanks all I got the 4wd an 4wdLO working again. Followed the steps on removeing the motor. and voila. I do have some things to add that are my own insight.

First on removeing the motor. Connector tabs are a push (at the very end).

Also, the wires can sefely be removed by following the instuctions about removing the red center ring and carefully prying back the lock tabs in the connector.

When opening the motor armature; there are tabs on the cylinder for reassemble (or Mark it) also the brushes can be held back manually while inserting the armature, the put the armature cylinder then the end cap.

Important note about the worm gear section. I had to take it apart and clean the inside of the worm gear sensor pad ( cap also has tabs to line it up) Then after I assembled it I ohmed out the connector wires on the motor. Continuity between 6,8,10 while open between 7,10 & 9,10. refer to http://draco.acs.uci.edu/explorer/ for other diagrams and such.

I also had to index the worm gear so the motor would realign onto the transfer case with ease. and rechecked the ohms test again. Thanks for all your help.

 

Cool news! Nice having 4wd back isn't it? I fixed mine too the next weekend after my last post. As suspected, my assembly was very clean. Minimal soot around the brushes and copper pads they ride on. The sensor plate with the printed circuit board traces looked fine but I cleaned all that off anyway.

I also had no issues removing the brown wire from the connector that derives from within the transfer case. I used a small pick tool that I had to remove the, red on my truck, inner plastic retaining peice inside the connector. One could fabricate such a tool with a thin paper clip bent 90 degrees at the end about .03"-.04" long. Then, a small screw driver to hold the plastic clip away from the metal pin and then push the pin through the back. One does need to be a little cautious here though because the metal pin is has 3 slits down the lentgh to give it some spring inside the female side when conneted. This makes the pin not as strong as it looks - it is not solid metal.

So then, if mine was so clean, why didn't it work? The worm gear has a screw inserted such that its head acts as a stop on the inside of the housing once installed. I'm not certain on this part, but I think the PCM uses time to move the motor to the 2 extreme positions - 2wd and 4wd low. Thus the PCM says go 4wd low, run motor for 30 secs - or some amount of time that is long enough plus some more time to be safe that it gets there - and then the worm gear hits the stop and the motor just stalls for the remained of the "time". When you hit the switch to go 2wd, PCM does same thing but in reverse. For 4wd high, the middle position, the PCM would then just use the sensor position to stop the motor travel. The traces on the printed circuit board seem to support this theory.

Now the stop screw head has a plastic bushing around it. Since mine was busted up it was difficult to measure. I replaced it with a piece of polyurethane 1/4" fuel line that gave it a nominal 3/8" final outer diameter. Looked to be close to the original design.

Although dirty contacts, spent brushes, bad windings...could all stop the 4wd from properly engaging, I think the key problem with this entire 4WD lack of engagement is that when this plastic bushing goes away, the motor is driven a little further than it is supposed to. Then the sensor tabs come off the traces on the printed circuit board. Next time you hit 4wd, the PCM does nothing because it has no reference point - doesn't know where the motor is. The program is probably written that if no reference, end - do nothing.

Again, I'm not the Ford engineer that designed this system. But I think what I've described makes sense. Particularly since, the only thing I really changed was adding this stop bushing back. I reassembled everything back to the exact polar alignment where I took it apart - since the gasket ripped on the sensor assembly leaving a peice on each side, I was forced to realign it exactly in the same orientation.

So anyway, I'm getting ahppier and happier with the truck these days. Fixed the 4wd, left lean condition with a new O2 sensor, eliminated engine miss with new wires, straightened out suspension with new poly bushings everywhere (except the upper shackles - poly ones I bought didn't fit).

Only thing left is this 65-75 MPH shake. Goodyear dealer says the tires/rims are fine. I changed the u-joints already. I know I have a bad left side ball joint due to a radical clunk I get at extreme articulations - especially off road. Maybe I'll get to changing that one day and get a surpirse smooth ride at highway speeds.