Converting the Electric Transfer Case Shift Motor to Manual

A while back I mentioned that I had an idea for converting the electric shift motor for the Explorer Transfer Case into a manual drive unit.

Here is a write up with some pictures of my first attempt. Perhaps this can spark some curiosity and engineering efforts amongst the Explorerforum crowd.

Total cost of the parts for this particular build up were limited to the cost of the epoxy kit (about $4.95) and the crank (about $3.00) the rest of the parts were things I had on hand.

So here goes:

The first picture is the parts as I disasembled them and prepared them for the conversion. You can see that I clipped the wires, pushed the drive shaft out of the armature and cut the end of the armature off of the main part to be used later as a bushing. Also pictured is the large washer I used to hold the bearing later - and the piece of emergency brake cable that I used as a driveshaft. The shaft will drive right out of the armature with some "gentle" persuasion with a Ford wrench (hammer) and a punch.



The second photo is the driveshaft, along with the washer, the bushing I made from the place where the brushes ran on the armature, and the top cap, which holds a bearing inside of a spring clip.



The third picture is a close up of the end cap with the bearing in place. I broke off the little teeth that hold it in. The clip breaks easily by prying the teeth off of it (I could not save mine). {sorry about the fuzzy picture}



The fourth photo shows the partially assembled drive shaft for the motor with the large washer in place and the bearing and bushing in place. These need to be used to hold the shaft into the worm gear to keep it from walking out when it turns against the force of rotation. I let the bearing find its own home by pressing it onto the shaft, then pressing the shaft into the worm drive housing - and allowing everything to align where it needed to be.



The fifth picture shows the driveshaft sitting inside the worm gear housing - with the bearing and washer in place. I ground two of the edges of the washer for case scew clearance (the through screws that hold the end caps on the motor case). I also countersunk the inside hole of the washer a bit to give the bearing a positive place to ride (note, I'm calling it a bearing - it is just a bushing in actuality, and it is fixed to the shaft and just rides on the washer. I lubed it with lithium grease throughhout).



The sixth picture shows an end view of the drive shaft assembly with the washer relieved for screw clearance. As you can see - no rocket science here - this is a rough draft to see if it will work.



The seventh photo is the adaptor that I made to fit both the drive shaft and the cable that drives it. I cut a section out of a soft 1/2" carriage bolt, drilled it all the way through with the size that fit my cable, then half way through with a "Q" (letter drill bit - perfect press fit!) for the worm gear drive shaft. I was going to tap it for set screws, but the adaptor was too thin, so I pinned it instead by drilling it for some small nails I had laying around, then drive the nails in through the adaptor, cut off the ends, and hammered them like a rivet to set them in place. It is a very secure drive system that is adaptable to almost any size shafts.



The next picture shows everything assembled and ready for final testing. Note the pins for the adaptor in this shot.



The ninth picture shows how I secured the end of the drive cable into the end cap of the motor with epoxy. I used JB Weld and let it set up over night. I also took some of the epoxy and sealed up the holes where the wires came through the case housing.



The tenth picture shows the assembled unit with the crank and locating washer in place. I took advantage of the fact one end of the emergency brake cable had a metal fitting in place where it went into the bracket that held it on the donor vehicle. I used another of the large washers (which just happened to fit perfectly) - tacked it in place with the wire feed (epoxy would work perfectly) and also drilled it to mount it inside the cab somewhere. I also installed a window crank with a set screw (puchased at Lowes). I used the ball that came on the end of the cable to attach the crank by grinding it to size (my kid spun the cable while I held it to the grinder to keep it round). I then just slid it into the crank and assembled everything.



The final step is to install it on the truck - but you'll have to wait a few days for that. I am going to drill through the firewall and run the cable to the footwell on my left side near the emergency brake and attach it with a bracket under the e-brake handle. It should be out of the way and yet be accesable for shifting.

It takes a number of cranks to get it to turn enough to engage 4-hi and 4-low, but it does it - and the cost was minimal.

After this first go round, I might consider a better drive cable for another version... The e-brake cable was never designed to spin and there are likely better systems out there. I may just pop for the few bucks it takes for one of those cable drill drives - and use that instead for a smoother turning action. I am also thinking about anchoring the bearing in a more postive way, but so far it seems to work.

So, there you go...

can you feel it click it the detents? if not how do you tell when its fully engaged? how much play/twist is in the shaft? have you thought about using the flex-shaft from a gas weedwacker?

Yes, you can feel it click into the detents - just as when you shift them manually - plus you can count the twists and repeat if you like. Of course - 4 lo is all the way one way and 2 hi the other - it is 4 hi that gives any placement issue at all.

I am currently searching for an alternative cable as the e-brake cable is not at all satisfactory. It binds somewhat causing undue cranking pressures - but the idea is sound, and easy to do with the right cable.

Perhaps there might be a way to incorperate the contact switch back into the assembly, so the dash would display what range you are in.

Though this might confuse the computer, worth a shot though.

Another idea, is to use a drive cable (such as the weed wacker cable) or a speedometer cable. An E-brake cable is not designed to be used as a rotating cable.

Good idea though.

2nd post in the forum

Guy, I searched and found the pics Rick took of the shift mechanism on the McNeil Explorer at Truckhaven the other year.
http://www.explorerforum.com/data/showphoto.php?photo=8367&sort=1&cat=500&page=2
T-case hookup, very basic. They welded a bolt onto the shaft!

Here's the knob you turn, mounted between the seats.
http://www.explorerforum.com/data/showphoto.php?photo=8368&sort=1&cat=500&page=2
This 'system' is so basic it's almost primitive, but it works great, and there's almost nothing that can break.

Flyswat said:

Perhaps there might be a way to incorperate the contact switch back into the assembly, so the dash would display what range you are in.

Though this might confuse the computer, worth a shot though.

Another idea, is to use a drive cable (such as the weed wacker cable) or a speedometer cable. An E-brake cable is not designed to be used as a rotating cable.

Good idea though.

2nd post in the forum

Click to expand...

I have the contact switch in place, but my shift controller computer is out, so it doesn't work on my truck anyway. :thumbdwn:

It might work on someone else's truck if your t-case controller works...




Thanks for digging up the pictures of the "simple system".

I like the idea. I can see why you are looking at a different cable. Here e-brake cable is good for push-pull action (like a clutch cable), it wasn't meant for transmitting torque.

I know that there are flexible shafts made to hook up to your drill press, Dremel, etc., (so you can have the rotating tool in hand without the motor also in your hand) that might be what you are looking for. They come in different thicknesses for different torque requirements, and at first you might think 'make it beefy' but the thicker it is, the larger diameter the bends have to be. Besides, you still have the worm-gear attachment so you don't need a huge amount of torque capacity.

I'm not suggesting getting this, just showing an example of the type of cable that I was thinking would work better for you:
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=40432

Weed whacker cable.....that's the same type of cable. Maybe you can find something really cheap in a pawn shop (or garbage).

Since you did this in a way that keeps the worm gear in it, you still have the sensor plate. Since you still have this piece, you could hook up some LEDs to tell you which gear you are in. I think three LEDs (2H, 4H, 4L) would be relatively simple to wire up. Let me know if you want to 'explore' this option further.

Brain,
Thanks - I am just trying to find a long enough cable (needs to be at least 3 feet if you want options in routing - and no kinks or binds) that I can afford. If it runs too much money I could just fix the electrics...

I'd like to see what happens if the sensors were hooked up - it would take a couple of minutes of bench testing to figure out which wires send the signal to the factory lights - and to route a power wire to feed them.

Am I wrong, of isn't that the function of the stand alone sensor (brown wire)?

We're dealing with the BW4404 t-case right? How are the internals of that different than the internals of the BW1354? I thought the brown wire mod simply prevent the modulated signal from reaching the t-case and activating it (therefore the ability to have 2 Lo).

Bronco638 said:

We're dealing with the BW4404 t-case right? How are the internals of that different than the internals of the BW1354? I thought the brown wire mod simply prevent the modulated signal from reaching the t-case and activating it (therefore the ability to have 2 Lo).

Click to expand...

Different brown wire... I'm referring to the one that goes to the sensor on the back of the T-case - not the one under the seat on the 2nd/3rd gens that engages the selec-trac feature...

Check out the "rebuild your shift motor" thread to see which wire I'm talking about... It's the one that has to come out of the plug in order to take the shift motor off of the T-case.

My mod will work on either t-case - but it will make the later varieties into manual shift only - I don't know what will happen to the "auto" feature.

That was an awsome idea, I was also thinking about doing something like that after I saw the McNiel X also, but at least you put it into motion, let us know what cable you do find that worked good enough.


Till then I'll keep using my 1/2" ratchet and custom tool:









Great Job!





Jeff - :navajo:

Posting for updates

SVO, what's the deal on that custom tool? Does the bottom socket fit over the T-case shift knob?

It looks like he stripped the driven gear out of the shift motor and just welded a socket on the end of it to turn the three-cornered drive of the T-case.

I'm out shopping around for a better drive cable... Updates sometime next week. What I did works, I just don't like the "stickiness" of the cable.

I'm tempted to go it the easier way and direct drive it instead of driving the shift motor the way I did... Might be the easiest way out... I'm sure that I could figure out a way of modifying the rest of the drive case for my purposes... I'll let you know.

hahahaha ph man this is gonna be good.

Those "snake drive" screwdriver adapters should provide the torque and smoothness you are looking for, I dont think a speedo cable will be able to turn the sucker, unless you retain the worm gear like you did GLFredrick.....

Where does this mount in the truck?

I'm still confused as to how this is better than switching to a manual 1354. Doesn't the magnetic clutch in the t-case come into play somehow? OR, is this a way to get a '1354' without having to actually do the swap?

I'm doing mine on a 1st gen...

Saves the huge bucks over purchasing a manual case.

Seeing as how they are identical inside - and the shift linkage is made of unobtainium - this is a great way to get manual without paying for it.

As I said above - I don't know what it will do for the auto-track models.

How about some pics of it mounted and of how it works in the interior. I would have thought that it would have required more "torque" to turn it. I'm a Boilermaker, but I work with a bunch of fabricators I'll see if they can come up with something. This is great since I still havn't figured out why mine wont work after rebuilding it twice(checked both times w/battery) and checked the wiring(per someones thread).

I've seen some kits for chevys that seem pretty simple before like this, can't remember where.

If you make it like I did, by driving the worm gear, it takes very little torque to turn it over. Those motors are not all that powerful - they just make the process faster.

As far as mounting it on the truck - the motor fits just like it did in stock condition - (sorry no pics - too much mud under there right now - went out wheeling with it and it is a foot thick and it's been too cold to get all wet getting it cleaned up). The cable extends right out the end of the motor - and points towards the driver's side door. For now, I just have the end of the cable stick up under the hood as I haven't arrived at the final product yet. When I get it the way I want it, I will either run it through the firewall right near the E-brake cable and use an angle braket in the footwell below the E-brake release - or I'll bring it in the center of the tranny tunnel and into the interior that way. It will mostly depend on the flexibility of the final driveshaft that I end up using - and the clearance between the tranny and the sheet metal for the floor pan.

On mine, there is tons of room that way - I have a 3" body lift - but I want to see how it will be for someone else that doesn't have that option.

I'll let you know and post a few pics when I get it figured out.

I've now found a place locally that will actually build me a custom cable of any length and ends I want - and I'm going to get one made like that. They cost around $30 - which is still reasonable for a manual conversion.