D-18 Transfer Case Assembly

Our friend Doug H wrote this pictorial how to for this old Willys back in 2010. He rebuilt the transfer case from his 3B and took the pictures as he did it, adding notes as he went. It was such a good how to that when we discovered it here we asked Doug if he minded sharing it with the 3A population. He willingy donated the following tech article to us here. (We didn't even have to bribe him too much!) Doug did emphasize it is only his experience with his case, and everyone looking to rebuild theirs should also refer to the factory books and Rick Stivers rebuild guide too. Model 18 Rebuild Just relying on this page alone may result in less than optimal results. And, as always, use proper safety procedures and precautions, wear safety equipment like face shields and safety glasses when appropriate, and do this on your kitchen table ONLY when your significant other is at the relatives. The 3A page only presents this information for your trained eyes and mind to digest, and any use of the information contained within the 3A pages is completely at your own risk, as it should be. A note about parts: Do not rely on price alone to judge which part to buy, especially when purchasing repair pieces for your gearboxes. NOS Willys parts are best, as are older NORS (New Old Replacement Stock) parts made in the USA. Imported parts have had a reputation for early failures and questionable metallurgy. Rick mentions a way to test the replacement shafts in the home shop in his guide.


Made by Doug H

Jan 4 10 10:43 PM

Okay, here we go. Once again, I used Rick Stiver's guide to put this puppy back together. I got the rebuild kit from Walck's. Still have some E-brake parts to order, so this post will be a work in progress for awhile. I just need to start putting pics up so I don't forget too much. This will be VERY picture intensive. This is intended to be used in conjunction with Rick's guide which contains important information that I did not include in this topic.

Here we got all of the major pieces of the case cleaned and painted and the small parts kit:

image

Here are the speedo gear, sleeve and rear bearing cap:

image

Install the speedo gear and sleeve. Use a bit of sealant on the sleeve but make sure not to get any on the gear:

image

Bearing, snap ring and front cap:

<image

Bearing and snap ring installed in front cap. I used the brass hammer and drift to drive the bearing in place. You have to drive it in evenly all around. Watch your eyes if that snap ring decides to fly when you're installing it:

image

Here we install the output clutch shaft into the bearing that you just installed:

image

Next, we'll be installing the short shift fork shaft and it's associated shift fork:

image

Here's a shot of the shift rod and fork installed. The set screw is tightened and safety wired in place. Last thing you want is for that set screw to come loose sometime in the next 50 years and get all tangled up in those gears     The wire is approximately the size of coat hangar wire and I used pretty stiff wire; it was stiff enough that I wasn't able to use my safety wire pliers to make a professional looking twist. But, it doesn't look too much worse than it did when I took it apart:

image

Next in line is the output clutch gear:

image

The output clutch gear in place on the shift fork and everything tucked away neatly in place in the front bearing cap:

image

Here is the longer shifter rod and it's fork. In the next step, we will be installing both into the case:

image

Shift rod and fork installed in case and set screw tightened:

image

And, this set screw should be safety wired as well:

image

Now, we install the cone bearing on the rear of the output shaft:

image

Rick recommends using the old bearing on top of the new one so you are not driving directly on the new bearing. It is pretty clear in this picture:

image

Next, put the sliding gear into the case; it goes onto the shift fork:

image

Now put the output shaft gear into the case:

image

Slide the output shaft through the case and gears from the rear:

image

Output shaft installed:

image

Slide the thrust washer onto the front of the output shaft:

image

Next, slide the snap ring onto the front of the output shaft:

image

Here is a shot with the snap ring full installed into the groove in the shaft:

image

Now, we can drive the front bearing onto the output shaft:

image

The front bearing cup:

image

If you get the bearing cup tapped in flush with the case, that is good enough. When you install the front cap, it will seat the cup to the proper depth:

image

Now we TEMPORARILY install the front cap. I put on the gasket (without sealant) because we will be checking end play soon. The interlock pin does not need to be installed in the front cap at this point; it will be coming back off, so you can install the interlock at that point:

image

Next we will install the rear bearing cup; only tap in a little bit:

image

Rear cup installed:

image

Now here we go with the shims. I absolutely hated this part. You want to begin with a THICKER pack of bearing than you actually need. If you use too thin of a pack, you will have no end play and will have to remove the front cap to tap the main shaft towards the front. Believe me, I had to do it two or three times    I actually used all of the shims that came in the pack plus a thick one that had been on previously. Rick's guide wants you to start with a shim pack .060"

image

Here is how the shims go on there:

image

Once you have a shim pack of the correct size (use Rick's guide to figure that out) to give you the correct end play, you'll remove the rear cap and clean up the shims. Spray both sides of each shim with the Permatex copper gasket sealant or something similar:

image

Spray and allow to become tacky or follow directions on what ever you use:

image

Before installing the shims and rear cap permanently, slide the speedo gear onto the rear of the main shaft:

image

Now, install the shim pack and rear cap. Don't forget to torque to proper specs - no cheating and using your "calibrated fingers"  

image

Remove the front cap (hopefully the only time you had to remove it during the process):

image

Here is a shot of the front cap all the way removed:

image

This picture shows the hole between the two shift rod holes in the front cap. This is where your interlock pin goes. You can drop it right through where the poppet ball, spring and plug go:

image

The interlock pin. Keeps you from putting your rig into 2-Low. I chose to put mine back in; some people leave them out:

image

The two pictures below show the interlock pin in place. The first picture shows the pin protruding into the hole for the shift rod. The rod will NOT go in if the pin is in this position. The second picture shows the interlock pin fully recessed. The position of this pin changes depending on the position of the shift rod.

image

image

I used a piece of tape to mark where the shift rod should be in order for the pin to be fully recessed.

image

Don't forget the gasket and sealant before you put the front cap back on. Tighten the bolts down to 30 foot pounds - no cheating again:

image

Next, I put the shift rail oil seals on:

image

A piece of metal tubing worked great to seat the seals. Might be better off with PVC, but I didn't dent or damage the seals:

image

The tubing fit right over top of the shift rails with no problem:

image

Here the oil seals are fully seated and hopefully won't leak:

image

Okay, now we get to put the roller bearings and washers into the intermediate gear (NOTE: apparently, there are different procedures for the different size intermediate shafts. This shows the 1-1/4" shaft procedure). I used the old intermediate shaft with a bit of grease on it as the dummy shaft:

image

First thing to go in is a washer. I greased everything up to help things together:

image

Now, one set of needle bearings:

image

Next, another washer. Then, I used a screwdriver to push everything down into the gear.

image

Now another set of needle bearings and a last washer:

image

Everything pushed in flush:

image

Install the thrust washers into the case. Grease and an old intermediate shaft or proper size socket helps hold the washers in place:

image

Intermediate gear in place with new intermediate shaft part way installed:

image

Once the shaft is fully seated, I sealed up the front end of the shaft:

image

Here, the locking plate is installed and the rear of the shaft is sealed:

image

Next, we will be installing the poppet spring, ball and cap on both sides of the front bearing cap:

image

This picture shows the poppet cap once it's installed:

image

The front main oil seal will be installed next. Rick recommends the double lipped oil seals - not the ones that come in the kit. Since the main reason that I'm rebuilding this case is due to leaks, I took his advice and ordered two Federal-Mogul oil seals Part number: 473229. To install the oil seals, he recommends the "Vernomatic 5000." After a quick internet search, I discovered what a "Vernomatic 5000" is.

http://www.willystech.com/faqs/Breakout/TransmissionTransfercase.html#VERNO While I'd love to buy a wood lathe, I didn't figure that it was very prudent to go out and buy one at this time. I liked the PVC idea better so I was off to Lowe's after a quick check around the garage. I was going to buy a long piece of PVC and cut it, but when I got there, I noticed the PVC couplers (1-1/2"). They seemed to be just the correct length and were $0.66 each. I picked up two. I guess I will call them the "Doug-O-Matic 100."    

image

I tapped the seal flush with the mallet:

image

Then used the "Doug-O-Matic 100"

image

To fully seat the oil seal:

image

Now, the felt seal goes into the front yoke:

image

Then install the front yoke:

image

I used my impact wrench to install the front nut. I will check the torque once I have the transmission and transfer case together and can "lock" the gears up.

image

Next comes the emergency brake operating lever. Rick's guide says to torque the nut to 20 foot pounds. When I did this, I found that the lever would not move, even with washers on top and bottom. I backed the nut off to the point where I could still insert the cotter pin. The lever moves freely. I guess I will find out if it will work after it's installed:

image

I screwed up at this point and installed the emergency brake backing plate and forgot to put the gasket on. I forgot to get a picture, but the picture below shows the backing plate on. I had to trim out the center part of the gasket from the kit for it to fit. I didn't see anywhere in Rick's guide to put the bottom pan on so I figured that it was a good point to do it.

image

Here is a shot of the bottom pan installed and a little better view of the backing plate so far:

image

While waiting for parts, I built a little dolly to move the whole assembly around easier. Here, the transmission is mounted back on the crossmember and the gasket in place:

image

Ready to bolt the transfer case on:

image

T-90 and D-18 back together again:

image

Install the transfer case mounting bolt:

image

Install gear, washer, nut and cotter pin:

image

Install the rear cover:

image

Here is a shot of the parking brake backing plate:

image

Cam and pin/ tension spring assembly:

image

Adjuster screws installed:

image

About the time that I was ready to install the drum, I discovered a problem. Three of the bolts would have been fine, but the fourth just spun in there. This had some damage before and was "repaired." It needed further repair:

image

Time to bust out the new welder for a test drive:

image

I'm not the best welder ever, but it works:

image

Bolts now fit in and don't spin:

image

Rear yoke installed in drum:

image

This is the INCORRECT routing of your springs. Take your hand away from this set up and it WILL try to bite you.

image

Here is the correct way to install the E brake shoes:

image

Drum in place:

image

Rear yoke nut in place and torqued:

image

Breather installed:

image

Pivot for clutch tube:

image

Finally, shifters installed to test everything out:

image

I guess that finally wraps it up. Nothing left to do but install and test - and pray for no leaks     

Update: I got mine fully installed and filled with oil. I jacked the back wheels off the ground and ran through the gears a little bit. I then drained everything to get rid of any contaminates that may have been left over from the rebuild. No leaks observed yet.

Doug