46 Power Wagon Restoration pt. 2

[JStinson]

This is really interesting to see. Thanks for posting!

[cj7ox]

Desoto, your truck is looking good! I love the attention to detail and am thoroughly enjoying this thread1

Sean

[Desoto61]

Repeat and rinse

Tore down the rear differential. This one had been rebuilt once before, apparently when something broke as there's signs of damage inside the case. Nothing serious but some scratches in the housing and not all the bearings are Timken like the front diff.

Luckily this one went faster partly because it's been apart before, and partly because I'm replacing the differential carrier with an ARB, a new ring and pinion, and all new bearings; so I only need to save the 3rd member housing and associated parts. Otherwise it gets the same treatment as the front.

Front axle housing is at the media blasters along with the tie rod. Front differential assembly was rebuilt by Charles Talbert and should be on its way back any day now. Rear wheel hubs have been converted and are also on their way back, then the front hubs will go out.

New ring and pinion sets should be here any day then I can start the rebuild(s). Otherwise I continue to clean parts and organize them and the garage so they can be primed/painted or powder coated.

Still trying to track down new springs as well.

[Desoto61]

Calm before the storm

After a bit of a fight with FedEx I got the ring and pinion sets from Vintage Vehicles.

The plan is to rebuld the front diff first since it sees less use so it will be better to learn on. Plus it's a stock rebuild so it eliminates any of the extra complexity of the air-locker.

In researching the build I came across this thread that discussed the ring gear bolts. So never one to turn away good advice I ordered the bolts and lock nuts as recommended.

Since I had the ARB ready and the front diff is on its way back from Charles I went ahead and mounted the rear ring gear on the ARB per the included instructions. Then modified the new fasteners and installed them with the lock nuts and some red lock tight.

After all the nuts are installed and torqued to spec I installed the air ring per the directions, it's a very tight fit and you can't twist the o-rings so it was a slow proceedure.

[Desoto61]

Then the bearings get pressed onto each end. The ARB comes with very good instructions that look like something we write for nuclear work. Each block is specific and gets a check-block next to it when completed. There are quite a few pictures throughout as well.

Next they instruct you to drill and tap a hole in the casing for the air line. Took some searching to find a 1/4" pipe tap but got the last one at the 4th store I tried. Naturally you need to use some rags to plug holes and make sure no metal shavings get left in the housing.

Then I flipped over the housing and installed the outer pinion cone and the race retaining nut and tightened down the lock screw.

[Charles Talbert]

A fight with Fed-Ex, that sounds familiar, but that's another story.

You should have your stuff from us back today via UPS.

You will also find the set up using the ARB to be much easier than setting up the original carrier. The ARB is CNC precision machined, whereas the original is far from being that precise. When doing a total rebuild, it is possible to save 2-3 hours when using an ARB instead of the original. The simple truth is this; even with the relatively high initial cost of the ARB, saves valuable time during set up, a much more precise set up is easily possible, and it will last far longer if you keep clean premium quality oil in the unit.

The bottom line is this, installing ARB is the smart move, do it once, do it right, maintain the oil and seals well, you are set for life.

[Desoto61]

A fight with Fed-Ex, that sounds familiar, but that's another story.

You should have your stuff from us back today via UPS.

You will also find the set up using the ARB to be much easier than setting up the original carrier. The ARB is CNC precision machined, whereas the original is far from being that precise. When doing a total rebuild, it is possible to save 2-3 hours when using an ARB instead of the original. The simple truth is this; even with the relatively high initial cost of the ARB, saves valuable time during set up, a much more precise set up is easily possible, and it will last far longer if you keep clean premium quality oil in the unit.

The bottom line is this, installing ARB is the smart move, do it once, do it right, maintain the oil and seals well, you are set for life.

Yes, I've had a bunch of people say how much they like FedEx but it's been a lot more time consuming than dealing with UPS.

I doubt I'll notice any time difference but I'm not charging anyone by the hour, so I'm much more interested in tripple and quadruple checking my steps and trying not to get ahead of myself, but the ARB is a nice unit.

Yes I've got a cabinet full of Royal Purple gear lube ready to go in. With all the time and money in these axles the extra cost of the full synthetic is cheap insurance.

[Desoto61]

So the last batch of pictures has me turning to the pinion gears. The instructions with the new set said to use some abrasive cloth to remove the coating to allow the outer pinion bearings and the yoke to slide on and off without the use of tools to aid in setup. Once I had that done I went ahead and installed the new inner pinion bearing using a piece of pipe and the lug nut socket in the arbor press.

On the front axle I had planned to re-use the pinion bearings due to their high cost and low use. They all looked good so I managed to get the bearing press plate for the pinion and remove the existing bearing.

[Charles Talbert]

Yes, I've had a bunch of people say how much they like FedEx but it's been a lot more time consuming than dealing with UPS.

I doubt I'll notice any time difference but I'm not charging anyone by the hour, so I'm much more interested in tripple and quadruple checking my steps and trying not to get ahead of myself, but the ARB is a nice unit.

Yes I've got a cabinet full of Royal Purple gear lube ready to go in. With all the time and money in these axles the extra cost of the full synthetic is cheap insurance.

I too like Fed-Ex service better than UPS. It's when you have an issue of some sort that you need to talk about with someone, good luck with that. I'd just as soon try to contact the president to ask what time it is, couldn't be any harder. Truthfully though, in a similar situation, dealing with UPS may be just as difficult, haven't had that to come up with them.

[Desoto61]

Pinion problems

Ordered a spacer set for the pinion setup from Midwest Military. The paperwork provided with the pinion says that the running torque for proper pre-load should be 15 in. lbs on used bearings.

Procedure states to install the shim between the outer double bearings install the pinion and tighten the nut to 200 ft. lbs. then rotate the assembly a few times and check the running torque.

To tighten the pinion to spec I made a tool to hold the pinion while I torqued it. I cut a piece of 3/16" steel plate to fit over the input yoke and welded a long piece of angle iron to it.

The stock spacer was too thick, so I tried the thinnest spacer in the kit (0.178") and the bearing pre-load was still too light. Double checked I had the bearings in correctly as some have an orientation but I could not find any identifying marks on the race. The bearings have an I and a L etched but not sure what those mean. Swapping them didn't seem to change much.

So using the shim set I got for the t-case work I played with some other thicknesses and ended up getting the right preload with a stack measuring 0.168".

[Charles Talbert]

I if recall, you are changing to 4.89 gearing. The specs in the book will not work for that gearing, so it will be necessary to do what you have done to get it right. Be careful with that torque on the pinion nut, it is really critical that you don't over do it. 200 ft. lbs. is right at the top of what it will stand without damage.

[Desoto61]

I if recall, you are changing to 4.89 gearing. The specs in the book will not work for that gearing, so it will be necessary to do what you have done to get it right. Be careful with that torque on the pinion nut, it is really critical that you don't over do it. 200 ft. lbs. is right at the top of what it will stand without damage.

Thanks, I was hoping you'd chime in. Yes, I'm installing 4.89 gearing. The instructions and specs I'm using for the pinion nut and bearing pre-load are the ones that came with the ring and pinion sets from Veteran Vehicles.

Would you suggest backing off the nut torque 10 or 20 ft. lbs then, or just go with 200 as the paperwork suggests?

[Charles Talbert]

Thanks, I was hoping you'd chime in. Yes, I'm installing 4.89 gearing. The instructions and specs I'm using for the pinion nut and bearing pre-load are the ones that came with the ring and pinion sets from Veteran Vehicles.

Would you suggest backing off the nut torque 10 or 20 ft. lbs then, or just go with 200 as the paperwork suggests?

That's your call, I usually pull that nut to 160#. Years ago when the shaft had the hole drilled for the installation of a castle nut with cotter key, (all the early 4.89's had that hole, but it has since changed) I actually had the end pop off of 2 shafts. The shafts without the cotter hole are certainly substantially stronger, but I always remember what happened every time I install one.

I always install new bearings also when I do gears, it's impossible to tell how much wear a bearing may have on it and I just don't feel good about reusing old ones unless I knew their history for sure. A bearing gets used to where and how it has run for years, develops a wear pattern. When you do a new installation, all that changes, you can never tell how a bearing assembly may react if you take it out of sync and make changes. They are actually a lot like people, they don't like change. As you know these gears are premium priced, I'd hate to destroy a set because of a bearing failure. That is very likely to happen if a bearing went down. Just my opinion, food for thought, and once again your call.

[Desoto61]

With the pinion in I installed the ring gear and differential assembly and started through the military manual on setting backlash and bearing pre-load.

I had to work out some logistics for measuring case spread as I don't have a micrometer large enough to go between the bearing caps. On suggestion I made up a set of L-shaped tabs that could be bolted to the bearing caps and measured with a set of calipers. It took a few tries to work out the right method to get an acurate measurement as the added height of the uprights exxagerate the case spread measurement. Some math helped put everything back into perspective.

With everthing where I think it should be I added some gear marking compound and ran the unit around both directions to see what I had. I think it looks good as far as I can tell.

[Charles Talbert]

Looks good

That tooth contact pattern is very near perfect. You want the pattern to favor the toe of the tooth when turned by hand on the bench as the picture shows well; the contact area will move on upwards on the ring gear teeth when it is operated under a load. Based on what I can see, you have a good set up that should run great.