Dust Boot Replacement

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Chuck W.
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Dust Boot Replacement

Post by Chuck W. » Fri Jan 09, 2009 9:44 pm

While I'm replacing the wheel seals and dust boots on Todd's mule, I thought I'd try to document the process, so here goes. I'll spread it out over several posts.

PART ONE
Removing the hubs.

First thing is to get the mule up on stands and remove the wheel.
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Sounds simple, remove the 5 lug nuts......but sometimes the wheel is stuck to the hub and it may take lots of force with a dead-blow hammer on the back of the tire.
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Next, remove the two 1/8" plugs. They should be brass with a straight screwdriver slot or an allen socket, but no telling what you might find. Whatever you have, they both must be removed.
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Now the fun part, use a long punch to remove the lock pin. It is suppose to be a 9/64" x 1 1/4" spring pin. No telling what you will find, and you may have to rotate the lifting ring to find the hole with the locking pin in it.
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In this case it was a cut-off nail. That's about normal, that's what I find in about 9 out of 10 hubs! This does not work, because the nail will slide down into the hole in the lifting ring and then the ring won't turn....then somebody gets a long pry bar.....and you know the rest!
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Once you have removed the spring pin, nail, wire, stick, whatever you find, you are ready to remove the retaining nut from the axle. DON'T try to remove the nut until you have removed the locking pin or know for certain that there is nothing locking the axle nut to the axle. A broken piece of spring pin can really screw-up the threads inside the nut (experience talking!)
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Once the nut is off, you can slip the hub off the axle.
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This is a good time to pry the lifting ring off the hub and clean everything up and install new O-ring seals. Use grease on the O-rings when you go back together to keep everything free. Don't leave the seals out, or dirt and water will enter your hubs.
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If you are only changing the hub seals, use a seal puller to remove the old seals and install new ones.
You would follow these same basic steps to replace the hub seals on the non-steer axle of a 2WS mule.
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If you are changing the dust boot, stay tuned for the next post.
Last edited by Chuck W. on Sun Jan 18, 2009 1:52 pm, edited 7 times in total.

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Post by Chuck W. » Fri Jan 09, 2009 10:18 pm

PART TWO
Removing the knuckles.

You're down to the hub seals, but it's a steer axle and you you need to replace the dust boot, too.

Next step is to remove the tie rod from the knuckle housing. Remove the cotter pin from the nut and then remove the nut.
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Use a pickle fork to remove the tie rod from the housing. This is where the right tools will pay off. If you damage the tie rod end, they are very expensive!
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Use a screwdriver to remove the screw and nut from the retaining band on the outer end of the dust boot.
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Remove the band completely. Don't forget to put the nut back on the screw for safekeeping!
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Use a screwdriver to pry the outer end of the rubber boot out of the slot in the knuckle housing. Make sure you have a catch pan, there should be oil here.
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Now remove the nuts holding the top and bottom kingpins in the knuckle housing. There should be sheetmetal locks under the nuts, but they were missing on this mule.
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As you remove the kingpins, the knuckle will probably fall off, watch it and keep everything together. Make sure you know which kingpin is top and bottom, and keep the shims with each kingpin.
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Keep the top and bottom roller bearing with the correct top and bottom kingpin.
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Where did that bottom bearing go? There it is, in the catch pan!
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Now you can slip the axle out. Don't loose the spacer on the inner axle, and be careful, sometimes worn axle joints will come apart when you pull them out.
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When you roll back the rubber dust boot, you will see the retaining wire that holds the boot into the groove in the axle housing, cut the wire and remove it completely.
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Use a screwdriver to pry the rubber boot out of the groove in the axle housing and simply pull the old dust boot over the axle housing.
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Clean, clean, clean; get everything clean and inspect all the bearings and cups. These axles were not too bad, but sometimes you find them full of grease instead of gear oil and they are a mess to clean up. By the way, if you are doing more than one wheel at a time, make sure to keep everything labled so that the right parts go back on the correct axle. If you get the knuckle housings on the wrong side, you'll have a problem!
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I'm going to take a few days off and then we'll start putting this back together.
Last edited by Chuck W. on Sun Jan 18, 2009 1:52 pm, edited 4 times in total.

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Rod
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Post by Rod » Sat Jan 10, 2009 7:53 am

Chuck,

Most excellent documentation. Like you said we don't need to mix up the parts from each side. I usually only pull one side down at a time.
I want to live life, til the day I die.

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Post by edisworking » Sat Jan 10, 2009 3:15 pm

Great job
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Post by atavuss » Sat Jan 10, 2009 6:32 pm

most excellent post Chuck! you make it look easy!
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Post by carolina-mule » Mon Jan 12, 2009 2:16 pm

sounds like the MULE DOC might have preformed this operation quite a few times. let me say i appreciate all you do for this hobby. thats what i call an excellent tutorial. cant wait until you finish it up.
c-m
ps: next time you do a clutch, would you document it and put it on the forum some time. thanks again!
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Post by Chuck W. » Fri Jan 16, 2009 5:08 pm

It was 13 degrees yesterday, and for Alabama, that's COLD! So, needless to say, the dust boot replacement project is on hold until we get back to our normal winter temperature of 50-60!
Chuck

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Post by Chuck W. » Sun Jan 18, 2009 1:49 pm

PART THREE
Adjusting the kingpin bearing preload.

Looks like the weather is easing up some, so maybe I can get back to work on Todd's mule. One thing I need to do first is adjust the bearing preload on the kingpins.

Normally, if you don't change any of the bearings, races or kingpins, and you keep everything together in the same order as they were removed, you can simply reinstall everything and you should have the same bearing preload as before.

If you did change things, or mixed up the shims, or just want to make sure things are right, you'll need to use this adjustment procedure.

In this case, somebody installed home-made paper gaskets unter the kingpins, so I want to start from scratch and readjust everything. We'll fix the potential for oil leaks when we go back together, and we won't use gaskets!

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Shim sets are available from mule parts suppliers, and include .003", .005", .010" and .030" shims. I like to start with one of each on the top and bottom kingpin.

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I install the knuckle, bearings, shims and kingpins dry, without the axles and dust boots. The book says you need 3 1/2 lbs of force with a spring gauge to move the knuckle. I just do it by feel. With a full shim set on the top and bottom kingpin, the knuckle will generally be way too loose and will even have up-and-down movement.
You will have to remove each kingpin and adjust the number of shims several times until you get the proper amount of "drag" when you turn the knuckle. Try to remove and/or add the same number of shims to the top and bottom kingpins.

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In this case, it required one .030", one .010" and one .003" on the top kingpin and one .030", one .010" and one .005" on the bottom to get the slight amount of turning resistance I was looking for.

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Keep everything together until you are ready to go back together,

Some final cleaning, pack the bearings and axle joints with grease, and we'll be ready to put the knuckles back together with new dust boots and seals.
Stay tuned....

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Post by Chuck W. » Wed Jan 21, 2009 3:45 pm

PART FOUR
Putting it all back together.

Everything is clean and we're ready to go back together. I use a little black silicone sealant on the seal groove on the axle. You can also see that I've greased the kingpin bearing cups.
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Next, work the new boot over the axle until it seats in the groove. If it's warm, you can lay the new boot in the sunshine for a while and it will be easier to install. It's 40 degrees here today, so I had to be careful and work slowly. Once it's in the groove, rotate the boot to spread the sealant and work it into the groove.
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I've tried several types of tie wire, but I like this stuff that Rod gave me, it's some type of telephone lacing wire. It's flexible and does not break as easily as some I've used. It's also galvinized so it won't rust. I tred some stainless steel wire I found at Ace, and it was OK, but it broke real easy when I was twisting it tight.
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Wrap the wire around the boot, making sure to keep it just behind the lip. When the wire is tigntened, it will seat the boot into the groove in the axle housing. Don't twist it too tight or the wire will cut into the rubber boot. Just tight enough so the boot won't turn on the axle housing.
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I put the twisted part at the top, where the boot does not flex as much.
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And be careful to tuck the end down where it can't damage the boot.
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Next, install the axle. Don't forget the spacer on the inner axle. I have packed the joint with grease.
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To keep oil from leaking around the kingpin shims, I coat each one with a spray Copper Cote sealant compound.
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Pack the kingpin bearings with grease just like a wheel bearing and then install the bearings, hub and kingpins in the reverse order that you removed them. You can see that I've already installed the new hub seal in the knuckle housing.
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Again, a little black silican sealer in the groove on the knuckle.
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And use your hands to roll the boot into place in the groove on the knuckle. If you use a screwdriver, be careful not to poke a hole in the boot!
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Install the band on the boot at the knuckle, make sure you have the band on the rubber and not on the edge of the knuckle housing, and tighten. Again, don't overtighten. Keep the screw and nut near the top of the knuckle where the boot does not flex as much.
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Install the tierod with the nut and cotter pin.
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I like to put just a little sealant on the axle splines before I install the hub.
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Install the hub onto the axle. You will have to work it gently until is slides all the way into the hub bearing. You can see that I've installed a new seal on the hub and greased it.
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Install the lifting ring onto the hub, use plenty of grease or anti-seeze compound.
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And install the axle nut.
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I snug the nut down, then use my small punch to align the holes in the nut and the axle.
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The lock pin is a 9/64" x 1 1/4" spring pin.
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I use my large pinch to drive the pin flush with the nut.
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Then switch back to the smaller punch to drive the pin slightly below the nut until the lifting shackle will turn freely.
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Install the two brass plugs into the lifting shackle.
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Service the knuckle with SAE 90 wt as per LO 9-2320-246-12, install the wheel and tire and you're ready to roll.
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THE END
I hope this helped you understand how easy it is to install new dust boots and hub seals. I will be glad to answer questions or help if I can.

Now I have to turn the mule around and do the other axle, and I think there will be some surprises inside....this is usually not a good sign:
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update: The front axle is finished and I didn't find any problems. The knock that I heard when moving the mule turned out to be loose lug nuts that were letting the wheel rock back-and-fourth on the studs!
Last edited by Chuck W. on Sat Jan 24, 2009 5:29 pm, edited 2 times in total.

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Post by PBragg » Wed Jan 21, 2009 6:26 pm

Chuck,
I must say that is one of the best tutorials I've ever seen.
Bravo! Great job and thanks for taking the time and effort. I'm sure there are many "Mule Skinners" out there that will use this.
Phil Bragg

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Post by mulezilla » Wed Jan 21, 2009 10:24 pm

Great tutorial Chuck and great timing to as right after I get the parts I ordered to finish installing my new motor I was going to change boots and seals on the drop axels. Got the new style puller for the shift shafts seals today and tried it out and it worked like a charm I had all 6 of them out in less than 20 min.............................Ron
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Chuck W.
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Post by Chuck W. » Sat Jan 24, 2009 5:16 pm

Just a few followup comments:

1. As I look at the photos, I notice that I don't have the dust boot retaining band positioned correctly on the back of the knuckle, the screw and nut should be directly behind the top king pin. This will prevent possible damage to the boot by the sharp edges on the band.

2. Some of the dust boot retaining bands seem to have a slight taper, and the narrow part of the band should be to the outside...in other words, if the band tries to slip off the boot to the inside when you tighten it up, turn the band around and see if it fits better.

3. Sometimes the inside edge of the knuckle where the axle seal goes will get a knick or two, and can damage the new seal when you try to install it. I almost always make a few passes around the lip with a die grinder and stone after the old seal is removed and before I install the new seal. This puts a little bevel on the seal bore and makes it much easier to start the new seal....doesn't take much. This is especially true on the rear housings on a 2WS mule for some reason.

One person asked about the long punches shown in the photos. These are great for removing and installing the axle nut retaining pins. This is a cheap-o, made in India set, that I found at the bargan tool place. I've looked but I have never found another set!

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Re: Dust Boot Replacement

Post by clinto » Wed Dec 23, 2009 4:51 am

Thanks for doing these writeups, Chuck, they are awesome!
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Re: Dust Boot Replacement

Post by Chuck W. » Mon Feb 01, 2010 5:56 pm

I finally found a new source for the long pin punch that I use to remove and install the roll pin in the axles.....set of 5 different size punches, $10.00 plus shipping...if anybody's interested.
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Re: Dust Boot Replacement

Post by WLEIT » Fri Aug 13, 2010 5:47 am

Hello, trying to get my mule up to speed... am now attempting to take off the tires for a dust boot replacement. All the nuts are frozen with rust from neglect. I managed to get one off but are their any tips one getting this crap off! And how do you get the little brass fittings over the roll pins off if their crap, too? Oh, and does the lifting ring rotate to get at the nut or is it fixed? Thanks guys, I'm really in a pickle here.

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