Steering knuckle boot maintenance questions

[TacticalDoc]

I looked up the TM and did a SS search but still have questions.

(1)....apply adhesive to exposed zipper and fabric. Allow adhesive to sitovernight. What adhesive am I supposed to use? Can you use seal maker?

(2) Discard safety wire (1). Where can you find a replacement for the safety wire? Is it just standard wire?

(3) 5. Lace zipper locks with fine wire near edge of steering knuckle seal (13) and twist together.

(4) How do you fill it with grease? How do you know how much grease to put in it?


I'm sure I'll have more questions but just wanted to ask some questions before starting.




a. Removal
1. Remove four screws (4), lockwashers (3), and seal guard (5) from steering knuckle (2). Discard
lockwashers (3).
2. Remove twelve screws (7), safety wire (1), and retaining plate (6) from steering knuckle (2). Discard
safety wire (1).
3. Pull one side of steering knuckle seal (12) aside to expose inner retaining clamp screw (10).
4. Remove inner retaining clamp screw (10) and spacer (9) from inner retaining clamp (11).
5. Remove seal (12) and inner retaining clamp (11) from steering knuckle (2).
NOTE
Some seals may not have a zipper.
6. Open zipper (or cut to remove seal (12) from axle housing (13).
b. Cleaning and Inspection
1. Clean surface of steering knuckle (2), retaining plate (6), and steering knuckle seal (12) with
cleaning cloth. Ensure there is no dirt or dust is inside steering knuckle (2).
2. Inspect steering knuckle seal (12) for cracks, tears, and damaged zipper Replace if cracked, torn,
or zipper is damaged.
c. Installation
1. Place steering knuckle seal (12) on axle housing (13), with fabric side of zipper facing steering
knuckle (2).
2. Close zipper and apply large amount of adhesive to locks and fabric of zipper. Allow adhesive
to sit overnight.
3. Force inner lip of steering knuckle seal (12) into groove on axle housing (13). Ensure steering
knuckle seal (12) is aligned to holes in steering knuckle (2).
4. Position inner retaining clamp (11) to lip of seal (12) and install clamp screw (10) and spacer (9).
5. Lace zipper locks with fine wire near edge of steering knuckle seal (13) and twist together.
6. Cut off excess zipper and apply adhesive to exposed zipper and fabric. Allow adhesive to sit
overnight.
7. Align seal retaining plate (6) to holes in steering knuckle (2) and install twelve screws (7). Ensure
notches in screw (7) heads are aligned so safety wire (1) can be installed.
8. Thread new safety wire (1) around each screw (7) and tie Off.
9. Install seal guard (5) on steering knuckle (2) with four new lockwashers (3) and screws (4). Tighten
screws (4) 130-170 lb-ft (176-231 N.m).

 

[searls84]

1.) I use RTV to seal the zipper
2.) My knuckle boots have never lasted more than 8 months before rotting out, so I don't even bother with safety wire.
3.) if I recall correctly, the retaining ring keeps the zipper secure.

 

[MtnSnow]

Where did you find replacements and what part number? I have one boot that is ripped at the bottom that I would like to get replaced ASAP.

 

[searls84]

I get mine from Boyce Equipment because it takes 2 days for my order to arrive, but any of the normal military parts places should carry them. Word of advice, keep the stock military boots on as log as you can, the replacements (both silicon ad zipper style) are far inferior and DO NOT hold up very long!

 

[TacticalDoc]

I get mine from Boyce Equipment because it takes 2 days for my order to arrive, but any of the normal military parts places should carry them. Word of advice, keep the stock military boots on as log as you can, the replacements (both silicon ad zipper style) are far inferior and DO NOT hold up very long!

good to know. I was going to replace both but only one is leaking

 

[MtnSnow]

Has anyone had luck at "patching" a tear in a knuckle boot?

 

[73m819]

Has anyone had luck at "patching" a tear in a knuckle boot?

NO

 

[TacticalDoc]

How much grease do you put in it? I take it that you inject it into the grease fitting a the top?

 

[TacticalDoc]

Not much input so far but this is what I'm getting so far

(1)....apply adhesive to exposed zipper and fabric. Allow adhesive to sit overnight. What adhesive am I supposed to use? Can you use seal maker?

Seal maker on the zippers

(2) Discard safety wire (1). Where can you find a replacement for the safety wire? Is it just standard wire?

You don't need this wire because you'll change the boot frequently

(3) 5. Lace zipper locks with fine wire near edge of steering knuckle seal (13) and twist together.

Not sure what this means...can someone explain?

(4) How do you fill it with grease? How do you know how much grease to put in it?

Not sure on how much I should add

Anyone have any other answers???

 

[silverstate55]

I have to change out the driver's side boot on my M931A2; compared to what is required to do this on a Deuce, the 931 is a piece of cake.

(1) Use RTV or seal-maker; all you are trying to do is prevent grease from leaking out through the zipper.

(2) Use safety wire from NAPA (or other auto parts outlet), or galvanized wire from auto parts section in other outlets...before this wire has a chance to break and/or corrode, chances are you'll be replacing the boot before then anyway. All the wire has to do is prevent the bolts from backing out & falling off.

(3) Visualize the zipper becoming 'unzipped' and allowing grease to fly everywhere & dirt/contaminants to get into the steering knuckle grease. Do what you think you need to do to prevent the zipper from 'unzipping' on its own. Heck, you could use a grocery-store twist tie to secure the zipper end from opening on its own.

(4) I've learned this the hard way: only use a little bit of grease, just enough to coat the bearings & moving parts inside. If you use too much, then when you make a tight turn this grease (that does NOT compress, BTW) will have to go somewhere, and usually it's through a new hole in the newly-replaced boot. It took me 3, yes THREE, new steering knuckle boots on a Deuce to figure this one out (thank you M35-Tom and Erik's Military Supply for the help on that one!). I can't stress this enough: don't pack too much grease in there!! Just enough to coat moving parts is fine.

You can add grease when the old boot is removed; if it looks like grease needs to be added to coat moving parts, go for it...otherwise, inspect the existing grease for contaminants and/or foreign debris, remove if possible, and install new boot.

Now, if the existing grease inside the knuckle housing looks bad, then please take the extra time to remove the wheel/tire and the entire steering knuckle...you'll need to remove the contaminated grease & foreign debris so you can inspect the wheel bearings & races for damage, then repack & refill with new fresh grease.

So, in a sense, by quickly removing the old boot, you are actually giving yourself a reason to inspect the remaining grease & what you can see of the knuckle housing for potential problems.

HTH.

 

[TacticalDoc]

Wow...that's what I needed to know. Thanks SS55! I'll attempt it today and let you know how it goes. I'm sure I'll have more questions to make sure I did it right.

 

[TacticalDoc]

Changed it last night. It wasn't to bad. But, here are the things I would warn people new a doing it.

When you put the boot on make sure the holes line up before tightening the ring.

Make sure the screw on ring is the same size and the new one you have. The one on my truck was longer and easier to put back on.

When you thread the safety wire through the 12 bolts tighten them then back of slightly so that the hole line up. Thread the wire through and then tighten the bolt. Ti will bend the wire a little but is easier to thread through.

 

[silverstate55]

Glad it went OK for you, good job!

 

[capnkirk]

Where's the best place to buy boots for M939 trucks? I'd prefer not to have to replace these every 6 months.

 

[TacticalDoc]

Said a few bad words while doing it but felt good when it was done. Now, I have to change all the fluids and filters.

 

[TacticalDoc]

This is what it looked like when I first got it. It had leaves in the cab and damaged seats. A few months later it looks like this