M35A3 Front Boot Replacement

[YOUNG GUN]

I'm planning on replacing both front boots on the A3 this weekend because they are torn. I'm going with the solid silicone boots from Erik's and I also bought new axle seals to replace since I'm going to tear into it anyway. I have all the tools, but are there any other parts I should have on hand?

I'm reading up on threads from guys who have already done this and have found some good info, but I have not found anything specifically on the A3 with the CTIS.

If anyone has done this on the A3, I'd appreciate any tips or advise you may have on this. I imagine there are some differences due to the CTIS, just looking at the TM's and my truck I can see there is a tube that goes through a slot in the knuckle; On my truck I can see that the tube has beeen sealed with some sort of goop on the outside of the knuckle around the slot; What type of sealant is best to replace this?

Any advise is greatly appreciated, as this looks like it could be a bigger project than I previously thought.

 

[YOUNG GUN]

Got my right front boot done this weekend, with some help from Beerslayer.
Thanks again for the help, and I look forward to the opportunity to return the favor.

In total, it took about 2 hours to tear it apart on friday night, and about 6.5 hours on monday to button it all back up. (actual work time, not lunch, cleanup, etc.) I think the left front will take half the time unless I run into something bad.
Here's a few pictures I took during the project (yes, I should've taken more).
Look at that sludge that drooled out of the knuckle when I removed the spindle!

 

[doghead]

That sludge is most likely from leaking axle shaft seals allowing oil to mix with grease and some water(from a bad boot).

You did change your axle shaft seal while you were there, right?


Also, that improvised jack stand looks unsafe to me.

 

[goodguyzy]

good job, there a lot of items on the A3 that many members havent got into yet. Sounds like you guys will be the official axle experts now.

 

[YOUNG GUN]

I would agree in regards to the sludge...Nasty stuff!

Yes, I did change the inner axle seal. (that would suck if I missed that one)

I KNEW someone would catch my "custom" jack stands! I'll sell a set if anyone wants them?

On a serious note:
I chock the rear wheels, the "custom" stands are really only being used to keep the front of the truck stable (just enough weight on them to keep it from moving), the front of the truck is primarily being supported with my 5 ton overhead crane, which I love dearly.

 

[YOUNG GUN]

good job, there a lot of items on the A3 that many members havent got into yet. Sounds like you guys will be the official axle experts now.

Thanks, I hope to be an expert on the A3 at some point.
I've got much learning to do, and what better way to do it than to work on the truck

 

[1 Patriot-of-many]

How do you know if you need to replace that stuff? I don't see any leaks anywhere on mine, except a coupls coolant leaks I took care of and air leak from axle vent that I know I need to replace a seal or two apparently.

 

[Clay James]

Nice job! I wish I had a shop like that for my trucks. I just got done doing it all out in the open.

 

[YOUNG GUN]

How do you know if you need to replace that stuff? I don't see any leaks anywhere on mine, except a coupls coolant leaks I took care of and air leak from axle vent that I know I need to replace a seal or two apparently.

Both boots are torn on mine, the right side worse than the left.
The right side (the one I replaced) was dropping globs of the grease and gear oil sludge onto the inside of my tire and subsequently slinging it all over under the fender on the right side.
The gear oil was coming from the bad inner axle seal, and all the grease I assume is buildup from years of pumping grease into the kingpin bushings.
Only the right side boot was actually leaking, but after closely inspecting the other side, I found (2) holes/tears in that one as well that we're just barely wet with grease (very hard to see without turning full lockout both directions and looking in the boot folds/grooves) so I'll be replacing the left boot and inner axle seal on that one next.
I don't plan on taking my truck swimming, but I don't want to risk the contamination regardless.

I plan on replacing all of my inner axle seals, quad seals, and repacking all wheel bearings; It doesn't cost that much, and it's good piece of mind to know its all been serviced properly.
All I had to do to persuade myself, was look up the cost and availability of the CTIS bearings... I'd rather NOT replace them unless I really have to.

The air leaking from the axle vent is likely the quad seals.

Also, I'd go through all your breather vents to make sure they are not plugged, several of mine were, including the one on the front of my right knuckle.

Good luck!

 

[YOUNG GUN]

Nice job! I wish I had a shop like that for my trucks. I just got done doing it all out in the open.

Thanks!
I'm very fortunate I don't have to work on my stuff in the crappy weather we have here during Oregon winters.

 

[Clay James]

Check your spindle bushings too. Mine had a ton of play which destroys the seals. I replaced my seals twice and they leaked imminently, then I realized I should check them. My friends truck also needed new ones so it seems like a common wear point. Shouldn't be a problem on an A3 since they usually have low miles but it's worth a look.

 

[doghead]

I plan on replacing all of my inner axle seals, quad seals, and repacking all wheel bearings; It doesn't cost that much, and it's good piece of mind to know its all been serviced properly.

 

[YOUNG GUN]

Check your spindle bushings too. Mine had a ton of play which destroys the seals. I replaced my seals twice and they leaked imminently, then I realized I should check them. My friends truck also needed new ones so it seems like a common wear point. Shouldn't be a problem on an A3 since they usually have low miles but it's worth a look.

After cleaning the spindle, I did a visual inspection of the bushing and it seamed to have little to no significant wear at all. I also checked by trying to move the end of the axle that sticks out of the spindle (after install) sideways for any free play and there was none, I can't say that checking it this way is correct, but it seems this would be sufficient.