Replace M939 Front Axle Seals and Boots DIY

[brazengoat06]

Im sure there is a thread out there but i cant seem to locate it. At present my main question is the size of the hub bearing retainer nut?

Im working on a 84 M923. What started out as a boot replacement turned into a seal job due to oil in the knuckle. Thanks

 

[elkhtr]

4-3/8 outer, 4-7/8 inner. 8 Point

 

[brazengoat06]

thanks a bunch! Got the Sockets ordered. any tips on replacing these seals or is it pretty straight forward?

 

[juanprado]

4-3/8 outer, 4-7/8 inner.

8 point!

 

[brazengoat06]

Thanks for correcting me on the 8 point sockets. I had to correct my order.

armynurse, Im looking for someone to go wheeling with in the near future once all this rain clears out and my leaks are fixed. If you would have any interest let me know. Don't wanna risk getting stuck by myself with nobody else big enough to pull me out ha.

 

[juanprado]

Thanks for correcting me on the 8 point sockets. I had to correct my order.

armynurse, Im looking for someone to go wheeling with in the near future once all this rain clears out and my leaks are fixed. If you would have any interest let me know. Don't wanna risk getting stuck by myself with nobody else big enough to pull me out ha.

no problem as they come in 6 and 8 pt.

 

[elkhtr]

8 point!

My bad.
I assume too much.

 

[silverstate55]

It's easier than an A2, I can tell you that much...I just replaced all 4 seals in my M931A2 driver's side hub...the 2 air seals for CTIS are a PITA to get seated properly.

 

[brazengoat06]

what should i pack the wheel bearings with? I kinda feel like bearing grease is bearing grease but...

 

[brazengoat06]

How does one remove the encased axle seal? Tech manual isn't clear on this final step. I've tried seal puller, slide hammer, pry bar, etc. Thanks for suggestions.

Ps. Still looking for grease suggestions.

 

[Ford Mechanic]

I used the valvoline red disc brake and wheel bearing grease for all the wheel bearings I do.

 

[brazengoat06]

Thanks. Also to clarify what I'm trying to do, I'm trying to remove the encased seal assembly from the axle housing and not the seal from the seal housing. Thanks for any tips.

 

[Ford Mechanic]

Thanks. Also to clarify what I'm trying to do, I'm trying to remove the encased seal assembly from the axle housing and not the seal from the seal housing. Thanks for any tips.

The one in the retainer in the end of the axle tube? I used a big slide hammer, but don't use the fingers to pull it out. Use the block the 2 fingers attach to instead. You'll have to put it through the seal and then thread it on the slide hammer. It takes some force to knock it out.

I have heard of folks pulling both sides down to that point and using a long piece of pipe inserted from the other side to knock it out.

 

[brazengoat06]

Ah that's a great idea! I'll give that a shot thanks

 

[Ford Mechanic]

Remember to put some sealant on the outside of that retainer when you put it back together

 

[brazengoat06]

ok im 90% complete on one side but i cant seem to get the boot back on. my trouble is the clamp ring the holds it to the knuckle. its the most frustrating thing! how do you get the boot back on the knuckle?!

 

[Ford Mechanic]

Yeah its a pain in the butt, the last one I did I ended up sewing the boot to the inner clamp with 5lb fishing line. And no it doesn't leak. One other thing I've done is to clean the axle tube real good and rtv the boot to the axle tube and then give it a day to set. You must use the grey high torque rtv this way, the other stuff isn't strong enough.

 

[brazengoat06]

Sounds like this will be the worst part...

 

[brazengoat06]

Ok what i did was i took the ring off and pushed the boot all the way on passed the groove which would be towards the knuckle. then i installed the ring just barely threading the bolt. next i painstakingly pryed and massaged the boot back towards the groove. i did find a helper at one point in this procedure to turn the steering wheel back and forth as i worked the boot back. anyways i got it in one try but it took about an hours time. Also hoping there are no holes in the boot now, but they seem pretty tough so i doubt it.

 

[Ford Mechanic]

I've put several on that in 6 months later they have a hole in one.