Packing Tool for M35A3 Hub Inner Bearing

[HDN]

After doing some research I found the bearings are not only very expensive but the inner bearings are packed at the factory by timken and the inner seal is part of the bearing and not available separately. I suppose if the seal fails the bearing is meant to be replaced. With inner bearings in the 800$ each range I decided to try to clean the seals and repack them and since there is not suppose to be diff oil in the bearings any way I would order new outer seals to keep the diff oil out of the bearings. I have attached a series of photos of the process, it seems the bearings, with the CTIS system, include bezzels that are part of the inner bearing race and protrude into an air seal in the inboard hub. The inner grease seal is driven (metal to metal seal) into a small lip that is machined into the outer bearing race with the inner part of the seal (also metal to metal seal) is driven onto a small lip machined into the inner race. I was conserned about damaging the seal by driving it off of the inner race so I left it attached to the race and packed the bearing from the inner side (sort of time consuming) then applied a light layer of aviation permatex to the outer perimeter of the seal and gently drove it back into the outer race.

This fellow wasn't wrong when he said packing the M35A3's inner wheel bearings in this manner was time-consuming, so I printed a tool to speed up the process.





My tool forces grease into the ~1.5 mm gap between the cage and inner race, forcing all the old gunk out from above the rollers and through the bottom gap between the cage and the lip that's driven onto the bearing.

I printed this with black ABS plastic (the same plastic Lego bricks are made from). I printed the tool in about 3 hours.

 

[Mullaney]

This fellow wasn't wrong when he said packing the M35A3's inner wheel bearings in this manner was time-consuming, so I printed a tool to speed up the process.

View attachment 900081

View attachment 900082

My tool forces grease into the ~1.5 mm gap between the cage and inner race, forcing all the old gunk out from above the rollers and through the bottom gap between the cage and the lip that's driven onto the bearing.

I printed this with black ABS plastic (the same plastic Lego bricks are made from). I printed the tool in about 3 hours.

.
Nice!
Definitely easier than by hand for sure.

.

 

[simp5782]

Needle grease fitting adapter on the grease gun

 

[HDN]

Needle grease fitting adapter on the grease gun

I don't have a grease needle here - something I need to add to my toolbox. The guy I originally quoted tried a grease needle and it wouldn't fit between the cage and inner race - maybe his grease needle was too big?

If any ESP truck owners want to print this themselves I have the STLs attached to this post. If someone wants me to print this just send me a PM. I'll probably want a few bucks for it though - not sure how much since shipping costs are kinda crazy these days. Note that if you print this yourself, be sure to disable any settings for hole size compensation as I designed the parts to fit together and on the wheel bearing.

 

[chucky]

What happend to just putting the grease in the palm of your hand and rakeing the bearning/race down your hand so you can see the grease start coming thru then turn the bearing around till you have it all done ? Its really fast i thought !

 

[HDN]

What happend to just putting the grease in the palm of your hand and rakeing the bearning/race down your hand so you can see the grease start coming thru then turn the bearing around till you have it all done ? Its really fast i thought !

The M35A3 inner bearings are completely sealed on the larger diameter side and therefore can't be packed from that side without destructive disassembly. They're prepacked by Timken and probably considered completely disposable when following the packing interval in the LO.

They still cost around $550 each even though this is the only truck I know of that uses them, though according to a NSN site the Navy may still use them for something - what that is I have no clue.



The only option for packing these bearings is to do it from the small diameter side through a ~1.5 mm gap directly adjacent to a ~12 mm tall protrusion that's part of what gets driven into the hub. With those two things, hand-packing turns into finger-packing, which really sucks to do, especially if you don't have the fingers of a 3 year-old. By the point I was making a little progress finger-packing the thing, that was when I was like "Screw this, I'm going to make a tool to speed this up!"



The outer bearing isn't sealed up on larger diameter side like the inner bearing and can be hand-packed normally.

Most of this I learned from info posted here by @michaelpilot1 @glcaines and @rtk . I just take credit for the tool

This setup seems unique to the M44A3 probably due to using recycled M44 axles and retrofitting CTIS components to them. The M939A2 and FMTV trucks seem to deliver air to the tires using a completely different setup altogether.

 

[Karl kostman]

One of the reasons I would not drive or own a truck with CTIS on it!

 

[chucky]

The M35A3 inner bearings are completely sealed on the larger diameter side and therefore can't be packed from that side without destructive disassembly. They're prepacked by Timken and probably considered completely disposable when following the packing interval in the LO.

They still cost around $550 each even though this is the only truck I know of that uses them, though according to a NSN site the Navy may still use them for something - what that is I have no clue.

View attachment 900180

The only option for packing these bearings is to do it from the small diameter side through a ~1.5 mm gap directly adjacent to a ~12 mm tall protrusion that's part of what gets driven into the hub. With those two things, hand-packing turns into finger-packing, which really sucks to do, especially if you don't have the fingers of a 3 year-old. By the point I was making a little progress finger-packing the thing, that was when I was like "Screw this, I'm going to make a tool to speed this up!"

View attachment 900179

The outer bearing isn't sealed up on larger diameter side like the inner bearing and can be hand-packed normally.

Most of this I learned from info posted here by @michaelpilot1 @glcaines and @rtk . I just take credit for the tool

This setup seems unique to the M44A3 probably due to using recycled M44 axles and retrofitting CTIS components to them. The M939A2 and FMTV trucks seem to deliver air to the tires using a completely different setup altogether.

What if you drill and tap your back sleve or make your piece to go ahead and cover the whole cage and install a grease zert in it and lay the bearing on say a bench top with say a wooden piece that covers the whole bearnging packer then in the center screw that top plate into the bench tight with deck screws then put the grease gun to it and see if can force the grease every where ! Of coarse you could make a better way to cage the bearing to force grease in but just to see try the crude way first

 

[HDN]

What if you drill and tap your back sleve or make your piece to go ahead and cover the whole cage and install a grease zert in it and lay the bearing on say a bench top with say a wooden piece that covers the whole bearnging packer then in the center screw that top plate into the bench tight with deck screws then put the grease gun to it and see if can force the grease every where ! Of coarse you could make a better way to cage the bearing to force grease in but just to see try the crude way first

You just gave me another idea - make a grease reservoir to fill on the small diameter end of the bearing and use some kind of plunger to force the stuff down into the race - pack a whole chunk of the bearing in one go

 

[chucky]

You just gave me another idea - make a grease reservoir to fill on the small diameter end of the bearing and use some kind of plunger to force the stuff down into the race - pack a whole chunk of the bearing in one go

THREADALL AND BIG WASHER and nut thru the benchtop to sorta act like hydraulic force to push the grease

 

[HDN]

THREADALL AND BIG WASHER and nut thru the benchtop to sorta act like hydraulic force to push the grease

A C-clamp would do the trick!