Rebuilding the IRS Hubs

You do know you can edit your original post using the pen icon lower right.

No, didn’t know that. Thanks Robin

Yeah Kevin, I’ll take Robin’s message to heart. Even though I say I’ve been in an office all my life, I’ve also been using my hands for as long as I can remember too and I’ve heard many stories such as you state. It is why I only wear the one ring and nothing around my neck and I’m careful about what sort of sleeves are worn when I work. It is a good message Robin’s delivered!

On another note, I am going to be out of pocket for about 5 days with the family, so I won’t be online very much until we get back home.

In our Hanger at the Nat’l Guard, we had a poster with a picture of a hand, finger bone sticking out, flesh lying beside it, and a ring… caption, “Take off your ring, not the Finger” Nuff said…

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I’ll embed this to minimize any shock and revulsion… I play guitar.

A lot of box trucks have hooks on the inside wall from which to hang padded mats. A BIL caught his wedding band on one as he jumped out of the back of a truck. Loading dock workers picked him up and unhooked him. No lasting damage but his finger was cut and swollen.

Because of this…

…This was the outcome.

All timely reminders I sometimes forget to take mine off ……. One othering they can also scratch nice paint work !

As readers know I decided to replace everything that was wearable: seals, bearings, and U-joints. I made another thread to sort out the part numbers here:

Onward then to remove the outer bearing on the first axle I’m working on. The bearings do look in excellent shape and I removed it without damage. The seal is old enough to appear to be leather. Is that possible? It has a number on it, but no manufacturer. Here’s the setup and the parts removed:




So now to clean it all and set aside until parts arrive. Meanwhile, on to the other axle - RH side.

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With the replacement splined yoke cleaned and ready for a fit check, I lightly greased all the splines and inserted the yoke. It fits tight and there is no discernible relative motion between the hub and the splined yoke…good to go.

I deburred the edges of the yoke where the bearing caps fit to capture the spider (trunnion). If you don’t do this, a burr can cause a bad fit of the bearing cap and hence a “tight” U-Joint. I also check the fit of the snap rings as a damaged Snap Ring groove is why I replace the splined yoke.


Next I removed both outer races of the inner and outer bearings. The one for the inner bearing was easy on the floor press with a square piece of metal that caught the edge of the race. The outer bearings race presented more difficulty and I couldn’t come up with anything suitable to grab the edges. So I resorted to tapping that outer race out with a hammer and punch. I didn’t take any pics of either race removal as it is pretty standard procedure. With both bearings (cone and race) out, I was able to closely inspect them. Both would have been fine to re-use IMO. Still, safe practice to go with new. Note the “made in England” Timkens.


Tomorrow I’ll thoroughly clean the hub and get it ready for re-assembly. I feel I need to address the distorted portion of the inner seal ring where it had received a blow. The black pointer and the last pic show the current condition. The pic with the yellow pointer and the pic after that show how the seal is distorted out of round by the damage.
I could use advice as to how best fix this. My plan is to lightly grind the damage back to as “round” as I can do by hand.



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Hello Scot,
Whenever there is a bruise causing displaced metal, I’ll massage as much of the displaced metal back to from whence it came before resorting to grinding or other metal removal methods.

Although not the same curvature (due to being a different diameter), sit the old bearing cup in the bore that takes the seal and with its circumference bearing against the displaced metal, use a hammer and punch to drive the bearing cup to move the metal back to where it came from. I would then use a scraper to do any finishing, if required. I have made an assortment of scrapers of various shapes, out of HSS power hacksaw blades; however, as the material you’re working with is aluminum alloy, a scraper made of Mild Steel will work.

If you have access to a lathe, turn up a steel disk 0.002" (0.05mm) smaller than the diameter of the seal, with a short lead in taper, or radius between the face and circumference, to use by tapping or pressing into place to finally size and and finish the repair area.

Regards,

Bill

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Well Thank you Bill. Good term…bruised. And your described method gives me good food for thought.

The bruised part of the Aluminum casting is brittle and the very outer most circumference of it just came away with a pick. You can see it’s gone in the last photo. And more “slivers” came away elsewhere. The inner face of the cup at the bruised portion is quite rough - I think because the casting just didn’t like being compressed via impact. So that is where I start.

I like this approach. Will heat help any do you think? During this metal movement phase?

And the scraper is a great idea and I’ll do just that vs. using a small grindstone on a Dremel. I use scrapers to do fine finishing on wood and when I want a bit more bite, I burnish the edge. Here’s a video showing that:
https://www.google.com/search?q=burnish+an+edge+into+a+scraper&rlz=1C1GCEA_enUS811US811&oq=burnish&aqs=chrome.2.69i57j0i433i512j69i59j0i131i433i512l2j0i512l2j0i433i512j0i512l2.9521j1j7&sourceid=chrome&ie=UTF-8#kpvalbx=_BycCY_O3KrvMkPIPh8-ruAw34

I’ll use a hack saw blade to make one as you suggest - brilliant!

I don’t have a lathe, but have friends that do. However I’ve found a disc I use with the press that is conveniently about 1/32" smaller than the seal’s cup bore. A bit smaller than you suggest, but I think I can use brass shim stock to fit to the opposite 180 deg of the disc to make a tight fit. If that doesn’t get it, I’ll go to the lathe owners. Your concept is to insert the disc sort of like a freeze plug (or whatever you call those in Austrailia); that being the disc is perfectly round and when tapped into place it will help re-establish the roundness of the bruised metal. Also brilliant?

Thank you so much.

Hello Scot,
Not much, if anything at all. You could warm it so that its not freezing cold, but avoid getting it very hot, for aluminum is Hot Short.

Yes, they make excellent wood working scrapers, I used to make target rifle stocks many years ago and scrapers made from HSS hacksaw blades made excellent scrapers to scrape the action into the timber to get a very close fit and no distorting forces being exerted by the stock on the action when the securing bolts were tightened.

Also many years ago, I was in Europe prior to the World 300 Meter Target Rifle Shooting Championships and staying with my Dutch girlfriend at her parents home. A new, small bore target rifle was made available for me to practice with and after sighting it in, the first 60 shot practice match resulted in a score of 595/600. When I returned to their home that day, I went to a small workshop where garden tools and the like were kept, found an old hacksaw blade, made a scraper, borrowed lipstick from the girlfriend (Vivian) to use as a marking medium and proceeded to scrape the action into the stock for a better fit. The father thought I was a big head, because 595/600 equaled the Dutch National Small Bore record.

I repeated the scaping exercise over the next few days and over the two months I was there before the World Championships, I shot 42 x 60 shot English Matches with an average score of 598.5, including the first practice match score of 595.

Regards,

Bill

Dont go out in the wind, Bill: all your tags will blow off.

:wink::grimacing:

It gets better Paul. I shot in the Belgium National 300M Championships as a lead up to the World Championship and won with a record score that still stands today, at 598/600.

Talking of wind, it gets fairly windy in New Zealand. I used to go there every year for the Belinger Belt competition, the equivalent of the Queen’s or King’s prize in British Commonwealth Countries. After completing the 900 yard match, I looked at the amount of wind adjustment I had no my back sight, and it equated to the centre line of the barrel pointing 60 feet to the right of the target with the projectile being blown onto the target during its flight.

Regards,

Bill

Awesome Bill. I’m curious about the term Hot Short. I know what it means, but over a year ago I had an Oil Sump from my FHC that was “weeping”. Two expert welders tried to fix it, but it always cracked on cool down…no matter how slowly: blankets, oven, etc. I am still curious as to what the problem was.

What was the caliber you shot at the Dutch Nationals? I think 22 rimfire, but not at 300 yds. Must be .223 or such? I shoot vintage (Winchester Model 52B) and still hold the North Carolina record - I think. I haven’t shot for years. And definitely not in your league. Hats Off!

I am having difficulty getting any force behind the hammer to race on the metal displacement. Access inside the hub isn’t perfect. No going to use heat at all. Just cold work what I can and then turn to scraping. I’ll get it eventually but working to do no further damage.

“Awesome Bill. I’m curious about the term Hot Short. I know what it means, but over a year ago I had an Oil Sump from my FHC that was “weeping”. Two expert welders tried to fix it, but it always cracked on cool down…no matter how slowly: blankets, oven, etc. I am still curious as to what the problem was.”

Interesting, maybe a bit off topic, but my sump had PO accident damage untidily welded. I cleaned it up & had it expertly welded on the inside. It distorted somewhat but no cracks & looks much better.




Hi Randall. I’ve quite a thread on the oil sump problems. One of the welders has successfully welded about 30 Jag pans with MIG without issue; never saw a problem such as mine. The other welder is my son, a union Millwright who teaches welding and used every trick in the book with TIG - ramp waves, triangular waves, square waves, a variety of sticks, and a lot more. 3 days of ugly work for no success. Sometimes it would crack immediately, sometimes it would take 20 minutes, but every weld cracked eventually.
I bought an excellent sump from a 4.2 and then found one from a 3.8. If anyone needs a 4.2 sump…

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So here are the results for today. I THINK I GOT IT!
The damaged bruise area was very resistant to being pounded back to shape. I used a variety of circular tools to push it back with hammer and punch. I used the shock keepers to make a rounded impact; then a close fitting thick washer and finally the used outer race of the inner bearing that was a bit smaller than the seal cup size. If it moved, I couldn’t see it. So I made a scraper out of a saw blade held with vice grips. That was slow going and I stopped several times to attempt to re-insert the used seal that was an original Jag seal mostly comprised of metal. No dice. Finally I applied the Dremel with grindstone and winged it by hand. It really needed a mill to do this.

But I got very close and it appeared the used seal might go in. So I took the saw-blade scraper and scraped the inner side of the seal’s cup hole and it came out very smooth (yeah!). A little grease to help and the seal went in quite nicely. I had rotated the seal so the damaged part of the seal was not aligned with the bruise. That’s the blue dye on the seal and the cup bruise is the blue dye on the carrier housing itself. The seal seated on to the cup flange nice and tight. So I think I got it! Thank you Bill for your direction! I’m satisfied with the vast improvement of the bruise over what I started with. But I’ll use the calipers now to find the out-of-round and then work that with the scraper. It should be good.







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Hello Scot,
Hot Short refers to the material’s propensity to cracking at elevated temperature, particularly just short of melting point.

Many casting, whether aluminum or iron are hard to deal with unless the temperature of the whole component can be controlled. The town I grew up in had a Blacksmith Shop and I had an arrangement whereby I would take cast iron parts to be welded, with all the weld prep done, there after closing time to be put in the furnace. The part was brought up to cherry red heat, the weld completed and the part put back in the furnace to cool down with the furnace overnight. The part was still mighty hot the next morning, but cool enough that it avoided cracking as it cooled further.

It was the Belgium and World Championships I went to Europe for where I used an Angel M80 Target Rifle in .308 Winchester. You can’t really do that much practice with the 300M rifle that you will use in competition, because you will wear the barrel out, so I practiced using the scaled down version of the event at 50 Metres using a 0.22 calibre target rifle in Holland where a rifle range was made available to me for practice.

You could weld a length of sturdy rod to the old bearing cup (perpendicular to the face surface of the cup) then, with the bearing cup held in place, hit the side of the rod; the longer the rod (up to a limit), and the further you can hold the rod from the bearing cup, the more of the force applied by hitting it will be directed in the right direction.

Another method would be to turn up a few disks, starting with one of a diameter that won’t quite fit into the bore with it damaged as is. Drill a hole in the disk and have a plate with a similar hole, that can be placed in the bore for the outer bearing and using a long bolt, or Threaded Rod, pull the plate into the damaged bore. Repeat this exercise with progressively larger diameter plates for the damaged bore until within a few thou of the seal diameter.

Regards,

Bill

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