Washed out hub keyway

[RetroMower 349]

I know I know its green  pretend its red and besides this applies to any hubs. I noticed my 1/4" keyways were both heavily wallowed out, not to a completely unusable state given the future of this tractor but enough I thought it needed attention. My question to the community is would a second broached keyway and an accompanying 2nd set screw be an acceptable option or would it seriously damage the integrity of these hubs? There are 3 flat spots cast into them to seemingly offer future spots for multiple set screws. The axle shafts are not great but new tight woodruff keys made them look much better. Sorry for the fuzzy image but a close zoom is not easy

[ebinmaine 68,293]

Broach a second keyway 90⁰ from that one. Add another set screw. 

Use NEW set screws. 

If you REALLY want to feel good about it there's a loctite coating... ((Green??)) For extra hold.  

 

[pacer 3,174]

Another broach is common - I recently had the PTO hub off a D series and found some PO had did another broach at about the 4 oclock position. I dont imagine it really matters the position. On the horses hubs I add TWO extra set screws! all to often they have developed some looseness.

[Achto 27,751]

If you don't have the means to broach the new keyway, @WHX?? offers his service to do it. 

[DougC 2,641]

I installed 2 new rear hubs before last winter on my 520 H snow pusher and both are already loose and I replaced both rear axle seals and used new set screws and keys fit real tight in the axles and the hubs at this stage I just  (swear word) work the hell out of it and call it normal. 

[RetroMower 349]

1 hour ago, ebinmaine said:

Broach a second keyway 90⁰ from that one. Add another set screw. 

Use NEW set screws. 

If you REALLY want to feel good about it there's a loctite coating... ((Green??)) For extra hold.  

 

I wish I could go 90° but the the 3 cast flat spots for set screws are 120° apart. And I think I'll use red loctite just to aggravate 🤣

 

4 minutes ago, Achto said:

If you don't have the means to broach the new keyway, @WHX?? offers his service to do it. 

I do have a broach set but thank you for the offer. 😁👍

[ebinmaine 68,293]

50 minutes ago, DougC said:

I installed 2 new rear hubs before last winter on my 520 H snow pusher and both are already loose and I replaced both rear axle seals and used new set screws and keys fit real tight in the axles and the hubs at this stage I just  (swear word) work the hell out of it and call it normal. 

I've read several times it is considered normal to keep tightening the set screws. 

I haven't had a problem until Cinnamon Horse C160-8. 

That one loosens the hubs evey few months.  

 

New style hubs. All 4 new set screws. 

[Snoopy11 5,714]

33 minutes ago, ebinmaine said:

That one loosens the hubs evey few months. 

Have you tried using a battery impact on it?

 

I had a similar problem with HellHorse... then I got out my battery impact, snapped the trigger a couple of times, and it hasn't backed out since.

 

Don

[ebinmaine 68,293]

9 minutes ago, Snoopy11 said:

Have you tried using a battery impact on it?

 

I had a similar problem with HellHorse... then I got out my battery impact, snapped the trigger a couple of times, and it hasn't backed out since.

 

Don

I have in fact yes. 

Thought that would solve it. 

 

It's a heavy tractor. On rough terrain. Pulling heavy loads. 

Stands to reason it would loosen up a tad. 

[Snoopy11 5,714]

5 minutes ago, ebinmaine said:

I have in fact yes. 

Thought that would solve it. 

 

It's a heavy tractor. On rough terrain. Pulling heavy loads. 

Stands to reason it would loosen up a tad. 

Has anyone tried a spring washer?

 

I have often pondered something like this:

 

 

Or some kind of barrel spring like this:

 

 

Don

Edited January 4, 2022 by Snoopy11

[ebinmaine 68,293]

Just now, Snoopy11 said:

spring washer

I'm not familiar with them.  

[Snoopy11 5,714]

1 minute ago, ebinmaine said:

I'm not familiar with them.  

Well, if you have ever looked at the idle adjustment on a weed eater or gas blower, you notice that there is a spring on the adjustment screw for the idle. This little spring keeps the idle screw in the same position that you place it, keeping the screw from just loosening and falling out...

 

Same concept, just on a larger scale.

 

Just an idea/concept.

 

Don

[pacer 3,174]

Is it just with my herd of 'D' models, or do their axles not seem to have the problem - in fact just the opposite seemingly. On 3 occasions I have had to resort to a 20 ton press to get a hub off, and even then the press was at its limit POWING it loose. Bout had to clean my undies when it popped!!!

[Snoopy11 5,714]

Basically it is a compression spring like this:

 

 

You could do the same thing on a larger scale...

 

Don

Edited January 4, 2022 by Snoopy11

[Jeff-C175 7,203]

2 hours ago, RetroMower said:

red loctite

 

Loctite 660 is what you want

 

https://www.henkel-adhesives.com/us/en/product/retaining-compounds/loctite_660.html

 

And unless you're Popeye, you will NEVER get the 30 ft lb of torque for those setscrews with a combination wrench.  You need an 8 point socket and ratchet.  And check them now and then.

Edited January 4, 2022 by Jeff-C175

[Snoopy11 5,714]

If I did a "trial" of something like the above, I would probably end up using some valve springs and retainers that I have laying around...

 

 

But... in the end, it would probably be easier to use loctite...

 

Don

Edited January 4, 2022 by Snoopy11

[ebinmaine 68,293]

9 minutes ago, pacer said:

Is it just with my herd of 'D' models, or do their axles not seem to have the problem - in fact just the opposite seemingly. On 3 occasions I have had to resort to a 20 ton press to get a hub off, and even then the press was at its limit POWING it loose. Bout had to clean my undies when it popped!!!

 

 

Seems to be that unless a wheel seal has been leaking the hubs are seriously rust welded in place.  

I should clarify that my C-160 was restored nearly 3 years ago. 

Everything is clean and rust free.  

 

[ri702bill 8,490]

I added a second setscrew on the C81 hubs, 90 degrees to the original - had the hub walk inward prior to towards the Unidrive. Reassembled by tightening the original  one over the woodruff key and used a 3/8 tap drill (5/16") in the other hole to dimple the shaft to just make a conical surface below the 1-1/8" axle diameter - the screw will raise a burr when tightened, but not raised to interfere with hub removal. Blow out the chips, insert the screw and tighten to recommended torque.

No loosing issues.

[lynnmor 7,353]

The clamping force of a 3/8-16 screw will be about 4900 pounds, depending on torque.  Using a spring, the clamping force will be the spring rate, maybe 100 pounds.

 

Use a second set screw if it only has one, as mentioned above.  That second screw that is off the key should have a flat or drill point machined into the axle, some axles may be too hard to drill so grind a flat at the correct location.

[Jeff-C175 7,203]

2 hours ago, lynnmor said:

machined into the axle

 

The NEW and SHARP setscrew should do it's own dimpling.  Tighten, then loosen and tighten again to 30 ft lb.

[lynnmor 7,353]

34 minutes ago, Jeff-C175 said:

 

The NEW and SHARP setscrew should do it's own dimpling.  Tighten, then loosen and tighten again to 30 ft lb.

Those axles are hardened where the wheel bearing runs, that area can extend out to the set screw. 

[Jeff-C175 7,203]

3 minutes ago, lynnmor said:

Those axles are hardened where the wheel bearing runs, that area can extend out to the set screw. 

 

I may not have seen as many as you have, but every one I've ever seen has had a dimple where the set screw sat.  Just sayin'... 

 

 

[roadapples 6,983]

5 hours ago, ri702bill said:

I added a second setscrew on the C81 hubs, 90 degrees to the original - had the hub walk inward prior to towards the Unidrive. Reassembled by tightening the original  one over the woodruff key and used a 3/8 tap drill (5/16") in the other hole to dimple the shaft to just make a conical surface below the 1-1/8" axle diameter - the screw will raise a burr when tightened, but not raised to interfere with hub removal. Blow out the chips, insert the screw and tighten to recommended torque.

No loosing issues.

I've done basically the same thing on 2 of mine. But I use a centering punch and then remove the hub before using the drill. I went deep enough so a thread or two would be in the hole.

[bc.gold 3,403]

I often come across where two Allen type set screws have been used in the same hole, one long the other short. Kinda like using a pal nut.

[pacer 3,174]

9 minutes ago, bc.gold said:

two Allen type set screws have been used in the same hole,

 

That is very common on machining tools (at least older ones) Few yrs back I got into finding old lathes, mills, grinders, etc and rebuilding them (sorta led me into horses) and the first time I ran into the double set screw bout messed my mind up trying to get a piece off of one - my buddy came to the rescue when he asked if I had I ckd for a second screw .... doh!