How to remove/fix wheel hub with broken set screw tip

[Bilbo 3]

I have a 1996 Wheelhorse 520-H Garden Tractor with a Hydrostatic trans. Went to repair a tire, and found hub was wobbly on the axle. Pulled the setscrews and found part of the tip of one had broken off. The hub will move less than a quarter turn from stop and cannot be removed from the axle.

 

Is there a simple way to remove it and repair? The tractor isn't in the best of condition, so I am also considering just replacing the setscrew and tightening them down hard and running like that.  I am looking for advice. If I go the tightening route, what is the maximum torque I can use on the setscrews? I don't want to strip the threads.

 

Thanks in advance for any help!

 

[wallfish 17,079]

9 minutes ago, Bilbo said:

cannot be removed from the axle

Why is that?

The hub should be removed and inspected as it sounds like the key way slot in the hub is wollowed out which is why it will turn on the axle. That hub connection to the axle needs to be snug and set screws will not be strong enough to hold that connection tight.

Try to get that hub off. and because the key slot may be wollowed out, the remaining straight part of the slot needs to be lined up with the woodruff key in order for it to slide off. That woodruff key itself is or could be damaged as well so it may not slide through the hub slot easily.

[Bilbo 3]

Thank you for your quick reply! I Will try again to get off. I thought it mignt be blocked by the broken tip of the setscrew. Pic Attached.

[Ed Kennell 38,646]

Yes, you have to get the hub off,  but DO NOT pound on the hub to remove it.    The axle is held in the transmission by a small E clip that will be damaged if you pound on the hub.

 

It sounds like the hub is loose on the shaft and you need to get the key back in place so the hub can be pullled off with a puller.

[stevasaurus 22,863]

If it is loose on the shaft, tap the hub in and file any burrs that may be on the end of the axle.  

[Bilbo 3]

Well, I got it off. The setscrew that broke was the one over the key. Looking thru the hole I could see the the key was almost there at one end of travel. A few light taps to rotate and a few more back and forth, and it finally came off. I have attached pics of what it looks like. Apparently the setscrew on the key put a gouge in the shaft. I think the key should be tighter in the key way than it would be if I removed the bulge. Taking a break now. Thanks again for all the help. Any suggestions would be appreciated.

[Ed Kennell 38,646]

What does the hub look like?     No way the hub could rotate that far on the shaft unless  the  key way is totally gone in the hub.

[The Tuul Crib 7,337]

Whoa!!

[pacer 3,174]

Wow, thats about as bad as I've ever seen!! Not to put too fine a point on it but ............ you gonna need to replace it and more than likely the hub too. Us guys here on the forum have devised a few .... 'shade tree' fixes for these but I dont think you can salvage that one.

[lynnmor 7,354]

I would replace the axle, hub, key and set screws if it were mine.  This is what happens when folks don’t tighten the screws and run them till they quit.

Edited July 18, 2020 by lynnmor

[wallfish 17,079]

For a backyard hammer mechanic fix since it's already broke and the hub and axle need to be replaced.

You can key and lock the hub to the shaft by drilling and tapping threads into both. Lock it with 2 set screws into the threaded hole.

 

 

[Bilbo 3]

@wallfish

This sounds like the best course to take. At 75, this will probably outlast me. I am trying to keep it together as long as I can. I will let you know what I do.

[JoeM 7,874]

It is even tough to type this but, some JB weld might take up some slop also. Might do the set screw thing and JB??

Plus, If you know someone that welds pretty good that is an option too. I welded this on and it held until I replaced the axle. 

 

[Tractorhead 9,065]

 to 

 Dunno what machinery you have accessible. 
I would try to fill by upholding the raped sections and remachine them to original Style.

 

 

[JoeM 7,874]

Don't know about your terrain but it you have a lot of slopes and hilly stuff be careful with rigging that axle. If the hubs comes loose on a hill you have no brakes.  

[Bilbo 3]

Thamks again for all the suggestions. I might be able to find a used hub in the area. I am also go over to an old friend of mine that lives close. He is a machinist and has his own shop. I don't know if I can keep him sober enough to get the job done. We all will thing of something.

[953 nut 55,771]

 

13 hours ago, Bilbo said:

I might be able to find a used hub in the area

Lincoln at A-Z tractor can send you a good usedone.        https://a-ztractor.com/

[Bilbo 3]

Thank you "953 nut" and all that gave me assistance. I found a hub at a-ztractor.com and also a tire. The tire had developed a bubble and I think that might have caused the problem.

 

The hub has only one setscrew. I think I can fix that later, but I would still like to know if there is a torque for this setscrew. I set it to 15 ft-lbs an it seems to be OK, but I haven't done much mowing with all the rain.

[lynnmor 7,354]

If you put a very good hub on that very bad axle, you will be back at square one in no time.

[gwest_ca-(File Mod) 11,096]

29 minutes ago, Bilbo said:

I would still like to know if there is a torque for this setscrew. I set it to 15 ft-lbs an it seems to be OK, but I haven't done much mowing with all the rain.

 

Rear wheel hub set screw torque 28-32 Ft. Lb. or 39-45 Nm

Taken from this service manual

 

I think the key is to keep checking the torque after use for a while. Just snug the jamb nut because any more torque on the nut tends to pull the set screw back out.

 

Garry