Wheel Hubs and Keys

[JamesBe1 82]

So what's the deal with wheel hubs, woodruff keys, hub depth, and set screws?

 

I have a C-120 8-Speed Manual (61-12k802)

 

I had to remove a tire to change out a torn tire valve, and the wheel and hub were stuck together.  I figured it would be simpler to just loosen the hub and pull them both off.  It was pretty easy to get the hub and wheel of together.  I replace the valve, and put everything back together, and took it for a spin.  I got a few hundred feet, and it stopped.  The axle was spinning in the hub. 

 

I took the wheel and hub off this morning, and with a lot of swearing (it really helps a lot!), separated the hub from the wheel.  Looking inside the hub, I can see a long groove worn in the hub about the length of the key.  Luckily, I found another hub on an old transmission under a bench in my barn.  Both were the same size.  I put the new hub on the axle, and am wondering about the hub depth.  Should the depth be set so that the screw tightens against the top of the key?  If so, then the end of the axle is flush with the end of the hub, but the key is no longer in the keyway.  The keyway doesn't appear to run the length of the hub.  Should it?  

If I move the hub closer to the transmission, the axle is sticking out of the hub about two inches, and the screw tightens against the axle.  This allows the key to be in the keyway at the end of the hub.  I can see this arrangement working, but it doesn't look copaceitc.

 

I can't check the other hub without pulling off the wheel weight, so I figured I would check with the braintrust there first.  Anyone know the correct assemble??  Also, do hubs wear out so that the keyway is lost?

 

James

 

 

[pfrederi 17,895]

Did you put the woodruff key back in...and did it stay?  They have a tendency to get pushed out of their slot as you push the hub back on you may not have noticed it.

 

Woodruff key have a half moon slot in the axles not the length of the axle.  the correct hub should have teh setscrew hole line up with the center of they key when the hub is flush with the end of the axle.

[JamesBe1 82]

Hi Fred!

Yes, I got the woodruff key back in correctly.  I've had it apart several times now scratching my head.  I think I have figured out the issue (tldr: worn hubs).

 

I cleaned the inside of the old hub real well to get a good look at what was going on.  I also removed the new (really a used) hub as well is a third one from the old transmission and took a close look at all three.  All of them have a deep grove worn into the inside of the hub to greater or lesser degree.  On the original hub, the groove was only about the width of a woodruff key  It made it look like a double wide key-way for part of the length).  On the other two hubs, the groove on each of them went much further around the inside of the hubs.  One of them was almost all the way around.  All three are shot!

 

I'll try and post a pic if I can find a way of getting a clean shot of the inside of a hub.

 

Have any leads on an inexpensive hub (105763)?

 

On a related note, I had a similar problem on the other axle back in the 90's (yeah, that long ago).  The hub was loosening up and moving in and out along the length of the axle.  It was a major headache.  Out of frustration one day, I took the key out and drove the set screw into the axle key slot.  It worked and I haven't looked back since.  I've had it off a time or two, and it appears to be holding up ok.  I don't think it's an approach that I want to repeat if I can find a better way.

[Ed Kennell 38,715]

I always add a second set screw 90 degrees from the original.  It takes up any clearance in a worn hub/axle and prevents any movement that will cause the wear.

[JamesBe1 82]

1 hour ago, Ed Kennell said:

I always add a second set screw 90 degrees from the original.  It takes up any clearance in a worn hub/axle and prevents any movement that will cause the wear.

 

That's an excellent idea.  I see that wheel horse incorporated that into their later hubs.  I guess great minds think alike.

 

I was also toying with the idea of cutting a notch into the top of the key for the set screw to rest in.  That way, if the set screw were to loosen up and the hub move in or out, the set screw would push the key in the same direction and it would only go so far before the key kept it in place.  Not sure if I am going to try that.  I'll have to ponder it a bit more.

 

Since my hub is damaged, I think I am just going to replace it.  I bought a pair of used one off the site that we all know and love (or hate).

[oldredrider 2,549]

You can also have a machine shop broach a new key way at 90° to save your old hubs. About $15-20.

[JamesBe1 82]

25 minutes ago, oldredrider said:

You can also have a machine shop broach a new key way at 90° to save your old hubs. About $15-20.

That's a great idea!  While I'm at it, I should have them drill and tap a for a second set screw. 

[WHX?? 49,189]

I enjoy doing it myself,  nothing better than drilling and tapping cast but if you don't have the tools understandable. I'm sure any machine shop would do it for a Lincoln.

[WHX?? 49,189]

This was another boogered up hub but notice where  the set screw is there was good meat yet. This was from me running the tractor with the hub walking.... ...........Since this tractor is no longer a heavy worker I put in the other set screw and . 

[JamesBe1 82]

15 minutes ago, WHX11 said:

I enjoy doing it myself,  nothing better than drilling and tapping cast but if you don't have the tools understandable. I'm sure any machine shop would do it for a Lincoln.

 

Hi Jim.  I have a drill press, and can probably find a way to mount the hub to keep it perpendicular, but I think this hub is probably past saving at this point.

[WHX?? 49,189]

ooohhh yup James, that ones toast and demoted to hub puller duty. Whats with the bushing  in ther? 

[TravelinJavelin 620]

2 hours ago, WHX11 said:

This was another boogered up hub but notice where  the set screw is there was good meat yet. This was from me running the tractor with the hub walking.... ...........Since this tractor is no longer a heavy worker I put in the other set screw and . 

yeah I discovered my C-120 hub after I pulled it off looks just like this but much worse and like someone else commented its a on puller duty now also I discovered my drive belt pulley on the trans was loose too tightened that up and and all good there now looking for another hub myself

Edited June 1, 2017 by TravelinJavelin

[JamesBe1 82]

1 hour ago, WHX11 said:

ooohhh yup James, that ones toast and demoted to hub puller duty. Whats with the bushing  in ther? 

 

Yeah, I was wondering about the bushing thingy too.  I've had this since the 80's (2nd owner), so it's probably from the factory like that.  It sure looks like a bushing or sleeve, but then again, it also looks like an outer lip on the casting that just looks like a bushing.  But . . . it makes me wonder: what if someone wanted to bore out a hub and insert a sleeve/bushing, then it would be like new again.  A simple and effective way to reman a hub!

11 minutes ago, TravelinJavelin said:

yeah I discovered my C-120 hub after I pulled it off looks just like this but much worse and like someone else commented its a on puller duty now also I discovered my drive belt pulley on the trans was loose too tightened that up and and all good there now looking for another hub myself

 

How do you make a hub puller out of an old hub?  I haven't run across any stubborn hubs yet, but when the time comes I sure would like to have one handy.

j

[Coadster32 793]

Just a suggestion if you use a set screw at 90 degrees....run the set screw in to touch and mark the axle. Take the hub off, and grind a slight flat or dimple for the set screw to go into/onto. Oherwise, the set screw could/might/will displace material on the axle, and you'll have a hard time taking the hub off again.

[WHX?? 49,189]

Sure now you mention that trick @Coadster32!

10 hours ago, JamesBe1 said:

How do you make a hub puller out of an old hub

Search on hub puller here James and you will see all kinds of neat ways to make one. Just need a shot hub and maybe a trip to a hardware store!

Here's just one of many threads

 

[doc724 925]

One last thing that no one mentioned.  Always use a NEW set screw.  Get a good one, GR-8, not the cheapest you can find.  Also, get a 3/8 8 point socket so you can crank the snot out of that square head set screw.  It is impossible to put enough torque on a 4 inch long 3/8 open end wrench.

[gwest_ca-(File Mod) 11,102]

From the 1979 B, C and D service manual

When tightening the jamb nut just snug it up. Any more than that tends to pull the set screw back out.

 

Garry

[pfrederi 17,895]

12 hours ago, gwest_ca said:

From the 1979 B, C and D service manual

When tightening the jamb nut just snug it up. Any more than that tends to pull the set screw back out.

 

Garry

Second what Garry points out on the jam nut.  Also be especially careful on the jam nut if you have drilled and tapped a second set screw hole.  The factory version has a flat surface on the hub that the jam nut goes against.  Your home made one will not as the hub has a slight taper to it.  if you crank down too hard on the jam nut you can snap off the hardened set screw...flush with the hub.  Some day I will be cursing my self if I ever have to remove the hub I did that on.  (Live and Learn)

[R. L. Addison 299]

I had to take a broken screw out of the "D" series hub & axles I'm going to sell. I also sometimes use a 3/8 drive extension to tighten those set screws as the female end of the extension is a perfect fit over the square head, and the male end is out behind the wheel, easily accessable and much easier on my stiff joints. Ditto for jam nuts.