'68 12F Grader (Hanna) control box issue

Fat Dan said:

Well shoot, I have to gear up to take my son's airstream to the lower48. So doing anything more to the graders is going to have to take a back seat till I get back.

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Travel safe! Roads south in BC may be impacted by the flooding and landslides a couple of weeks ago. You should check BC highway info. Happy to try and connect when you pass through Whitehorse.

FYI, had Hanna out plowing today. -20C, but no issues. Used my propane space heater in the cab and, other then having to deal with frozen condensation on the inside glass, no problems with dog clutches. So feeling pretty good.

Onfoot said:

Travel safe! Roads south in BC may be impacted by the flooding and landslides a couple of weeks ago. You should check BC highway info. Happy to try and connect when you pass through Whitehorse.

FYI, had Hanna out plowing today. -20C, but no issues. Used my propane space heater in the cab and, other then having to deal with frozen condensation on the inside glass, no problems with dog clutches. So feeling pretty good.

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I'd like to stop and tell some lies but ..Ua first lire don't have a chance so you start.

Well, I'm generally around. And that's the truth.

56wrench said:

Hey, is that rh rear wheel hub loose on the axle shaft? By the black around the axle nut it may indicate the nut is not as tight as it should be. There should be a locking tab on the washer under the nut

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Well 56wrench you rang the bell, hit the bullseye, hit the nail on the head .... What I'm trying to say is the large nut on the rear hub WAS LOOSE. It gets dark by 3:00 o'clock and had other fish to fry so I did not get a chance to examine the nut, drive key or clean nor tighten yet. It took me half a day just to find where my son put my large wrenches. My wife and son loves to put my tools where they are convenient for THEM to access. LOL I NEED A SHOP TO LOCK MY TOOLS. Ever since my wife started watching DIY shows somehow all my tools became hers. Why, I don't go rummaging through her purse and use up all her lip gloss n eye liner and then not tell her about it or put some stuff in another purse because I think it's more convenient.
Nuff to peeve off the pope I tell ya...

Thanks for letting me vent ... LOL I'm having fun now...
Should I have started a different topic to talk about the hub nut?
Anyway took the nut off and cleaned and examined the key and axle the best I could. The "Locking Washer" has been flipped (several times) and is not in the best of shape (more ovalish than round at the locking key tab ... see pic) I assume that is way the nut came loose. I think I can fix the locking washer by welding some on the key tab and filing/grinding it back into shape. The key itself has some wear that can can be seen from the end of the axle shaft but the key is still squairish and the cut in the axle shaft. There was enough room to put a .020 shim next to the key. Temp fix till I can get up next to the tools.

I can't find a torque spec is it like wheel bearings ... preload the back off and retorque to spec?

Nope, just tighten it on. Its like any other tapered, keyed shaft. I couldn't find a spec for it but probably in the neighborhood of 600 to 800 lb ft. Then smack the end of the nut with a 5 or 10 lb hammer and check it again. Do that a couple of times. It looks like it had been loose for a while. Next spring or summer you may want to pull the hub off and check the taper and clean any rust off before reinstalling. Most often they come loose because they weren't installed tight enough or the hub and shaft weren't cleaned properly before reassembly. Also the end of the shaft should be down inside the hub by about 1/8". If its flush with the edge then it will never stay tight. I have a trick for that if that is the case.

I was walking the dog last night and realized how dumb the question of preloading a tapered shaft was DUH. Thanks
I couldn't find a toque spec either so I thought I would wait until I received a response. Again Thanks ... I measured the hex size on the nut and it is 2 7/8" across the flats (p/n nut V-168) (lock 8F8049) (washer 8F8050) (key T-217) (seal 4B4529). Need a socket ) O' yeah, new tool)
The hub and axle are flush. You have an Ol' trick to recess the shaft in the hub?

Update both rear drivers looks like the nuts may be loose. I have that old dark oil mark on both sides that 56wrecch noticed around the axle nut in the video. Thanks Everyone

The hub should be pressed on at 20 ton and the nut at 350 lbft.
Yours looks like its past that point.
Let the cobbling commence.
Bob

Thanks Bob. I have four PhD's and two Master degrees in Cobbling.

So, what i have done on some tapered shafts that have that issue(as long as there is about 1/4" clearance between the back of the hub and the bearing housing) is to make a thick washer on my lathe about 1/4" thick and machine out the backside about 1/16" to 1/8" deep but leave the outer edge at 1/4". That way when it is tightened on it will allow the shaft to protrude outside of the hub slightly but still be tight. You have to be careful to make sure you have adequate thread engagement in the nut. You don't want to be peeling the threads out of either. What size are the threads on the shaft? 1 1/4" maybe? 800 lb ft may be too high. My #12 serviceman's handbook doesn't give a spec. I just made a tool out of a piece of pipe about 4' long with a piece of 3/8" plate welded to the end with a hex hole cut in it. Mine hasn't come loose in 30 yrs. You really only want to change the shaft(axle) as a last resort although a good hub may fit better on the worn shaft

56wrench Thanks again...
Bob (Bluox) said 350'lbs after a press of 20t. I think your idea will work as long as the seal holds up (100 years or forever or whichever comes first) Where is the axle and hub wore making the hub and axle flush? You mentioned different hub on a worn shaft; I take it the hub and axle are the wear points and we are just tiring to see how much more life we can squeeze out of this puppy? Good plan so far.

Thanks it took me a bit but I think I have a game plan now The information you provided has been very valuable. I wouldn't have even known about this problem if you hadn't alerted me to it ... truly Thank you
I thought I had some good ideas before but I have been wrong before too.

Changing the shaft seal is not as simple as you would think. It goes in from the back side of the bearing retainer so you have to pull the retainer assy off the tandem housing to do it which likely means having to loosen off the drive chain first, which may be time-consuming if the eccentrics are seized. If that particular chain is loose enough, you may be able to remove the bearing retainer assembly without loosening it. Your two loose hubs are likely on the rear axles because originally those were the only two wheels with brakes. On the 8T machines, brakes on the front drive axles were optional. So, somebody in the past likely had them off for brake work and didn't get them tight enough. On the axles with brakes they are more likely to come loose because of the added back and forth torque when the brakes are applied over a few thousand hours of use.

Fat Dan said:

56wrench Thanks again...
Bob (Bluox) said 350'lbs after a press of 20t. I think your idea will work as long as the seal holds up (100 years or forever or whichever comes first) Where is the axle and hub wore making the hub and axle flush? You mentioned different hub on a worn shaft; I take it the hub and axle are the wear points and we are just tiring to see how much more life we can squeeze out of this puppy? Good plan so far.

Thanks it took me a bit but I think I have a game plan now The information you provided has been very valuable. I wouldn't have even known about this problem if you hadn't alerted me to it ... truly Thank you
I thought I had some good ideas before but I have been wrong before too.

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The hub and shaft are not a wear item until they are ran loose.
Thats why the hub is pressed on the shaft and the nut keeps it on.
At this point what ever you can do to keep it from working will help.
Bob

Thanks guys for your help ... this could have been really expensive. !!⚡Experience is Expensive⚡!!
The 8T came with a 9K. I looked in the corresponding parts manuals and the drums and hubs are the same part numbers. The axles I have not look them up yet, nor do I want to change them anyway.

Fat Dan said:

Well shoot, I have to gear up to take my son's airstream to the lower48. So doing anything more to the graders is going to have to take a back seat till I get back.

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Fat Dan said:

Good eye 56wrench ... Thanks !!!
Went down today and looked at the wheel hub nut on the Right Rear Driver. It has been broken lose the locking tab has been reused. The dark area around the hub nut is dry and the nut dose not look as tight as it should be. The hub nut looks as though it has a slight gap between the nut and washer and another small gap between the washer and the hub, I cannot spin the nut with my hand. Either hub nut is not to toque spec or there may be dirt between the mating surfaces. All the other hub nuts and locking washers on the rest of the rear axles are still panted and undamaged - looking tight.
I don't have a toque spec, LOL, in all these books
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Well geez I almost wish that r/r wheel was loose on one of my customer’s 112 graders. That side brake is plugged off on his machine, and he wants to get it fixed. I’m hoping the hub isn’t too tight on the axle shaft. I thought I could take things easier when I retired!