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'68 12F Grader (Hanna) control box issue

Onfoot

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Joined
Dec 1, 2020
Messages
63
Location
Whitehorse, Yukon, Canada
Occupation
Retired
Was looking forward to taking Hanna out to clear our first dump of snow for the year. I let the circulating heat pump warm things up for a couple of hours (it being -18C / 0F). She started without issue. But there was a 'wop/wop/wop' noise coming from something in the control box and it broke the shear pin. I replaced the shear pin and re-started her, with same result.

"Hmmm," I wondered... "Could it be related to being cold?" It was -31C / -24F yesterday. But last winter that had not been an issue. Anyway, I let her run with the cab heater on long enough to take the chill out. Then I shut her down and replaced the shear pin and restarted. This time no 'wop/wop/wop" noise. But then I raised the LH side of moldboard. It raised without issue, but when I released the lever back to neutral, there was the wop/wop/wop noise for just a bit, and then it stopped. I then raised the RH side--same thing, but this time wop/wop/wop and silence--the shear pin sheared. I repeated this a few more times, with same results on every control lever. Sometimes the noise would stop. But the next lever would create the noise again and inevitably the pin would shear.

I have the service manual, but cannot find any trouble shooting description of Hanna's symptoms. I have a sinking feeling that I'm going to need to dissemble the control box. I think the front can be removed to see what might be going on.

Way out of my depth on this, but such is life. Grateful for the wisdom of the forum community. I do wish it had happened in the summer, mind you. Working outdoors this time of year is tedious. (Thinking of you, Fat Dan!) Ah well.
 

56wrench

Senior Member
Joined
Dec 4, 2016
Messages
2,074
Location
alberta
I would check for ice in the control box. Next, i would heat the entire box with a herman nelson and drain the oil and see what comes out. Lastly, i would put lighter oil in the control box for winter use
 

Onfoot

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Joined
Dec 1, 2020
Messages
63
Location
Whitehorse, Yukon, Canada
Occupation
Retired
I would check for ice in the control box. Next, i would heat the entire box with a herman nelson and drain the oil and see what comes out. Lastly, i would put lighter oil in the control box for winter use

Thanks, 56wrench. I'd be surprised if there's ice, but then again... But you have described my plans. In reviewing the operator/maintenance manual, I found fine print that says in temps below 10F (and we were at 0F yesterday) up to 1/4 of the control housing oil can be thinned with kerosene. The specs ('68, mind you) call for 30W oil. So I will heat it up, drain it, and refill with Red Line MTL 75W80 synthetic (which is described as "Satisfies the gear oil viscosity requirements of 75W, 80W and motor oil viscosities of SAE 30, 10W30 and 5W30). It is used for manual transmissions and diffs in cold climates and I think may serve well in the control housing.
 

Coaldust

Senior Member
Joined
May 9, 2011
Messages
3,287
Location
North of the 60
Occupation
Cargo Tanks, ULSD, RUG, Methanol, LPG
Generally speaking, I’m not sure you will see a cold-weather viscosity improvement by switching to a 75w-80. I would be inclined to use 15w-40 synthetic engine oil in the control box this winter. Mo betta viscosity index. Maybe even 5w-40. It would be interesting to compare the spec sheets.

But, ain’t nobody got time for dat. It’s -17F this morning and my customers are busy melting their starting systems, exploding frozen batteries and doing bad things with starting fluid. Time to cash in on the mayhem, boys! Big bucks fixing those frozen trucks!
 

Onfoot

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Joined
Dec 1, 2020
Messages
63
Location
Whitehorse, Yukon, Canada
Occupation
Retired
Sounds a bit like where I live, Coaldust! But you didn't mention folks using tiger torches to warm their engine blocks and coming back to find a smoldering heap of melted plastic and etc... :)

Here are specs from Amsoil 5W30 and Red Line 75W80. Note especially their pour specs at -50C

Red Line 75W80:
upload_2021-11-22_13-17-42.png
Amsoil 5W30:
upload_2021-11-22_13-18-46.png

They look quite comparable re. viscosity. And I am inclined to think that the gear oil has additional helpful properties... In effect, relative to viscosity, they are both 5W30.
 

Onfoot

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Joined
Dec 1, 2020
Messages
63
Location
Whitehorse, Yukon, Canada
Occupation
Retired
Amsoil 26 Nov 21.JPG Genset 26 Nov 21.JPG Cab warmer 26 Nov 21.JPG Parked again 26 Nov 21.JPG Update on Hanna and the control box. Today I was able to warm the control box on Hanna and change out the oil. I used my little propane space heater to warm the cab and another propane radiant heater to heat the exterior part of the control box which I had covered with a tarp to hold in the warmth. It drained without issue. I then added 4.5 gal. of Amsoil 5W30 Series 3000 HD diesel oil. (After speaking with several oil technical folks, the Amsoil product looked to be a suitable lubricant for the application, and it was available locally.)

I then fired Hanna up without issue and there were none of the control box symptoms. All controls worked flawlessly. So my previous symptoms seem clearly have been dog clutches not working with congealed oil.

Feeling considerable relief, I was able to do a plowing run on my road. I think in the future when I need to run her in serious cold, I will use the little space heater. It worked really well. Photos of the day's work attached.
 

56wrench

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Dec 4, 2016
Messages
2,074
Location
alberta
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
 

Onfoot

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Dec 1, 2020
Messages
63
Location
Whitehorse, Yukon, Canada
Occupation
Retired
Nice work ... Problem solving ... how many hundreds of liters did the control box take?;)
:eek:16 gallons (60.5 liters) in the tranny on my 8T n 9k:eek:
Got the 9K home finally come on by and take a look

View attachment 249763
Control Box takes 4.5 US gallons of oil--18 Amsoil quart jugs, in my case. :)
The rear axle and transmission took 13.5 gallons or 54 quarts.
 

Fat Dan

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Joined
Jan 14, 2020
Messages
175
Location
Alaska
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

I will run down and take a look later ... thanks for the heads up. Yeah they both need a lot of work but that is why I got them to help keep me out of this dang chair. Not a good thing when your rear tire and hub pass you as your going down the road.
:eek: First thought.
o_OSecond thought .
:oops: third. :mad: $$$ parts :(Now I got to fix it
thanks again for the heads up...
 

Fat Dan

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Jan 14, 2020
Messages
175
Location
Alaska
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
Snapshot1.jpg
Snapshot.jpg
 

56wrench

Senior Member
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Dec 4, 2016
Messages
2,074
Location
alberta
You will have to remove the nut, clean the threads and reinstall it and see if it tightens on farther. Also, when its off, remove the washer and look in at the drive key and see if its still intact in its place and not sheared
 

Fat Dan

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Jan 14, 2020
Messages
175
Location
Alaska
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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