A friend of my son recently purchased an old acreage that came with this crawler tractor on it. The new owner of the property doesn't want the machine. He says it is a 'Cat', from the '40's or '50's. I'm planning to go take a look. Curious if anyone might recognize the model or have any thoughts...  (It was reportedly running when it was parked--but has likely been some years.)

 

It's an Allis Chalmers. HD6? HD7? Hard to tell the model. Ran when parked eh? Hehe!

"Hehe" is right--but stranger things have happened in the land of the Midnight Sun. If my friend (Yukon Bob on this forum) and I retrieved it, it would be for the challenge and fun of seeing if we could restore it a bit. He has a 1942 Oliver that he is playing with as well.

that detroit will probably start right up but take the pre cleaner off of the air cleaner and have a board that will cover the opening so you can starve the engine of air. just in case the rack is stuck and you have a run away!!! another good precaution is look at the fuel filters to find an air bleed petcock that you can open to also kill a run away. sometimes it takes both and it is good to know and be prepared cause you don't have much time before it grenades.

Really useful advice, Neil, building on Bursitis's wisdom. Will certainly make a video record if things move forward. I'm doing some sleuthing to figure out how best to transport it to my place if we do retrieve it. I was guessing maybe 8000 lbs--but specs say the HD7 is 14k, not counting the blade... I used to have a 14k trailer, but it would not be capable.

another point is make sure the rack does move properly and isnt sticky either.
the only way to shut down a runaway diesel is to kill the compression or starve it of air. turning fuel off often doesnt work as they will run on oil if they are hot enough or simply that flogged out.

i have seen a single cyl hot bulb engine run away, it wasnt fun.

4 grown men hanging off it it walked about 30 ft and turned around and came back, the old fella that owned it tried turning off the fuel it did nothing as it had started running on oil.
apart from another bloke turning up who knew what to do we couldn't shut her down. as this engine had a separate air valve he held it in with a hammer handle till it stopped. this killed the compression so it stopped firing. luckily no one got hurt.

due to having the lp gas torch continuously under its nose to heat it and a faulty governor, the constant heat weakened the fuel valve spring each time the piston went back the valve would suck open adding more fuel and the speed just kept increasing.

once it was repaired properly and a new torch with the proper metering jet for the job was purchased it would run happily all day with only 15 minutes of preheat time mind you this took a while and few more runaway episodes before the old bloke was convinced to fix it properly
well when the club president threatens next time ill stop it with a 12lb sledge hammer you take notice of him.

Here's one prepared earlier.
The engine was finally restrained by tossing the blue rag over the intake reed valve box on the crankcase it would seem--not sure how much help the bloke in the Hi-viz overalls was.
Cheers,
Eddie B.

Back to the original question. I'm not sure about the tractor but the blade attachment is an Isaacson (spelling?). They were a complete piece of shit. Terrible to grade with, undersized pump that would boil the hydraulic oil. The pins and links were not even as big as what you would find on a D2.

This forum is always a fine source of useful intel. I can confirm that the tractor is an Allis-Chalmers HD7. But I was unable to herd the cats to take a look and see about starting on Saturday. So will see if we can get there before winter sets in. Will certainly provide a video of the effort when we get there.