I picked up a Roper PHD today. I have a lot of limestone close to the surface here, so it's probably not going to be digging the holes for my next pole barn, unfortunately. I have some spots in the fields/pastures where it'll get put to work though.

I think it's mostly there (unfortunately the parts books I have don't cover the post hole diggers at all) with the exception of the handle, which is a homemade deal that I presume was done to allow the weights to be hung on top of the gearbox. I guess I got two WD/WD-45/D-17 rear weights out of the deal, too.

The auger tapers from ~10" at the bottom to ~12" at the top... I presume that makes this a 10" auger? The gearbox isn't frozen up at least.

I thought it was neat that enough of the decals are legible to make out "MADE FOR" above the Allis-Chalmers logo, and "BY ROPER..." underneath.

NEAT !!!

I have zero use for one on my ittybitty lot, but can appreciate your 'find'. My back hurts just LOOKING at them weights so please be careful....

so... 12" originally.

A clever welder could add hardweld to the cutting edge but,hm, 10-12 is 2 inches, so 1" edge is a LOT of weld.. sigh

it sounded better before I started typing..

hmm maybe new augers will fit ??

Dad tried that on one we had YEARS ago.  After God knows how many hours, welding rod, electricity, it still didn't work worth a crap!

sigh, but it sounded so good as I was typing.... nice easy, rainy day job.

sounds like a new auger is the better solution,providing they're all the same direction...

..unlike certain Chrysler wheel nuts......

Otherwise, as Steve says, it's easy to cut down with a torch or plasma cutter.  Main thing is to have a good wear edge, on the bottom...

There is no shear pin holding the auger on and how it is attached was not readily apparent when I looked earlier. I dug around and found this old thread:  https://www.allischalmers.com/forum/roper-posthole-digger_topic24654.html" rel="nofollow - https://www.allischalmers.com/forum/roper-posthole-digger_topic24654.html

So it looks like I would need to remove remove the cutting head on the bottom, and then the auger is keyed to the shaft out of the gearbox. I wonder if I can even find any off the shelf replacement auger that will fit. I think most are shear pin drive as you guys have mentioned. I will do some more digging on the internet but the only option might be to find a replacement NOS one (ha!) or cut off the flighting and weld new on.

Before I do all of that I will probably give it a try as-is and see if I can live with it. If it'll even dig much around here, I can probably clean out a few holes by hand. It would still be better than digging them 100% by hand like I am now. I don't have hundreds of holes to drill but I probably have 2 dozen or so corner posts I'd eventually like to replace.

Brandon

Only thing I can see is the bolt holding the u-joint on the PTO shaft to the input shaft for the gearbox. It would definitely be nice to get a PDF or paper copy of the manual to make sure it has the right hardware there, if it is indeed intended to function as a shear bolt.

The gearbox itself has almost no play between the PTO shaft and the auger, which surprised me.

I have gotten a few requests for this.  The File is too large(7MB) to attach.  The Knowledge forum won't let me post.  I will be glad to send the file to any orange hole digger. The AC's don't have reverse on the PTO.  If you let it go down too fast in wet ground, you have just installed the world's largest drywall screw.  You have to disconnect the Pto shaft and turn it backwards till it lets loose.  If you divide your age by 2 and multiply by the square root of the number of cuss words you use in the first hour, you will have a fair approximation of the number of hours you should expect this to take.  (dave@richardswv.com)

  I have post hole digger for my WD 45 but it just fasten the lift arms and don't have the snap coupler attachment . Used it to put up 2 pole building 1- 28' X 56' and the other 34' X 28' other than had to sharpen points on auger it do a good job. Don't have all them weights on top of it.

Hey Tom, sounds like you have the #10 PHD, improvement over the

roper model.  I was impressed till I saw where you live.  I grew up in Clyde.  You can dig post holes there with a spork.  LOL. 

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Here's a cross section of the gearbox and auger for anyone that's curious. You'll note it's a very different design from most of the modern augers that are just pinned to the output of the gearbox... Which makes finding an off the shelf replacement auger probably impossible. If a guy needed to refurbish one, cutting off and welding on new flighting might be the only feasible option for these?

PS Item 22 is labeled a shear pin. Mine has been replaced with a bolt over the years. I suppose I ought to replace that with the lowest grade bolt I can find and step up from there if it shears too easily, since I don't know what material the original pin was made out of.

I'm new to this forum and I don't know much about the Roper PHD, but it sounds like a cool piece of equipment. Too bad it won't work for your pole barn project, but I'm glad you'll be able to put it to use elsewhere. As for the auger size, it sounds like you're right that it's a 10" auger. It's always fun to find old equipment with legible decals and logos, especially when they have a connection to well-known brands like Allis-Chalmers.

Also, have you ever looked into http://https://upet.com/drilling-rigs/" rel="nofollow - mobile drilling rigs ? They're another option for drilling holes in tough terrain or near surface rocks. They can be a bit pricey, but they offer a lot of versatility and mobility.

 I am pretty sure these were made from 1930s designed ford differentials, because the bearings are ford differential bearing from this era was made by Timken 18-4221. The old ones I am replacing are Timken 18-4221 with the fork logo on them. Also the differential looks just like the gear case on my roper post hole digger. 

Thanks for letting me join and ask questions. I have it apart right now and can post a ton of photos if anyone is interested. 

I would also suggest starting a new post with your question. Might get better answers.

Good luck