Post hole digger from auto differential

   / Post hole digger from auto differential #1  

nuvz

Bronze Member
Joined
Mar 30, 2002
Messages
52
Location
Laramie, WY
Tractor
Yanmar 2010D
I posted this question on the Yahoo site a while back & thought you all might enjoy it,I know I did!!

Post Hole digger out of Automotive Differential - I wrote:
"Has anyone ever made a posthole digger using an automotive differential as the auger drive? Looks to me as if it would work. What do you think?"

Responses:
Pretty sure it has been done... I think you have to weld up the ? spiders ? or something ? to get it to put power to the auger after it hits resistance.. check with some of the old farm/welding books for information on it.. they were big on using old rearends for stuff....

I think thats what alot of them are built out of that you buy.

welding the spider gears on a differential makes it so that both wheels spin at all times, when u have an open differential (not welded) when one tire (or auger) does not have any torque ( it free spins) then the other tire will also not have any torque, it will not spin, that is why on older cars with say 2 wheel drive, only one wheel will spin when u get stuck. i think that u will need to weld the spiders if u want to make a differential into a posthole digger. If u want instructions on how to do it i would be happy to help. also do u need down pressure on your 3 pt. hitch to use a posthole digger? also, how can u all down pressure to a tractor that does not have it, like on my 53 ford 601? thanks for your help, and if u need help with welding spiders, e-mail me at coonboy888@hotmail.com

Down pressure is NOT a requirement on digger.

The answer to your question is YES, and I am the guy who did it.
The biggest problem is coming up with a U joynt with enough travel that it won't lock up.
Completely cut one axel housing off the punkin, weld cover in place of axel tube, and shackle mount there to suspend rear end.
I also made a single flite augur from the removed axel shaft. By facing off the hubs of both axels, they bolt together to make an augur with a capacity to drill almost 5 feet deep.
It is necessary to weld the spider gears. It's also a good idea to determine witch half to cut off to get the auger to turn in the right direction if you already have an augur you intend to use.

I once used a automotive differential for a winch. We left the drum-brake assembly on one side and added the winch drum to the other. It was driven off the PTO. We had a tag line to the brake master cylinder so you could walk a hundred feet from the bulldozer with the cable/tongs and tag line and winch logs anywhere you wanted them. It worked GREAT!
With this type of setup you have full control of the speed (slipping the brake) and operation. Better'n that, you don't have to weld anything inside.

Would you be interested in a picture of one. I have a digger built by my uncle back in the 30's out of a differential for a tractor before the 3 point ever came out. It has a square shaft that slides inside if the spider gears to allow digger to go up and down, also lets you have down pressure to make it dig.

Do we want to see a picture.. what a silly question... go get your camera now ! giving the 3 pt downward pressure would be a matter of changing the up down hydraulic cylinder from a single acting (one hose going to it) to a double acting (one hose for in and one out)...... downward pressure SHOULD not be required ,,, but if you make the auger with the spiral the wrong direction or don't figure out which side of the differential turns the proper direction you are going to need a LOT OF DOWNWARD PRESSURE ,,,, LOL,,,to make a hole ,,,,,,,,,I would like to know how you made the flight on that auger,,, that seems like a hard thing to make.... On the angle of the ujoints.... you might try some of the "double " ujoints that some cars used at one time... Like Lincoln.... when they were trying to give as much foot room to the passengers... they were heavy but I think they give a lot more angle capacity...Greg

How to Make Auger Flite:
1, cut circle of 1/4" plate to diameter of augur
2, make cut from center to edge of circle along radius line.
3, Put bending die in hydraulic press
4, bend plate along radius lines to make it look liea an augur flite
5, cut out center hole for diameter of augur shaft
6, Weld flite to augur shaft
7, hardsurphace cutting edge
8, kiss [censored] at the Cat shop for junk bucket teeth
9, Cut old teeth down to size
10, Weld teeth to lower edge of augur
11, weld old lag screw to tip end of augur shaft
12, Bolt augur shaft to shaft coming from differential half.
13, Drill a few test holes when nobody is around to watch.
14, Drill holes for new barn poles, try to not look too conceipted and accept complements.
15, answer questions on why you only built a single flite augur with "It works much better in red clay"
16, Buy beer for the guy who owns the Sterling digger so he won't tell everybody you wers too lazy to bend up 8 flites.

Actually, single flite augurs work better on 3 point setups because the upper flites don't bind in the hole as you go deeper. You just need to lift and clear more often.
 
   / Post hole digger from auto differential #2  
Yup, I told you how to build it, step by step, so have you finished yours yet?
 
   / Post hole digger from auto differential #3  
Boy I would sure like to see some pics of the digger and winch.
 
   / Post hole digger from auto differential #4  
I still have my printed copy of the 'recipe' for the post hole digger that was back from the Yahoo Club. And, as luck would have, there was a complete axle layin' for a year in the weeds just down the road! Well, that's another project that's yet to be done. And I read tonight on TBN about a cement mixer mounted on a differential. Hmmmm. I wonder if there's another axle layin' around somewhere? All these neat projects.......never enough time....
 
   / Post hole digger from auto differential #5  
mrcaptainbob

Do you have a link to the TBN differential/cement mixer? I'd like to see more information or hear from anyone who has done this. I've got an old cement mixer and easy access to differentials. Sounds like a great project.

Mike
 
   / Post hole digger from auto differential #6  
Actually it was posted by the same NUVZ as who started this post. It's under PTO sement mixer dated 5/10/2002. There's some darn good posts in that string. I sure do like this TBN! Thanks, by the way, NUVZ. I still have the copy of what you wrote when we were a Yahoo Club. I really enjoyed that recipe! Most concise and descriptive piece I've read about building a machine like that, and done with humor besides.
 
 
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