AC 720 / Simplicity 9020 Rear PTO Hub
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Garden Tractors
Forum Description: A great place to discuss the Simplicity and Allis Chalmers Garden Models
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=142013
Printed Date: 23 Feb 2025 at 8:38pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: AC 720 / Simplicity 9020 Rear PTO Hub
Posted By: rustydollar
Subject: AC 720 / Simplicity 9020 Rear PTO Hub
Date Posted: 31 Aug 2017 at 5:18pm
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Thought it best to give the rear pto hub a thread of its own. The 3D cad work more or less completed, the fellow who did the work is unsure of the correctness of the internal involoute spline. Originally I was going to send my rear hub to the EDM shop, my Hub has some wear on the spline so the EDM shop suggested that I sent the shaft instead. Told him the shaft was still installed in the transmission, he then offered to cut a sample spline to mail out to me for fitting. I like his style, but have decided to remove the shaft from my transmission then send it over to him so there are no mistakes. While the shaft is out I'm going to order new bearings for the re-installation. The hub will be machined using an alloy of 4140, same stuff used to make twist drill and axles, our new hub will be better that the original. While I'm on the topic of transmissions, what did the Allis and Simplicity use for hydraulic oil.  |
Replies:
Posted By: rustydollar
Date Posted: 31 Aug 2017 at 8:05pm
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To remove the rear pto shaft from the transmission, remove the top cover, pick the front seal out then remove the internal snap ring. Bring the shaft forward then remove the bearing, with the bearing removed you can now withdraw the pto shaft. The rear bearing is needle bearings, I'm not replacing the rear bearing only the front one along with a new seal.   |
Posted By: rustydollar
Date Posted: 31 Aug 2017 at 10:04pm
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Anyone considering to replace the rear hub that hold the electric clutch to the pto shaft leading into the transmission. Should remove the pto shaft for a visual inspection, after removing the shaft found that the splines are also badly worn. The worn splines I'm hoping can be tig welded over with new splines cut in. It's in the hands of our EDM fellow with more knowledge in this type of repair. This is the type of worn out junk you'll get from eBay. Combine that wear with that of the hub and you have some serious wear.  |
Posted By: coggonobrien
Date Posted: 01 Sep 2017 at 5:01am
| nice |
Posted By: aras
Date Posted: 01 Sep 2017 at 7:11am
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Very nice! I love this fix! They use ATF for hydraulic fluid
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Posted By: talntedmrgreen
Date Posted: 01 Sep 2017 at 11:56am
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great thread, thanks! can't wait to see the rest. ------------- Patterson B1*B1/B1Forklift*B10*BigTen/B1Loader*B110*B208*B206*616*Homelite T16H/T8/T7/RM7E*Landlord/Loader/Trencher*Broadmoor717*Serf525*2110*7790*Legacy XL*Twin 20*Squire9*Squire6*JCPenny 494 |
Posted By: rustydollar
Date Posted: 01 Sep 2017 at 12:36pm
Definitely not an overnight fix and not for the feint of heart with shallow pocket books. The shaft will have to be machined from new stock, the gear is welded onto the shaft the weld will be machined away saving the gear for the new shaft. The shaft splines cut in on a milling machine using an indexing head, once completed the gear will be welded onto the shaft. As for the hub the main profile shaped on a cnc lathe, then shipped over to another company that does the EDM to cut in the internal spline. Some of the quotes I've received are outrageous, I'm still shopping for a decent price and I'm running out of shops. With the economy going the way it is wouldn't surprise me that well be forced to call on 1-900 numbers billed per minute asking for a quote.  |
talntedmrgreen wrote:Posted By: rustydollar
Date Posted: 01 Sep 2017 at 12:37pm
Thanks, just wanted to confirm. |
Posted By: rustydollar
Date Posted: 07 Sep 2017 at 8:40pm
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The pto shaft uses a weld on gear, the weld will be machine off then the gear pressed off then re-welded onto the new shaft. Splines on the new shaft are milled in on a milling machine using an indexing head. Once the hub has been machined the spines are cut in with EDM. Total cost for both parts came in well under a grand. |