# older Troy Built Horse PTO will not engage



## John Coutu (Apr 20, 2020)

Hi guys, newbie here.
I just purchased an older Troy Bilt Horse from a guy, we went through it all and everything worked. Got it home and it made a couple of passes and the tines stopped turning. Checked out YouTube, adjusted the belt tension and it made it a few more passes and again tines stopped. I found another post and removed the rear tiller and found the pto wasn't engaging. I backed off the set screw and adjusted as much as I could tell and got it to move a little but only enough to make it grind and not engage. I think I am on the right track but could use some advice. Thanks


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## Suribachi (May 5, 2020)

Hi John,
Same issue here. The PTO spins freely on the main shaft which makes me think the key is sheared or missing. I removed the retainer clip in the main shaft that holds the clutch on but I can't remove the clutch, sounds like it is hitting something. Have you had anymore luck figuring out what is causing your issue? Did you remove the dog clutch and if so any issues doing so?
Thanks,
Bill


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## Steven J. Novak (Oct 10, 2020)

Hello guys...
Pardon the pun but "...I've been beating the same old Horse...".
I bought my Troy-bilt PTO horse roto tiller. brand new in 1984. It has been a worthy piece of equipment for many years. 
A brief history: purchased in 1984. I kept it stored in our attached garage. I later moved all our mowers and garden equipment to the barn and still out of the weather. I rarely used it since about 2005.
Here's the issue... the tine PTO is stuck in the "disengage" position. No matter what I try I can't get it to budge. I removed the hood and tine shaft and everything there works as expected (nothing stuck or jammed). Looking inside through the hole where the 2 cogs line up there appears to be enough lube grease on the "dog clutch". The internal assembly is not visible through this hole. With the "forward/reverse" and the "Fast/slow" levers both in neutral, I spun the shaft by hand with the front pulley. I can see the dog spins as expected. I tried holding the dog from moving when spinning the pulley and they both turn together as they should. I can't slide the dog on the shaft so I can't be sure if it's stuck on the shaft or the mechanism that moves it is stuck or jammed. This internal mechanism is neither accessible through the gearbox nor the hole the tine shaft cog goes through. So I guess my real question is how do you access that internal mechanism to manually inspect/repair it? It seems as if this is a "big secret" I can't get any info on it. The Mfg's provided Owner's manual and parts diagrams reveal very little at best. I sure could use some help.
Thanks
Steve...


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## Bob Driver (Nov 1, 2017)

Take a look in the manuals section of this forum. Look for the "Troy-Bilt Horse Master Parts Catalog". It's a parts manual, but there is some really good text detail as to how the drive train works on the old Horse Tillers. It's been downloaded quite a bit, so it's apparently pretty useful. It's pretty good for what's available on-line


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## Steven J. Novak (Oct 10, 2020)

*Bob Driver*... First I would like to thank you for responding to my inquiry. 
I opened the Troy-bilt Master Parts Catalogue file to which you referred in your response. I also looked through all the other files referencing anything to do with rotary type tillers. If anyone asks my opinion of these... yeah, they are all real pretty and have a lot of listed parts and pretty pictures.
Unfortunately not one of them show anything to which I have been seeking information.
Since I have disassembled a good portion of this machine I have no photos of what I'm referring. I will have to reassemble most of it and try to provide some pictures in another post. I'd like to repair this myself if possible. Also being an old geezer (72), I'm on a fixed income, don't drive anymore and can't really afford to purchase a new one and chuck this one out. It's also difficult to come up with several hundreds of dollars to have some other joker do the same thing I am capable of doing if I locate the right information.
Stay tuned for for subsequent post.
Thanks 
Steve


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## Bob Driver (Nov 1, 2017)

I run into the same thing trying to fix something with electrical schematics. All those different colors and squiggly lines.....

OK.... Go back to the manuals section. I just posted "TROY-BILT HORSE TILLER TRANSMISSION SERVICE MANUAL". If you can't find and fix the problem with that Service Manual, you could be in over your head. That's the Factory Service Manual from Troy-Bilt and the most detailed repair information you're going to find.


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## Steven J. Novak (Oct 10, 2020)

Okay then... I took a few pics to try to help explain what I have been talking about. I assembled them in power point and reconfigured to a PDF. 
BTW... the transmission manual PDF you suggested in your last post appears to be the same as one of the manuals that came with my tiller in 1984. There again the diagram shows a direct drive straight shaft from the engine to the tines. The housing looks to be one complete cast piece. This one I have separates just behind the gearbox thus the need for a PTO engage disengage mechanism located there.
Assuming it will post properly... The top left pic shows the "Tine PTO Clutch" indicator tag and lever, and then a pan out view of that picture. Below that a pic showing the cog on the end of the removed tiller tine shaft attachment and where it connects to the gear box casing. Large pic to the right is a close-up of the "Dog clutch".
Explaining further, The Tine PTO lever is attached to what the Parts Catalog refers to as the "tines/pto clutch lever eccentric shaft" that comes through the side of the casing from the inside because there is a threaded bushing and a retaining ring holding it in place from the outside. Also the internal end of the shaft has an "ear" 90 degrees and perpendicular to the shaft. Attached to that with a cap screw is a lock washer and a small ball bearing. This shaft and bearing assembly may or may not be the problem. Then again it could be the "dog clutch" which I assume slides forward and backward perhaps no more than 1/2 to 3/4" in order to engage the matching tine shaft cog. I'm trying to figure out how to get at this assembly. The "hole" that the tine shaft end goes through is perhaps 2" in diameter. When I had the gearbox cover off I used a long probe and slid it along the inside wall if the gearbox to feel for an opening. None found. the gearbox is sealed on the ends with retainer rings, bearings and oil seals. I can't tell if the small housing detaches from the rest of the gearbox. But it is likely it doesn't. It would have been a big help to myself and probably many others if Troy-bilt would have included a footnote explaining this. It's most likely something stupid that I'm just not seeing or understanding.
Any other thoughts or ideas? 
I'm still baffled. These are the things that drive people to drink.
Thanks once again...
Steve


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## Bob Driver (Nov 1, 2017)

Either your eccentric shaft has seized where it passes through the case bore bushings, or the sliding clutch is seized on the square key at the end of the main shaft. The eccentric shaft comes out of the back of the main case on the left side and attaches to the short lever that engages the tines. It passes through the case bore in what appears to be a big nut with 2 bushings inside the bore and there is a 90 degree arm on the end. There is a pin that engages a groove in the sliding clutch on the end of the main shaft. There's a snap ring on the end of the main shaft that retains the sliding clutch. The clutch dog slides on a 3/16 x 1" square key at the end of the main shaft.

Be very careful with trying to free that eccentric shaft, don't just grab it and twist with a pair of vise-grips. It's a 1/2 shaft, easy to break, and it's $100. It passes through what looks like that big nut on the outside of the case that has 2 bushings in it. That's where it usually seizes. Try slowly loosening the big nut to free up the bushings on the eccentric shaft. Slowly working the nut back and forth as your loosening it is usually enough to free the shaft in the bushings. Once again..... *BE VERY CAREFUL*, that little shaft is $100. Once the nut is backed completely out of the case, the sliding clutch dog should be able to slide back and forth on the main shaft. If not, the clutch dog is seized on the 3/16' key. See link below....

Big nut --- Part # 27
Bushings --- Part# 28
Eccentric shaft ---- Part #29
Sliding clutch ----- Part #34
3/16x 1" Key ---- Part # 35

https://tb.shankslawn.com/oemparts/a/trb/5b76e20b87a866138cb44f79/power-unit-transmission-assemblies


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