# My JD 726 may finally have to be put to rest.



## dagolfnut (Feb 19, 2014)

The drive sprocket is stripped out and spins freely on the drive shaft. Not a good thing when the part is NLA, no longer available. Anyone have any suggestions? Sources for used parts?


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## 94EG8 (Feb 13, 2014)

Any picture of the sprocket in question? Good pictures and chain type would be helpful.


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## Waterlooboy2hp (Nov 29, 2011)

94EG8 said:


> Any picture of the sprocket in question? Good pictures and chain type would be helpful.


=====================================

I think he is looking for this. --- John

AM38108 | eBay


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## dagolfnut (Feb 19, 2014)

Waterlooboy2hp said:


> =====================================
> 
> I think he is looking for this. --- John
> 
> AM38108 | eBay


That's close, but not quite it. The part number is AM33116.


If I can figure out how to insert a picture I will do it.


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## Shryp (Jan 1, 2011)

Can you drill a hole in it and put a bolt through it or does it slide back and forth?

Actually, welding would be quicker and easier...


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## dagolfnut (Feb 19, 2014)

Shryp said:


> Can you drill a hole in it and put a bolt through it or does it slide back and forth?
> 
> Actually, welding would be quicker and easier...


The drive shaft is a hexagon and sprocket slides on it. A bolt or roll pin already occurred to me. I'd only have one forward speed, and no reverse, but it might get me through the winter.


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## 43128 (Feb 14, 2014)

you could try taking it off and tapping holes in it, but without putting them in all the way, that way they just slide over the hex shaft but are not permanently installed


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## 43128 (Feb 14, 2014)

and locked in one position


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## Shryp (Jan 1, 2011)

To add on to 43128's idea, maybe if your hex shaft is long enough you could consider rigging up something to the end of the gear like part of a wrench or socket or some other hex shaped piece of metal. Could probably cut part of the gear off if needed.


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## dagolfnut (Feb 19, 2014)

This is the great thing about these types of forums. You're drawing a blank for a good solution to a difficult problem. So you ask the question and in short order someone posts a good idea for solving your problem. I think that a appropriately sized, cut off socket welded to the side of the gear may just solve my problem. I guess I'll find out this week end.


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## Shryp (Jan 1, 2011)

Awesome. Be sure to come back and let us know how it works out.


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## countryboymo (Oct 13, 2014)

There are extra long deep sockets that could be chopped and a weld shop could drill or cut a whole in a suitable gear with a plasma cutter. I know hex key stock is available and sleeves if you do some creative searching.


Bushings, Ball Nuts, Collars, Bore Reducers, Sleeves, Shafts, Tolerance Rings Look for the hex hole sleeve.

If it is just the gear that is worn out any farm and home type store or napa and most auto parts stores can get generic gears. A friend with a welder and decent metal working skills can rebuild that and have it run straight and true without tremendous hastle. Weld shop or machine shop would be like new.


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## countryboymo (Oct 13, 2014)

I also put a search in at 777parts.net to see if there is one in hiding


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## dagolfnut (Feb 19, 2014)

Well I was up the creek but I found the paddle! So things are beginning look better. My initial assessment of stripped was incorrect as you can see. I have to assume that forty years ago when this was made, the hexagon sleeve was pressed into the bushing the gear is welded to. There is no key-way/set screw, etc., to lock the two parts together. I'm not sure I can have this welded in place, it keeps weeping oil/grease onto the paper it is sitting on. If nothing else the link that countryboymo posted does have a sleeve available of the correct size.


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## Kiss4aFrog (Nov 3, 2013)

Where did you end up on this one ??

It looks like there is enough meat there you could drill and install two set screws.

A machine shop might be able to knurl the outside of the insert so it's a really, really tight press fit.


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## YSHSfan (Jun 25, 2014)

It may be a self lubricating bushing that was originally pressed on but over periods of time got loose.

This would be my approach on it, I hope it makes sense:

1. Take a _centre punch_ and make a series of marks along the entire surface (like for starting to drill holes) on the outside of the bushing as well as on the inside of the gear, this will sort of increase de diameter of the bushings and decrease the diameter of the gear.
2. Install the bushing on the gear (they should fit snug).
3. Make 2 centre punch marks and drill 2 holes (using 5/32"drill bit)180 degres apart from each other right in between the gear and the bushing.
4. Run a tap on the holes just drilled (#10x32 tpi) not all the way thru, so that the stus or screw would set in place ounce they reach the end of the threads.
5. Insert 10x32 long set screws or long regular screws and cut or grind the heads off. (this would keep the parts from separating, but also keep them from rotating one from the other). 
6. Now you have a good reusable sliding gear.

Note:
1. If you have enough material you could use 1/4'x28 set screws (7/32" drill bit) or 1/4"x20 set screws (13/64" drill bit).
2. It is very important that the holes and the tap threads are as straight as possible.


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## YSHSfan (Jun 25, 2014)

This is an example of the how to centre punch it, and the finished repair. This one has 4 set screws, i think in your case you only need 1 or 2.
Also when centre punching it, I would do the bushing only and try it, if it is snug enough to keep it together i'd move on to drilling and threading it, if it is not snug enough then centre punch the gear.

Outside








Inside








Finished repair.


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## dagolfnut (Feb 19, 2014)

Thought I'd post an update on my broken 726 gear. I ended up having the 2 parts brazed together, nothing else I tried worked. I have about 6 hours of run time on it since the repair so just maybe I'm good to go.
Thanks for everyones advise, there are some pretty good ideas here.


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