3 cyl John Deere 820 starter help needed.

[mrmikey]

The battery is good at 12.7V at the starter

That doesn't necessarily mean the battery is good. You could get 12.7V out of 8 "D" cells but that doesn't mean that there's any amperage available. What's the voltage drop to when you attempt to engage the starter?
Any way you can bar the engine over to make sure it's not hydro-locked by something leaking into the combustion chamber?

 

[fullchoke]

What I'm hoping for is to knock it off it's bad spot kinda like beating on it might. If it cranks just an instant it might start then in 12volts, and I can move it to work on it in a better spot. I parked it where it is because there is no covered area for it, and it is covered with a tarp next to my cabin. The wind blows hard and often there so the shelter from the cabin helps keep the tarp from shredding, and sun off the tarp, but it's a bad place to work on it especially if I need to remove the loader.

Mikey, I didn't put a meter on the battery, but I did turn on the lights, and they only flickered when the starter solenoid clunked, they didn't dim.
There is a yoke at the front of the engine that runs the hydraulic pump. I put a socket extension thru that and the engine moved easily.

 

[mrmikey]

There is a yoke at the front of the engine that runs the hydraulic pump. I put a socket extension thru that and the engine moved easily.

Good show, perfect.
Did you try using an auxiliary battery or the one in it and using a set of booster cables one clamped to a good ground right at a cleaned spot on the starter and the other directly to the positive terminal of the starter. bypassing everything, solenoid, safetys etc? Tapping (not beating the crap out of it, the magnets are quite fragile) the starter whilst doing this. Make sure it's in neutral

 

[fullchoke]

Mikey, I like your idea. Being there by myself, I would tap, then walk around to the other side of the tractor to push the starter button, to get the clunk. That evolved to using the wood end of a 5lb hammer, giving it a solid rap. I'll tone down the blows. The hydraulics for the loader prevent access from the right side, so I had to walk around each try. By having power at the time of the tapping could make a big difference. In my experience with starters, once you have to resort to tapping them, the number of times that works is very limited. I just need it to start one more time! If 12 volts doesn't work 24 will be next. The tractor is about an hour away. I'm now going to be delayed until next weekend before I can try this. Thanks

If anyone has tried to remove the starter from a John Deere 820 that has a JD 37 loader attached please speak up. If you had success or found out it can't be done, it would be good to know either way. Thanks

 

[zzvyb6]

We took a 37 loader off using forks from another tractor. Had to triangulate the chains because of the odd center of gravity.

Could you come up with another hydraulic supply and latch it into the loader circuit? With weight in the bucket, the arms with raise up and you can back away from it.

 

[mrmikey]

If 12 volts doesn't work 24 will be next.

Unfortunately if the starter is indeed on a bad spot with no conduction, it wouldn't matter if you connected 120V to it.

 

[MTGreen]

Unfortunately if the starter is indeed on a bad spot with no conduction, it wouldn't matter if you connected 120V to it.

If the starter is in a bad spot with no conduction and the solenoid is working, you should theoretically be able to actuate the solenoid to engage the ring gear and starter gear, then use a socket to move the engine in reverse slightly which would in turn move the starter off the bad spot against the one way bearing in the Bendix gear.
The big downside here is depending on design not all starters can have the solenoid disconnected electrically from the starter motor, so if it's not disconnected doing the above will result in the starter motor suddenly getting conduction and the engine trying to start while you've got a socket on the crank bolt which obviously is not OSHA-friendly...

What about pull starting it in reverse and just dragging the bucket? I've never tried pull starting a tractor before is there any reason that won't work? Alternatively pulling the tractor in reverse while in a forward gear and engaging the starter solenoid should have the same effect as above with a socket but in a somewhat safer scenario

 

[mrmikey]

....the same effect as above with a socket but in a somewhat safer scenario

I'd be nervous of using that approach...not saying I wouldn't do it but nervous, good way to get a power bar in the gums LOL.

 

[fullchoke]

Thanks guys for the ideas. I don't have another hydraulic supply, or room to get another machine near it except from the rear. I do have a JD 855 I could haul 60 miles to pull it out of it's spot, but that's not my 1st choice. It could end up being my only one. I could then tow it out of there, but I didn't think I could tow start while in reverse, very well.
I thought that with increased voltage, it might bridge a wider gap in the starter with 24.
I will look at the starter again to see if the power can be disconnected from the solenoid to it. I remember the 2 posts one on the solenoid with a cable running to it from the battery, and one on the starter next to it. I may be able to disconnect the lead from the starter post. I would need a helper to hold the starter button. I wouldn't want the starter to crank the engine with the socket extension prying inside the yoke that I used before to move the engine. There isn't a nut that I can put a socket on. If there was, the ratchet could take care of a sudden movement, but I'd still be nervous. Looking at the front of the engine, does anyone know which way it rotates while running? I think it's clockwise, but not certain. That would be very important.

 

[Uncle_Charlie]

You mentioned putting new terminals on the cables, and unless I missed something, you are still running the old cables. I've had cables that went bad and steered me toward a new starter. I saw the same symptoms that you see. Nothing worked until I swapped out the cables.