# JD850 not turning over



## lbran18 (8 mo ago)

Hi All 
I have a 1987 jd850 that was rebuilt a few years back with a new head, it has only 43hrs on it sense overhaul.
I was using the tractor to move some things from building to the next when all of a sudden it went to squealing and shut off. Now it will not crank nor will it BAR over. It was running fine with signs of going to fail me at all.


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## bmaverick (Feb 20, 2014)

lbran18 said:


> Hi All
> I have a 1987 jd850 that was rebuilt a few years back with a new head, it has only 43hrs on it sense overhaul.
> I was using the tractor to move some things from building to the next when all of a sudden it went to squealing and shut off. Now it will not crank nor will it BAR over. It was running fine with signs of going to fail me at all.


Your JD850 is a Yanmar YM2500 in JD green paint. 


Check the engine oil.
Check the oil filter. If clogged, the suction would squeal and the engine 'could' shut down.


Clean the radiator screen and the fins.
Clean the air intake and the re-usable air filter. Engine would squeal when the air filter is clogged and 'will' shut down.

The engine would still run if in Neutral should the hydraulic filter clog up.


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## BinVa (Sep 21, 2020)

I’m sure the engine has cooled down by now… I’d see if you can turn the engine by hand. You’re not giving a lot of information. Did the sound come from inside or out of the engine…above or below. Did it sound metallic or belt squeal? Could be a frozen alternator or seized crank or rod bearing. B.


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## lbran18 (8 mo ago)

bmaverick said:


> Your JD850 is a Yanmar YM2500 in JD green paint.
> 
> 
> Check the engine oil.
> ...


Thanks for your response, I replaced oil and filter, replaced/cleaned air filter. So I also tried using a 36” 1/2” breaker bar and can not turn the motor by hand. After setting a few days I tried to crank with key again and motor turned over about 3 revaluations and then stopped turning. While it was turning over it made the squealing noise again. It sounds like it came from mid to rear of engine. Was thinking maybe trans shaft binding on pilot bearing/bushing but not sure?!? What’s your thought on that?


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## lbran18 (8 mo ago)

BinVa said:


> I’m sure the engine has cooled down by now… I’d see if you can turn the engine by hand. You’re not giving a lot of information. Did the sound come from inside or out of the engine…above or below. Did it sound metallic or belt squeal? Could be a frozen alternator or seized crank or rod bearing. B.


Yes mid to rear of engine, Was thinking maybe trans shaft binding on pilot bearing/bushing but not sure. I took the belt off as well and still can not turn engine with a 36” 1/2” drive breaker bar.


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## Fedup (Feb 25, 2014)

Wrong guess. A seized pilot bearing might tie the flywheel and clutch/transmission input shaft together, but it wouldn't create any sort of noise until you try to stop the shaft while the engine is running. Your problem is deeper than that. 43 hrs or not, you're going to see the inside of the motor before you're done.


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## HarveyW (Sep 15, 2014)

Drain the engine oil looking for metal particles in the oil. Then drop the pan to see what the problem is. And before you start further tearing the engine apart, check parts availability. I read on the internet that engine parts are not available.


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## lbran18 (8 mo ago)

Fedup said:


> Wrong guess. A seized pilot bearing might tie the flywheel and clutch/transmission input shaft together, but it wouldn't create any sort of noise until you try to stop the shaft while the engine is running. Your problem is deeper than that. 43 hrs or not, you're going to see the inside of the motor before you're done.


Yeah kinda looking that way. Thank you for your input


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## lbran18 (8 mo ago)

HarveyW said:


> Drain the engine oil looking for metal particles in the oil. Then drop the pan to see what the problem is. And before you start further tearing the engine apart, check parts availability. I read on the internet that engine parts are not available.


I drained the and didn’t have any metal particles in the oil nor on the magnet drain plug. The oil was still pretty clean but a little dark. My next step will be dropping the pan i guess.


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## BinVa (Sep 21, 2020)

Not sounding good… you should be able to get a good look around once you drop the pan. You mention the rebuild… what was the reason? And was it in frame or out? How many total hours on tractor not counting the recent work?


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## lbran18 (8 mo ago)

BinVa said:


> Not sounding good… you should be able to get a good look around once you drop the pan. You mention the rebuild… what was the reason? And was it in frame or out? How many total hours on tractor not counting the recent work?


I bought this tractor about two years ago, the man i got it from said it was getting water in the oil and said the head was cracked and replaced it with a new head and in frame as well. I have all the paper work from the rebuild as well. He spent over $5,200 in parts. The total hours on tractor are 3364 
it was rebuilt at 3321. It’s been a great unit with issues till now.


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## bmaverick (Feb 20, 2014)

lbran18 said:


> I bought this tractor about two years ago, the man i got it from said it was getting water in the oil and said the head was cracked and replaced it with a new head and in frame as well. I have all the paper work from the rebuild as well. He spent over $5,200 in parts. The total hours on tractor are 3364
> it was rebuilt at 3321. It’s been a great unit with issues till now.


Are you located in the southeast? Most of the parts are available in that region of the country. Fredrick's and Hoye. Both are OE Yanmar and will same you the Deere markup pricing on the 3T80 engine rebuild parts. 

If you live elsewhere, then Weavers' Compact Tractors has the rebuild kit. The bearings are sold separately because of how much wear is on the cam and the connecting rod/arm to the piston. They come in a few sizes to compensate. 

Yanmar 3T80J Engine Rebuilt / Overhaul Kit - 0 - John Deere Compact Tractor Parts 

Sounds like the original rebuild was for the top end. 

I had a JD850. When the engine went, it was due to a poor diesel mechanic who rebuilt it wrong. I shopped around for a used 3T80J, but none were found till I found Fredricks. For the cost of a full engine rebuild, just a mere $1,000 more got a totally restored OE Yanmar YM2610 based on the JD850. And the bonus was, the PowerShift.


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## BinVa (Sep 21, 2020)

Until you get inside and look, it's a guessing game. If the engine was squealing, I lean towards oil related bearing failure. Could be a main since it wouldn't have been replaced during an in-frame, but I suspect a rod bearing or 2. A reputable rebuilder would have checked the crank and sized the rod bearings accordingly. Was the oil pump replaced? Had you noticed low oil pressure readings lately? Hopefully I'm way off base!!


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## lbran18 (8 mo ago)

bmaverick said:


> Are you located in the southeast? Most of the parts are available in that region of the country. Fredrick's and Hoye. Both are OE Yanmar and will same you the Deere markup pricing on the 3T80 engine rebuild parts.
> 
> If you live elsewhere, then Weavers' Compact Tractors has the rebuild kit. The bearings are sold separately because of how much wear is on the cam and the connecting rod/arm to the piston. They come in a few sizes to compensate.
> 
> ...


So after looking at all the paper work for the rebuild everything was replaced from 
Cyl head, rings, rod bearings, pumps (water, oil, hyd, etc) looks like they did not replaced the main bearings. All parts were bought through Hoye. I will tear down next week once i get the 63 int Scout done this weekend. At this point i may get a new crank and bearing kit…
thank you for your help and once i get in the engine i will keep you posted as to what i find!!


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## lbran18 (8 mo ago)

BinVa said:


> Until you get inside and look, it's a guessing game. If the engine was squealing, I lean towards oil related bearing failure. Could be a main since it wouldn't have been replaced during an in-frame, but I suspect a rod bearing or 2. A reputable rebuilder would have checked the crank and sized the rod bearings accordingly. Was the oil pump replaced? Had you noticed low oil pressure readings lately? Hopefully I'm way off base!!


So after looking at all the paper work for the rebuild everything was replaced from 
Cyl head, rings, rod bearings, pumps (water, oil, hyd, etc) looks like they did not replaced the main bearings. All parts were bought through Hoye. I will tear down next week once i get the 63 int Scout done this weekend. At this point i may get a new crank and bearing kit…
thank you for your help and once i get in the engine i will keep you posted as to what i find!!
only has a light for oil pressure, has new oil sensor in it and it has never come on. Temp always ran 150-170 never higher. It has always ran so well and never gave a sign of having any issues or up coming issues. We only have 4ac with a 72” finish cut and a 4’ rake that i used to do raking with. I’m going to rebuild again if needed..


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## bmaverick (Feb 20, 2014)

lbran18 said:


> So after looking at all the paper work for the rebuild everything was replaced from
> Cyl head, rings, rod bearings, pumps (water, oil, hyd, etc) looks like they did not replaced the main bearings. All parts were bought through Hoye. I will tear down next week once i get the 63 int Scout done this weekend. At this point i may get a new crank and bearing kit…
> thank you for your help and once i get in the engine i will keep you posted as to what i find!!
> only has a light for oil pressure, has new oil sensor in it and it has never come on. Temp always ran 150-170 never higher. It has always ran so well and never gave a sign of having any issues or up coming issues. We only have 4ac with a 72” finish cut and a 4’ rake that i used to do raking with. I’m going to rebuild again if needed..


Do you need the service manual? Or do you already have it?


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## lbran18 (8 mo ago)

bmaverick said:


> Do you need the service manual? Or do you already have it?


I have one from Hoye, I will dig it out and look it over because I don’t remember if it had all the specs in it. If not you have one for sale or know where I can get one with the torque specs?


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## xxxjd950xxx (May 11, 2017)

lbran18 said:


> I have one from Hoye, I will dig it out and look it over because I don’t remember if it had all the specs in it. If not you have one for sale or know where I can get one with the torque specs?


You have the later 2nd generation of the 850 and you will want the TM1192 Technical Manual by John Deere.


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## xxxjd950xxx (May 11, 2017)

lbran18 said:


> I have one from Hoye, I will dig it out and look it over because I don’t remember if it had all the specs in it. If not you have one for sale or know where I can get one with the torque specs?


At this point it couldn't hurt to remove the hydraulic pump in case it is seized and see if the engine will turn over. Easy things first.


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## lbran18 (8 mo ago)

xxxjd950xxx said:


> At this point it couldn't hurt to remove the hydraulic pump in case it is seized and see if the engine will turn over. Easy things first.


will try that.. its new but that don't mean anything either!! thanks for your response


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## bmaverick (Feb 20, 2014)

lbran18 said:


> will try that.. its new but that don't mean anything either!! thanks for your response


It's not hard to split the tractor, just time consuming. With it split, you will indeed know if the engine is the trouble or the hydraulic system. Plus you can inspect the clutch. 

Hoye has a great vid on how to split these Yanmars/Deere compacts. Look for the clutch plate replacement vid. Aaron does a good job with it.


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## lbran18 (8 mo ago)

bmaverick said:


> It's not hard to split the tractor, just time consuming. With it split, you will indeed know if the engine is the trouble or the hydraulic system. Plus you can inspect the clutch.
> 
> Hoye has a great vid on how to split these Yanmars/Deere compacts. Look for the clutch plate replacement vid. Aaron does a good job with it.


yeah I've spilt them before, we have a few here work I had to put clutches in but I have never heard this type squeal that I had when she shut down. I really thought it was the alternator or water pump, so the first thing I did was jump off and pull the belt and restart but that was a big no. so then I tried to Bar it over by hand and I could not budge it at all. so a couple of days/week later I said hey lets try it and see? she turned over 3 times with the same squeal and stopped again, ang again I tried to bar it over and no luck. so I will pull pump and if that does not work I'll pull pan and look there. from there I'll pull rod and main. pray its something simple!! if y'all can think off anything else i will keep checking in to see what kind of input folks have! again thank you for your responses!


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## lbran18 (8 mo ago)

bmaverick said:


> Are you located in the southeast? Most of the parts are available in that region of the country. Fredrick's and Hoye. Both are OE Yanmar and will same you the Deere markup pricing on the 3T80 engine rebuild parts.
> 
> If you live elsewhere, then Weavers' Compact Tractors has the rebuild kit. The bearings are sold separately because of how much wear is on the cam and the connecting rod/arm to the piston. They come in a few sizes to compensate.
> 
> ...


sorry forgot to mention I'm in north Florida... Suwannee County


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## bmaverick (Feb 20, 2014)

lbran18 said:


> sorry forgot to mention I'm in north Florida... Suwannee County


On I-75 & SR93 in FL, there is a long bridge that is Suwannee River. I always wondered if that's where the old song came from. hmmmm

Old Folks at Home - Wikipedia


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## Fotoguzzi (Jan 12, 2020)

🍿


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