Flywheel seized

IdahoNative

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Equipment
Kubota B7100D 4x4, non-HST, FEL 1630
Jan 12, 2022
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Florida, central
Recently purchased a B7100D. I replaced every fluid, it does not burn oil and the radiator stays full. I put about 36 hours on it. I was back-dragging sand in low, just crawling along. Heard a loud "snap" that appeared to come from the front right side of the engine. But I had hearing protection on, so who knows. It instantly shut down. No other noises or smells. Turn the key, and "thunk". Removed the starter and tried to rotate flywheel with a prybar. It didn't move. I can push it forward and backwards in any gear (all have the same level of resistance, not much) and the flywheel doesn't move.

I have no idea where to start. Since the flywheel doesn't move and I can push it, does this mean the problem is in the clutch or rear differential?

EDIT: Since I heard a "snap", I looked in the sand where it died. I found what looks like a phillips head adjusting screw within a hard plastic sleeve. Anyone recognize this...
 

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kubotafreak

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GRAND l6060, L3560, B6100, gr2100, tg 1860, g1800, g1900, g2160
Sep 20, 2018
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Try spinning the crankshaft. With someone holding the clutch disengaged. There is small bolts on the snout that you can put a prybar on, or the pully counter weight vs the frame.
 

IdahoNative

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Equipment
Kubota B7100D 4x4, non-HST, FEL 1630
Jan 12, 2022
114
46
28
Florida, central
Try spinning the crankshaft. With someone holding the clutch disengaged. There is small bolts on the snout that you can put a prybar on, or the pully counter weight vs the frame.
Thank you for the reply.
I will give that a try. I think it has a front PTO, can I try to spin it there?
 

kubotafreak

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GRAND l6060, L3560, B6100, gr2100, tg 1860, g1800, g1900, g2160
Sep 20, 2018
1,019
372
83
Arkansas, US
Thank you for the reply.
I will give that a try. I think it has a front PTO, can I try to spin it there?
Yes,
That is where the three bolt heads are. At least this will isolate engine or trans hopefully.
 

Mark_BX25D

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Bx25D
Jul 19, 2020
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Yes, you really need to stop focusing on the flywheel and find out if you can spin the crank.
 

IdahoNative

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Equipment
Kubota B7100D 4x4, non-HST, FEL 1630
Jan 12, 2022
114
46
28
Florida, central
Yes, you really need to stop focusing on the flywheel and find out if you can spin the crank.
Yes, you really need to stop focusing on the flywheel and find out if you can spin the crank.
Before I try turning the crank, does the diesel motor need to be decompressed? Kinda like removing a spark plug or two on a gas motor/
EDIT: Mark, never mind my question. I found a thread that said if my B7100D doesn't have a decompression lever, just crack the injectors open.
 
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Tx Jim

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M7040 HDC-1,JD 4255,Ford 6700
Apr 30, 2013
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I think with no compression release mechanism one would need to remove glow plugs or remove injectors to ease engine cylinder compression for manually turning crankshaft
 
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kubotafreak

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Equipment
GRAND l6060, L3560, B6100, gr2100, tg 1860, g1800, g1900, g2160
Sep 20, 2018
1,019
372
83
Arkansas, US
I think with no compression release mechanism one would need to remove glow plugs or remove injectors to ease engine cylinder compression for manually turning crankshaft
You can still spin them manually with a good leverage spot. They just have more compression than a gasser. You just will have to do it slower and let some compression bleed off as you go.
 
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Mark_BX25D

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Bx25D
Jul 19, 2020
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It's not hard to crack the glow plugs. Just back them out a few threads until they are loose. No need to completely remove them.
 
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GeoHorn

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May 18, 2018
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I doubt that little screw has anything to do with the problem…. the break on the collar/screw assembly is not a fresh break… it’s rusted and has lain in the sand for quite some time.
 
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