help with mother-in-laws 4010 propane

Sister-in-law and her significant other came down to visit my MIL. They borrowed the 4010 for a while to load up some stuff to haul back to their home.
They came down and said it wasn't running right. Pulled it down to the lp tank and put in some propane. And put in maybe 3 quarts of oil in the engine. Went back to what they were doing and came back down and said it still wasn't running "right". Parked it.
This is all info from my MIL.

I went out today to do some things with the tractor.....loading things to haul off, leveling ground, etc.

The tractor would not turn over. Took off the battery and gave it a quick charge.

Still wouldn't turn over. Acted like it was locked up.

Got MIL to pull me a little ways with the pickup to see if I could get it started. Tried 7th gear going maybe 6 mph. Would slide the wheels about a foot before MIL and the pickup would quit pulling.

Pulled flywheel inspection plate off. Put in prybar to rock it back and forth. Not locked up but wasn't really easy to move either. Could not use the fan and pressure on the fanbelt to move the engine.

Pulled sparkplugs. All looked fine. No water in the cylinders.

Tried to use the starter. No go.

Got tired....decided to try the intertubes......

Where to from here????

Could it be the front hydraulic pump????

Or galled crankshaft bearing?

Or just a bad starter?

Please help......MIL needs a loader tractor.....:^)

Maybe they put in a whole lot more than 3 quarts? Maybe hard to tell with a propane, but often a locked up engine will be full, with very clean oil!

Try 8th gear.

I tried 8th gear....same as seventh. Didn't want to break anything....just trying to see if I could get it to turn over.

If I can rock it back and forth with a pry bar at the flywheel, should the starter be strong enough to turn it over???? And why wouldn't it turn over when I tried to pull it....

Something just doesn't make sense to me......but keep the suggestions coming......MIL on fixed income. :^)

If engine won't turn over when towing tractor in 8th gear especially if spark plugs are removed I think engine pan needs to be removed & crankshaft brgs checked for galling.

Quote:

Sister-in-law .... They borrowed the 4010 .... They came down and said it wasn't running right. Pulled it down to the lp tank and put in some propane. And put in maybe 3 quarts of oil in the engine. Went back to what they were doing and came back down and said it still wasn't running "right". Parked it. This is all info from my MIL.

Engine was ran to long with little to no OIL pressure...???

Remove oil pan.......?

Remove Valve Cover......?

Any auxiliary Oil pumps that may have failed / Seized..?