IH 684 engine locked

Hi All! My 684 was running just fine, I parked it for a week and when I went to start it it seemed as though the engine was locked. I thought it must be the starter so I had it rebuilt but it still does the same thing. When I try to turn it over it makes a loud clunk like the engine is locked. If it is, I don't understand why. It did not get hot and there is the right amount of oil in it. Anyone have any ideas as to what the problem might be and how to fix it?
Thanks,
Ernrod

Pull the spark plugs. Try to turn engine over by hand with the front fully or fan. If no joy maybe pulling the starter and using a large screwdriver to push flywheel via the starter ring. Sometimes putting it in high gear and rocking back and forth will move the engine for you.

If engine id free that is a good start!
J

(quoted from post at 19:54:25 04/28/15) Pull the spark plugs. Try to turn engine over by hand with the front fully or fan. If no joy maybe pulling the starter and using a large screwdriver to push flywheel via the starter ring. Sometimes putting it in high gear and rocking back and forth will move the engine for you.

If engine id free that is a good start!
J

Click to expand...

It is a diesel, I'll try rocking it.

Hi Ernrod, a few things to think about: DO NOT TRY to pull start the tractor or more damage could occur.
Have to determine if it is engine or from clutch rear ward that is causing problem.
Engine quick checks:
1) Were there heavy rains with muffler uncovered or rain cap blown open to allow water into cylinder?
If it is water in the cylinder then by removing the starter and using a pry bar you should be able to rotate the engine
backwards.
2) Check coolant level is it down more than normal?
3) Loosen fan belt in case it is seized alternator or water pump?
4) Remove the clutch inspection plate under the bell housing and see if nothing has jammed between ring gear and housing.

Clutch, Transmission, rear end and PTO and hydraulic pump drive

I am sure you tried to start tractor with clutch pushed down as there is a clutch safety switch on the clutch.
If you can't rock the tractor then with other wheels chocked, jack up one wheel off the ground:
With Rev/Hi/Lo lever in neutral see if you can rotate the wheel.
Next with clutch depressed an tractor in 4th HI see if you can rotate wheel in both directions.

One other possibility in the rear end is the PTO drive shaft that is directly connected to the pressure plate and drives two
hydraulic pumps if the tractor has a T/A. If no T/A then just the main hydraulic pump.

JimB

Thanks Jim! I'll try all these things tomorrow if I can find the time. I'll keep you posted as to what I find.

Well! Darned if I can figure out just what was wrong. I went out and bumped the starter a few times while watching the fan and noticed that it moved maybe a 1/4 inch each time. So I kept doing it and finally it stated very slowly turning and then finally went around fast enough to start the engine and when it did a big mouse nest blew out of the air cleaner. Is it possible that it was air locked somehow?
At any rate now it starts first crank as usual and purrs like a kitten. Thanks for the replys.
Ern.