How much gear oil 72'' tiller

You checked for a piece of post or rock stuck in the tines?

You should be able to turn the PTO shaft by hand. Suggest you disconnect the PTO shaft from the tractor and make sure the problem is the tiller.

The tiller end of the pto shaft has both a slip clutch and a shear pin to protect the gear box and tine shaft drive gear. See attachment.

If you are unable to turn the PTO shaft by hand with it disconnected from the tractor then likely there is something jambed in the tines or internal damage to the gear box or tine shaft gear drive.

Parts diagrams are in the owners manual. Manuals are free download at https://www.kingkutter.com/manuals

take the whole thing apart... Wow and I looked, thats ugly

hello, you have a bad axle seal that needs replacing,replace or keep putting in gear oil,

http://www.kingkutter.com/contact.asp you can input your information and download the manual from there

You can order one here. http://www.kingkutter.com/WholeGood.asp?item=Tiller

most gear boxes have a bottom drain and a side fill plug , you fill until the oil runs
out of the top plug

Caterpillar Yellow is about as close as you will come.

USE SAY A BROOM STICK AND ON THE OUTSIDE ON THE DECK YOU CAN USE IT LIKE A STETHOSCOPE AND PUT IT TO YOUR EAR AND LISTEN TO DIFFERENT SPOTS ON THE DECK TO HELP YOU ZERO IN ON THE CULPRIT .. IF'N I WAS ANY HELP VOTE FOR ME ...THANKS.. JAY

http://www.kingkutter.com/
Perhaps you can find it here? Hope this helps.

If it is leaking around the shaft you can replace the seal.