No backhoe on this one, but it's either this forum or Old Iron. A 304 is similar to a ** 50 with shuttle shift, two right pedals, one forward, one reverse. Massey Ferguson 304 Industrial tractor with Perkins 4 203 engine has a clunking or light knocking sound that is once every ten seconds at idle, goes away at faster than idle speed. My guess is something is floating around in the torque converter? it seems to be in the area of the sound. Any other guesses, or has anybody actually seen this before?
Dont know if this would apply to yours. I had a 30B that had a knock it sounded like it was coming from clutch. After tearing down to check clutch i found out it was pump mounts in transmission.
Thanks, I'll have to dig into a manual at least and see if this is worth fixing.