IH 300U Engine Noise

Dellbertt

Member
All original. Starts easy, runs smooth no smoke. I use it for snow plowing.
Last couple weeks it has developed a front lower engine noise/knock when under load.
When pushing easy it is smooth and quiet. As soon as it starts pushing hard a loose noise comes from lower right front of engine. It is a definite knock but with a slight ring to it. It is not upper tappet rattle. Sounds like one cylinder to me but I am not a internal mechanic. I changed the oil and filter and added a half qt. Lucas. It quieted some but is now back to where it was before the oil change.
What is it and is it ok to drive it under no load.
 
I would be real scared it might be a broken rod cap bolt or a main bearing cap bolt. Running it longer could cause great damage. I would pull the oil pan and inspect the lower end of the engine. The International utility tractors ran at 2000 rpm while the Farmall rowcrops with the same engine ran 1750, and the H/Super H ran 1650. I've seen too many of those engine blocks with holes busted in them.
 
I have a 300U that I bought with an engine knock. Turned out that the bolts had come out of the front axle support where it bolts at the back of the oil pan, allowing it to push up against the oil pan, and bend the oil pan enough that the crank would hit it, creating the knock. I could feel the knock in the front axle. It would go away when I jacked up the front end.
 
A couple years ago I had a 300u to work on with engine knock, it had been overhauled by ag department at a vocational school, after pulling the pan one rod was discolored, pulled cap and found bearing spun in rod, cap was on backwards, to my surprise the crank was fairly smooth and little wear, good thing it was a gasser, put it back together and its still running
 
Thanks for the replies. Kind of figured it needed tearing into. Will leave it set till I can pull the pan.
Thanks,
Dell
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top