Hi folks, I need some advice before I go spending a ton of money.
I've recently purchased my third IH/Farmall, a 68 544 gas gear drive. It has developed a slight knock and I'm trying to figure out if it's valve, piston, or crank/bearing related. I changed the oil, old oil came out dark but no shavings at all. Put in straight rotella 30 with a bottle of lucas oil treatment, Fram filter. Knock is most noticeable at idle and goes away as you increases RPM. I unhooked the #1 plug wire and the knock goes away completely. The knock sounds higher in the engine. Any advice or relative experiences will be greatly appreciated. Ehere should i start? Different oil? Should I rebuild? Pull the head? Pull the pan? Thank you.