So what are the lead washers under the head nuts REALLY for?

Have you ever removed a head and saw one or two studs with rust on the shanks? A stud can leak at the block side, and the coolant can travel up the shank inside the little bore and make it all the way to the head cavity. Or, if the cylinder head gasket weeps any fluid into the stud area those lead washers are the last seal there is before meeting up with the oil in the valve area.

I really think they were used more to seal than for lubricity. Everywhere else you torque a true nut surface down against a true head surface and call it a day. With a horizontal engine and the coolant laying there 24/7 against the head and studs, and the studs in through holes into the water jacket, for the price of a few lead washers they were sure it was sealed, and the torque application was smoother. So few people torqued those heads during field repairs that many just judged that when they had squished most of the lead out they were pretty much close to shop applied torque value. And, they probably were.

JMHO

Frank

Ben

Go to Google & enter the seven letters of jdparts, and the first entry to come up should be something to the effect of "jdparts homepage". That is the one you want. Enter your address data, and the setup sequence will select the JD Dealer nearest to you. Then -- any time you need something from your dealer, scout it out on the site first and price it. Then when you actually buy, if the price is violently different -- you have basis to question it. Remember -- the fellows working that counter may never have touched a tractor like yours much less be at all familiar with its parts, and errors can be made. (PatB)