John Deere A pistons

JD Bob · Nov 11, 2013

I have a set of john deere pistons that I took out of a john deere A of mine and they read a1240 on one side and gep on the other side and I think they are aluminum does anyone know what size bore they are for and will they be the originals?

Paul from MI · Nov 11, 2013

I think all the original John Deere pistons for As were cast iron, so most likely aftermarket high compression pistons. Standard bore for an A is 5.500". Aluminum pistons require a bit more clearance than cast iron, so will be around .010" smaller. Various oversizes are available and you can figure out if they are oversize by miking them. The distance from the wrist pin to the face of the piston will tell you if they are in fact high compression pistons. What was the serial number of the tractor they came out of? What is the width of the ring grooves, some were 1/4", some were 3/16".

Earl-IL · Nov 11, 2013

Genuine Parts , Now Clevite A1240 alum. gasoline. The oversize was stamped on the face. .045,.090.125. Hasting has rings.

John Deere A pistons

JD Bob

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Paul from MI

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Earl-IL

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