I'm back,, After removing the chain I took it to Miller Bearings here in Ocala and after they inspected the chaiin I was asked why I am changing it....I informed them that I was experiencing, what I thought was the cain jumping the sprockets....causing a loud bang when loading out of a bank, stock pile or digging with any degree of force applied to the forward motion of the machine....The loud bang was happening mostly when pressure was being applied to left side steering stick... Sometimes to the right side also but mostly on the left side...After opening up the machine there seemed to be, what I thought was, a good deal of chain droop. The thought was that there may be excess chain length....they stated, based on the chain condition, that they would advise me not to change the chain..We decided to shorten the chain by removing two full links and inserting a master link along with a 1/2 link...therefor shortening the overall length of the chain by 1/2 link....One major question for all you folks now is " What size chain is OEM size for a 642 skidsteer?" I was informed some months ago that the chain should be size 80.... This Diamond chain that I removed from my machine is size 60...There is a 60SH stamped into the side plates of the links....I need to know if the proper size is 80 or 60....Your experience on this fix would be greatly appreciated.... Have fun, buckshot