An index of Hendricks County probate order book volume 40 (covering 12 March 1918 - 13 December 1918) has been added to the Hendricks County GenWeb site. Entries in order books are very brief and merely summarize what happened each time a probate case came before the judge. They are meant to be a glimpse of the kind of information you may expect to see in detail in the probate packet (aka "loose papers").
Hendricks County's probate order books volumes 1 through 43 (covering 1825-1921) have been microfilmed. That microfilm is available locally at the Plainfield Public Library, as well as at the Indiana State Library in Indianapolis and by ordering through the Family History Library in Salt Lake City, Utah.