Note:In 1995 the E4OD pump was redesigned to utilize pump gears with 10 lobes on the outer gear.
Prior to 1995 the outer pump gear had 11 lobes. The pump casting was also revised. Prior to 1995 the pump casting was designated as E9 or F1.
Beginning in 1995 the casting designation was changed to F5 and is currently F8. The E9 and F1 E4OD pumps suffered from low pump output and
should be replaced with an F5 or later model pump: