If it is creeping in neutral with the lever engaging the drive train it is an adjustment. If it is creeping backwards un-engaged it is vibration from the engine.
ALWAYS keep extra shear pins around.......
Welcome to the forum....
C
This message was modified Mar 2, 2005 by ChrisS
Honda 928TA, Ariens 924 STE, Toro single stage S-620, 95 Jeep Wrangler with a 6 foot Fisher Plow, many shovels, one 14 year old boy. Craftsman 01 1000 LTX pimp Gold LT 20hp Briggs OHV V-twin. Tough as it is ugly.