I've got a problem that goes back to last summer and has come back to my garage floor yesterday. This John Deere G110 deck loves to throw it's belt, but not consistent. I have changed the belt and idler pulleys. Unit will run fine for two to three weeks and then starts throwing the belt. Will do it multiple times. Neighbor brings it over and I check it out, can't find cause, send it back and it will work fine for another two to three weeks, then repeat the problem. I have tested it myself, have thrown the belt, but I can't find a cause. Happens most often when engaging the PTO, but will also jump off during operation. I have checked the spindle pulleys, looked for sticks or twigs on the deck, tensioner spring looks good, and jackshafts look to be running true. Unit is about seven years old and I have done all the service on it. he brought it over yesterday and said " do what you need to do, so we don't have the problem this summer". I don't want to throw parts at it, but I know that I must be missing something, probably something small or stupid. Anyone have any suggestions as what to look for or had this problem come up. I don't have much hair left, but if I can't figure this one out, I won't have any.