this is the second time this happened. the ring on the pto side turned and the piston needs to be replaced again. what would cause this little pin that holds the ring from turning to move. it looks like it is physically drove off to one side of the piston, like the ring is pushing it until it disappears. has anyone ever seen this and what would be the cause? i am thinking crank????????

i could use some advice on this problem>

mabye check cly clearance how many mile do you have on sled.?

it has 5000km on it and it seems that the pin was pushed around the piston by the ring, thats what it looks like, the tracks in the groove on the piston. the second time it happened it was only about 50km from the first time it was changed. it was noticed again because there was a coolant leak and the gasket needed to be changed. we cannot figure out the problem. does anyone have any ideas or have you seen this?

Did you check the ring end gap before assembly? Is your engine stock?