Rocker problem

I had an oil leak and a nasty noise from the nearside rocker cover and when I removed it I found fragments of the right end rocker retaining clip and broken shims. The rocker was sliding along the shaft and missing the exhaust valve. I have purchased from ebay a rocker assembly but what could have caused the spring clip to be destroyed? There must have been a lateral force acting on the rocker. I have not yet removed the damaged rocker assembly for inspection, preferring to leave the head covered until ready to replace the rockers.

No sure on that one Joe, possibly not assemble right before you bought it ? Or just wear ??

Joe spotted these on eBay wondered if they might work with your headlights you were talking about ??
Look at this on eBay http://www.ebay.co.uk/itm/362077315060