Steve777 wrote:
Thanks Mtnman.
Good thought, I double checked and I don't think this is the problem on this engine. If I am following you right, that would have the sprockets flipped front-back, and the bolt and washer would end up in the recess that is the press fit for the end of the shaft. That's not the case on this engine. Cam bolts are on the flat, and gears are not far forward, as I think your way would put them. And the belt is sitting on the sprockets normally.
What I am seeing is wear on the back/rear cover, the alum casting that bolts to the engine block and head. It's caused by the sprockets/cam shafts moving back into the engine and rubbing on that rear cam cover. Could also be the rear cover getting loose and moving forward causing it, but that seems highly unlikely.
I have not yet tried the tapping test to see if there is excessive motion/play in the cams, because I have a bit of concern that the rockers could be pushed sideways from such a test. Anyone have any first hand experience of how much pressure is between the rockers and cam lobes when the engine is off and the lifters have drained down? Think it is safe to try tapping the cam shaft in to see if it has excessive play there?
You're right, backwards sprocket would be more inclined to hit the front cover, I misread which cover you mentioned. Hmm, 1/8" of movement on the cams would be a lot. I think your cover is loose or something is behind it, or perhaps a PO bent it?
Unless the front seal is leaking, I wouldnt mess with the cams, as you may start a leak.