ive seen alot of threads where this has happened (gears getting chewed up), but not many explain as to why.
it was freshened up 2.5 CB that i dis-assembled and re-assembled. i plastigauged it when it came apart and when going back together, everthing checked out great.
i had some fuel diluted oil in it for about 50 miles or so, as i had forgotten about the no spark issue i had back in october. i changed it and oil press was still pretty good about 50+ cold and 10-15 psi hot idle, and pretty much spot on with the 10psi per 1000rpm. i did have a slight oil psi drop over the next 2-300 miles, but still within spec and no bottom end noise, jusy slight top end noise.
i had also been fighting a upper rpm miss that i just couldnt get a grip on. while trying to find the miss, i did notice a bit too much play in the rotor button and the shutter wheel was tight. sine the tracks are getting ready to open i figured it be a good idea to drop the pan and have a look see. now, the engine still ran fine, no knocks, nothing out of the ordinary.
man, if i would have waited any longer the motor would be junk. all 4 rod bearings were wasted and the #3 main was toast. The no.3 main cap was black, is it no longer any good? or just a line bore on the block?
when the pump came down it was obvious, the hourglass shape and chewed up gears says it all.
But what is usally the cause of this?
I guess thats what i get for re-using the old pump.
Here are some carnage picts, enjoy.