I rebuilt my 5.3 ls engine over the winter and then when it was finished.I drove it around for about a week, the oil pressure started dropping slowly.Then one day while driving oil pressure went to 0 ,so I decided to pull the front of the motor and check out the pump.when i did i noticed that the cam shaft thrust plate was cracked when I pulled the timing chain off i found that the gear wore a groove into the thrust plate and cracked it.what would cause it to do that? help

 

Not a rebuilder, but experience in these things. If he the thrust plate is wiped, you do not have enough axial gap on the cam shaft. Not exacting what thrust you should have, my guess is .015 would put you in the ball park. You should consult the mechanical spec's, also is the oil bearing clear?