I rebuilt my 03' 6.0 in july with new pistons, polished crank with std bearings, vinci cam, z06 valve springs and such. I noticed erratic oil pressure this week so I pulled the motor and the thrust bearing wore into the crank and small crap took out all the bearings and ruined the crank. I set the crank like my mitchell manual said and I thought it was all fine. The crank ran forward. Truck wasn't abused and towed very little. What cold the cause of this be since I don't want to do this again. Thinking of getting another motor because I don't want to pull this thing again. Thanks for any help.

 

Check the torque converter spacing.

 

I could spin the torque converter like a wheel before I put the bolts into the flywheel so that shouldn't be a problem. Taking it to the machine shop this morning to see what they say. Truck was a rollover and this is the third time the engine has been out so I'll probably pick up another engine from a local yard. First time it hydrolocked and bent a rod and broke a skirt. Dealer repaired it where I bought it from and then I fixed the rollover damage. It went 50 miles before it broke two pistons and rods were bent. I went through it with a fine comb and this happened. I didn't know if their was a different way to set the crank. Mitchell said to torque most of the bolts (can't remember which off the top of my head) and tap it back with a rubber mallet and then tap it forward and this sets the bearing. It's almost like I tapped it forward and that is where it chewed the crank. Oh well, might wait for a cheap crank and put it in my chevelle to replace the 5.3 I guess.

 

How much torque converter spacing do I need? The machine shop also mentioned that possibility. They said something pushing on the back of the crank is most likely the cause. Is this convertor only or can something be wrong with the trans? Could normal pressure on the trans shaft push the convertor into the crank or would it be more likely the converter? Thanks for any help.

 

What was your endplay when you bolted the engine to the tranny? That should be checked. Sounds like something after the roll over has that out of wack, the motor mounts may have moved or the tranny has come forward. Need to check that out.