Ok y'all this has got me stumped here. So I have a low mileage LY6 stock bottom end that I am putting a new valve train in because of a cam failure. I took the motor completely apart to clean it. So I put in the crank today and put in the same bearing that it came with and it doesn't spin. And I mean it is locked down! Won't even budge with wrench. I took the caps off one by one and it still wouldn't spin with just one cap.

How can a freely spinning rotating assembly come out and I reassemble it EXACTLY the way it was and now it's locked up? Same bearings, caps oriented the right way, torque procedure followed. No I didn't check clearances....but being as they are the factory bearings that have been fine this whole time I didn't see the need to. I'm going to get my micrometer this weekend and measure. I just don't get it. Any advice?

 

I'd take it all the main caps off and check each to make sure shells are seated properly with no crap under them. If all good, lift the crank out and check the other shells. Double check to make sure caps are sequenced properly. I can't imagine what mic'ing things would tell you, as was said, it had clearance before.
That's all I got.
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Could be a bunch of things; did you set the thrust? How did you clean everything before putting it together?

 

What exactly is assembled at this point? Entire rotating assembly? Is the camshaft in the block? Heads on it? Timing chain? Oil pump?

 

Hi, did you mark the caps first before removal ?

What I state is the front/rear facing direction.

Did you check the thrust alignment, center main, block/cap ?

Lance

 

Ok y'all I figured it out. Stupid mistake on my part. I have another motor disassembled and I mistakenly used the main caps and bearings off that motor! Put the other set in and everything is fine now!