I had finished rebuilding my motor a few weeks back and has checked endplay and it was in spec so I thought that was all good. a few days ago I went to go put my oil pump and chain on and realized I had forgot to put the thrust washer on the counterweight side of the stack on. When I put the stack back together I had zero endplay. the plates have been lapped but it was their first time going through the process and I had a “K” spacer in there but I would think even if I went to a thicker spacer I should still have a slight bit of endplay with the current spacer. With the crank bolt slightly loose I get end play and with the thrust washer missing I get endplay but when the washer is in there, zero endplay. Any ideas what’s going on?

 

Before you get ahead of yourself, does the engine turn over freely with the timing hub, thrust bearings, front counterweight, etc. removed?