2002 Chevy Express 3500 5.7L

[Reina]

bought a van that would't start I was told that the van needed a flywheel. Replaced flywheel and when attempted to start it it made an awful clanking sound I thought it was going to brake to pieces. In fact the starter was not catching the teeth on the flywheel just skidding so I replaced it. still having the same problem it goes to start ignition and loud clanking continues.

[ProTech]

You may have damaged the new flywheel with the old starter when it was failing. You'd really need to remove the inspection cover and actually watch what's going on as someone cranks the van over. Could be worse than you expect, too, and have some internal damage.