I just rebuilt my engine, and put a new flexplate on my engine. I also put in a rebuilt tranny, a new TC and a doubler. When I start the engine it knocks really bad. If I put it in drive it goes away. I am thinking that it might be something in the flexplate area. It could be hitting the bottom portion of the bellhousing, would that cause it to knock? It goes away when I get on the brakes and put it in drive. But if I let off the brakes and move it, it gets bad. I started the engine w/ no tranny hooked up to it a while ago and it sounded fine. I istalled the flexplate I believe with the correct side against the engine, but it could be the wrong way. The counter weight is on the engine side of it, on the old flexplate I believe the weight was on the tranny side. Any ideas? Thanks!