Mysterious "clunk"

[mattswan267]

I just put a new engine in my 2002 Ranger and got it running the other day. It was running nice and smooth. This morning I started it again and it sounded the same other than I heard a fast pace clunk from underneath the truck. Sounds like its coming from the tranny. I don't think its anything with the engine because it was just rebuilt. I tested the oil pump and its good. The engine oil is good and had good oil pressure.

Any ideas what this could be?

 

[stiluv]

did you damage the shield that is sandwiched between the trans and engine? that could be hitting the flywheel.