A friend of mine has a 99 suburban 4x4 5.7 350 Auto trans. 200k original trans 4l60e Motor was rebuilt about 60k ago. And is making a strange clunking noise when started up at running idle, almost sounds like a rod knock. Oil pressure is good says it sounds like its from the back of the motor like the transmission. A friend of his told him it is the transfer case possibly a loose drive chain. Doesn't the drive chain only move when you are in gear and moving? I'm thinking its either a loose torque converter to flywheel bolts/broke flywheel, or bad input shaft on the trans or bad torque converter. Whats everyone's thoughts? He says the clunk disappears when in drive and moving. Its kinda hard to diagnose by not seeing it. any thoughts and ideas is great help! thanks,
