Few days ago I hopped in my truck and drove to the store. I noticed after about 15 minutes of driving, I was hearing a ticking/knocking sound at the stop lights. Oil pressure was good, about 30 psi at idle and 60 while driving.
Got home, snooped around and the noise is strong at the flexplate/converter area. I took an automotive sound tester and checked around the oil pan to make sure it wasn't a crank or rod knock. It is indeed coming from the transmission area.
The sound is noticeable at idle, park or neutral, and it seems to go away as the RPM's go up. I checked obvious things like fluid levels and all that is good. I took a flashlight and looked around the flywheel and saw no noticeable cracks. I checked the 3 converter-flywheel bolts and those were tight.
I took a floor jack and put a slight amount of pressure on the center of the 700r4 pan. The sound immediately went away. Release the pressure and the sound returns.
I was thinking a few possibilities here. Maybe you guys can give me some insight. I was thinking a cracked flexplate. I was also thinking possibly the filter in the 700r4 collapsed and is hitting the pan... making the sound travel? When I put pressure on the area, the noise stops. Also, possibly the transmission mount? I replaced this mount 2 years ago but it's already deteriorated with oil.
I did plan on having this 700r4 rebuilt this winter anyway. For $10, I think I may try a new transmission mount. If not, I will wait when the transmission is rebuilt. Hopefully at that time, the cause of the noise will be obvious.