So, i recently picked up an old 2001 ram 1500 3.9l.(103,000 miles) It needed some work. From the start, i knew it had transmission issues. Reverse did not work. It had a bad coolent leak. So i replaced the oil pan gasket, the timing cover gasket, and the water pump. Got it back together, and it fired up great! But was knocking bad. Thought it was the Engine at first, and that i had perhaps put to much oil in. So i drained half a qt. The problom continued. So, i checked to see if the knock continued if i put it in diffrent gears. And i realized, that in reverse, (the one gear that dosent work)the knock stops! So now im wondering if it is the trans?.. however, to my knowledge, i did not mess with anything trans related. And it did not knock prior to working on it. I am no Mechanic by any means. But im 90% sure i put it all back together correctly. The knock it loud, and goes faster with rpm. I let it warm up, and reved it a few good times(2000-4000rpm). Now, the knock also happens in reverse, but not as loud as the other gears. Any ideas would be wonderful! Thank you!

 

Did you check the converter bolts? Did you bend the cover taking the pan off?