I had to replace the upper aluminum blade assembly not long after I bought the 788. Threads were stripped. Went to local repair facility and they sold me a new one. Not being used to the DeWalt, I asked why the difference on the assembly as the stripped one had something located in the left side hole across from the blade holder screw tightener. The person at the repair facility said it was a new type. Good thing I took the old one with me as I found out when I replaced the assembly with the new one that there was a set screw in the left side and would have lost it if he had thrown it away at the repair shop. I reset the set screw and the assembly works fine and I do not need any additional force on the blade holder screw and do not strip out the soft aluminum blade screw any more.