Next up is the mixer arm assembly discussed in parts that wear - mixers. Unhook the springs, and slide the arms out of the slots in the top plate. Take out a couple spring clips on the lift rod in the back, and the rod will slide out of the mixer latch coil plunger(s). Take out two screws that mount the pivot shaft in front, and the whole thing comes out, leaving this gaping hole.
On some machines with only the left side mixer latch coil, you can leave the lift rod in place. Just removing the two screws from the pivot shaft will let you and disengaging the arms from the top plate will let you tip/slide the assembly out of the mixer latch coil plunger.
Clean the gunk of the metal plate, then clean rest of the pieces. I usually take off all the spring clips and take everything apart so I can clean the pivot shaft and get the crud out of the joint on the latch arms themselves.
Here is the arm assembly with the spring clips removed. The clips keep the pieces spaced along the shaft correctly. Remove the spring clips with a pair of needlenose pliers. Try to avoid letting them fly...I slipped on one and it shot over my shoulder and landed on top of the machine head ... three feet back and three feet up!. Fortunately, you can get the clips at the hardware store when you lose one or two.
Now take the pieces off the shaft and fix them as described in the "parts that wear" section.
You have all the arms fixed up and cleaned off, so now you just reassemble and mount it back on. Right about this time you'll notice that on this game the shaft is asymmetrical...the length from the end of the shaft to the first slot for a spring clip is different on the two ends of the shaft. Well, it only really lines up one way, and to the best of my recollection (which I wouldn't count on), the longer end goes on the left.
Here the pivot shaft is screwed back on (notice screw on the side of the plate below/right of the mixer latch coil). The lift rod and the mixer latch coil plungers aren't on yet, and you need to reattach the springs that are dangling up at the top.
The lift rod is reinserted, and the mixer latch coil plungers are grabbing it. The cup in the plungers are facing the back.
The springs are back on, and most importantly, the arms work right. See how arms two and three are down. If you push against the roller, the arm will release and get pulled up like the others. Well, except the arm on the far right, it actually works differently. It's job is to let that mixer rotor index only one position per machine cycle. If you happen to have a diagram of this mixer, and you know what position it is in, you would know what the next coin/credit played would partially allow/disallow!