I have a loose lower head cable clamp in the Diablo 31 drive that must be reattached before heads can be installed

BASED ON THE EXPLODED PARTS LIST DIAGRAM, THE HEAD CLAMPS ARE TOO LOOSE

three clamps at upper left

Two of the clamps have a body with a tang that fits into a hole in the metal plate that is central in this diagram excerpt. If the bolts are loosened too far, the tang comes out of the hole and the clamp can spin around thus blocking the head from sliding into place. A third clamp must be oriented with its long axis vertically so that the sides grab on the two heads and lock them in place. When loosened, gravity causes it to turn 90 degrees so the long axis is parallel to the ground. 

The lower head clamp is not only too loose to have its tang in the hole, the bolt has disconnected entirely! You can't see the gap in the photo - very limited access for pictures or for working - but when I put an allen wrench on the bolt I can pull it away from the clamp entirely. 

I will have to do some microsurgery, getting a tool in to hold the clamp while I get the bolt inserted and the threads turning. I then have to tighten it up while maintaining its orientation until the tang enters the hold in the plate. It should only be loose one-half turn from a tight position. 

The upper head clamp is still threaded on the bolt, but its tang is out of the plate. This will be a somewhat easier surgery than the lower head clamp because all I need to do is hold orientation while I tighten it. Once it is in place, one-half turn loose should be enough to let the heads be installed.

When the upper and lower head clamps have their tangs in place and are appropriately loosened, I will try to install the heads while jockeying the third clamp vertical, as you see it in the picture above. I will then tighten it first, then loosen one-half turn. 

When the heads are installed, I can figure out what to use as the adjuster to align the heads. Diablo provides a tool (but I don't have one) that is threaded, to insert through the plate, with a conical head that will push against the side of a diagonal notch in the heads to make them move forward as the tool is screwed inward.