Anybody got an exploded diagram of the proportioning valve or a good explanation of how it goes together, my old one cracked and the bone yard one was really gummed up, so like an idiot I took it apart, then got called away and forgot exactly how it goes back together (what a dumb arse).

Is there not enough information for you in the FSM?

The FSM and other on-line resources only show the exterior or the location of the valve, I need to know how the guts go back in the body, spring, washers etc. It has 2 22mm bolts (top and bottom) which are easy, they can only go one way, but the plunger springs and washers are another story.

Take the cracked one apart.

Oops, brain fart, found the diagram sorry.

Here is a pressure differential switch to get you in the zone: