Thu Nov 26, 2020 4:40 pm by cornbinder89
the 1/4 or so round shaft with the slit cut in it runs right through the manifold and out the other side. Inside it has a flapper valve that either direct exhaust gasses up against the bottom of the intake, or diverts the same away.
That shaft is supposed to move, often it get stuck and needs to be free'd up by heating and working it carefully. Once it is free it can be lubed with graphite or a spray made for it.
The bi-metallic spring turns the shaft when cold to direct the gasses toward the intake, and when warm the spring turns the shaft so the flapper directs the gases away from the intake. The little "peg" is there to hold one end of the spring, and the other end passes through the slot on the shaft as seen in the pictures on the other page of this thread.
You may have to remove and separate the manifolds to free it up if badly stuck.