1951 3100
Just re-did mine on a 51 216. Had some slop in the shaft. The flap was brazed to the shaft. Took a Dremel with a cut-off wheel and removed it. Then the shaft slid right out. Had way more wear on the shaft than the bushings. Made a new shaft out of 5/16" rod. I'm not sure how the original shaft attached to the counterweight, whether it was threaded or pressed or brazed, but I drilled out the old shaft, threaded it, and my new shaft screws into it. Manifold has what appears to be brass (?) bushings for the shaft. And they were remarkably in very good shape. Left them alone. Put the new shaft back through and mig welded the flap back. You don't have to run a bead all the way across the flap, just a spot on each side. But make sure everything is in sync though, so it doesn't operate in a half-closed or half open position.
When I got it all back together, with the spring installed, I took my heat gun and tried it. Works just like they intended for it to.
Mike
