[R-390] Info from HSN Issue 37 on repairing a bent PTO shaft

[Les Locklear]

STRAIGHTENING A BENT R-390A KCS CHANGE SHAFT [Shawn Merrigan] An R-390A purchased
"as is" from Fair Radio had a bent KCS (vfo) change shaft which wobbled visibly when rotated. This
caused binding at the bushing in the gear plate and at the front panel bushing. The result was a hard to turn
KCS change control. I could have simply loosened the front panel bushing lock nut slightly, allowing the
shaft and bushing to float, but I decided to do the right thing and replace the shaft. This is a fairly
straightforward job, but there are a couple of things to watch, and keeping them in mind will help:
1. A taper pin indexes the dial lock hub and gear to the KCS change shaft. This pin has to come out
to remove the shaft. Drive the pin out from the narrow side! This is a small taper pin.
2. A larger taper pin holds the ten-turn stop assembly on the KCS change shaft. This pin must also
be driven out from the narrow side. Look for the smaller of the two holes in the ten-turn stop end
block (looks like a big thick washer) and drive the pin out from that side.
3. When driving out the pins, particularly the larger one, counterbalance  the shaft with a large mass
so you will not bend it. Use WD-40 to loosen the pin and tap gently.
In fact, I wound up straightening out the old shaft using machinist's V -blocks and a brass drift. I then
polished the shaft to remove any burrs and blew out the taper pin holes with WD-40 to prevent binding'
The run out of the straightened shaft was very small and, after re-assembly, there was no binding evident
and the shaft turned smoothly.

Les Locklear