To those anxiously awaiting their RD-1C gear
drives, here is the good news / bad news story.
Just got the results on some troubling spline
fit anomalies with the RD-1C propeller shaft. The problem was
that a Genuine Ford planet carrier would fit nicely on the shaft but an
aftermarket part simply would not slide onto the shaft. To the naked eye
they looked the same and the major & minor diameters measured
identical.
At first I though the aftermarket part was just
made wrong and I would simply have to use only Ford parts. On close
inspection (backlit spline fit with a 10x eye loop), it looked like the spline
teeth only had a point contact at the tips of the planet carrier spline teeth
(this was on the Ford spline). This would result in very fast spline
wear, increased lash and possible failure. The attached picture tells
the story.
After getting the data from Ford on the planet
carrier spline it was clear that the pressure angle on the prop shaft spline
did not match the carrier. Result: $7200.00 in scraped
shafts. The only good news is that new shafts are in
process. Still not sure who absorbs the cost but either way,
someone gets the shaft. (please forgive tasteless pun) Actually, the
supplier has agreed that if the problem turns out to be what I just described,
they will accept responsibility.
Isn't product development fun? I'll post an
update to shipping schedule when we have it nailed down.