Jack Klute:
I have purchased a new control yoke for my sierra. It looks like
there are only two (2) pins holding my control yoke to the shaft. Does
anyone know if there is a special procedure to remove and replace
these pins and are the pins reusable.
Search strings: yoke shaft, yoke stub, taper pins, tapered reamer, tapered shaft, yoke removal, universal joint.
Bob Steward, A&P-IA:
They are AN 386 Taper Pins, and work by having the hole reamed with a
special tapered reamer (Brown & Sharp taper), and then the pin is pressed
into the hole and the washer and nut started on the threaded end to secure
the pin.
Yes the pins are reusable. The procedure to remove them is to take the nut
and washer off and then press the pin such that it backs out of the
taper. A C-clamp with a spacer over the unthreaded end of the pin work
nicely. The spacer can be put over the threaded end when it comes time to
re-install the pin.
As mentioned by others, the disconnection of the primary flight controls
must be supervised by an A&P and a proper return to service entry in the
logs made upon completion.
Here are some links that may give a better understanding:
http://www.aircraft-tool.com/shop/detail.aspx?PRODUCT_ID=1BS&ReturnPage=/shop/search_result.aspx?PageNo=1
http://www.aircraftspruce.com/catalog/hapages/an975taperpinwshr.php
http://www.aircraftspruce.com/catalog/hapages/an386taperpin.php
Editor:
Bob’s response addresses the forward end of the yoke shaft, where it is pinned to the universal coupling. That is a natural response, since yokes are seldom separated from their shafts.
However, if you are talking about separating the yoke itself from its shaft, those are structural rivets. They must be carefully drilled out, and just as carefully replaced; the holes must not be elongated. They are not reusable. Whether you have the large-necked shaft, or the one that is tapered on both ends, there is a mating stub that is structurally bonded into the yoke itself. That is the part that is riveted into the yoke shaft.