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Has anyone ever had the compression donut cap casting (GM-6) break?
These are the castings that go on the top and bottom of the GM-33A
compression donuts on the main gear and are held together by a bolt and
nut.

Preflighting on Saturday, I discovered the lower GM6 on my right main
had fractured just below the nut which holds the compression donut
assembly together and was turned 90 degrees, with the compression donut
sitting on the edge.  The bolt inside the donut remained attached to the
broken piece of the GM6.

Today I took it apart and found that the bottom of the donut was dinged
pretty well from contact with the edge of the broken GM6.  I believe I
must have made at least one landing in this condition.  With the weight
off the wheels, the right main falls straight down, so I can only
conclude that wind pressure held the gear against the bottom of the
donut.  Also it could not retract fully because the wheel would not
align with the well, so I assume it just went up until the tire
contacted the bottom of the wing.   No damage to the bottom of the
wing.   This seems to be a good argument for having "gear up"
microswitches, which I do not have.

If the donut assembly, which was just hanging on the upper pivot, had
swung back a couple of inches there would have been no support for the
wheel and would certainly resulted in an exciting landing.

About 2 weeks ago I replaced the compression donuts with new ones.  The
new ones required slightly more compression force.  I wonder if this is
a coincidence?

Today I called Lancair and was told that they had not seen this problem
before, and they asked me to send the broken part in for examination.
They also volunteered to send a new GM6 at no charge, and this is for a
kit that was delivered in 1986!  Lancair has always given me first-class
treatment, even though I am not the builder.

(Lucky) Bob Belshe     N19BJ    Lancair 235/320