I bought a 77 Archer in July and had exactly the same problem.
Mine would only power trim in one direction and the trim wheel was stiff to
turn by hand..
Most likely it just needs a fine adjustment of the castle nut on top of the
friction drive clutch.
I worked the trim switch on the yoke while my A&P did small adjustments, one
flat of the nut at a time, until it was working great in both directions and
silky smooth when trimmed by hand. Put the cotter pin back in and job was
done in about 30 minutes.
Later I did clean and grease the jack screw at the tail because it was
pretty dry.
--
Roy
N5804F - PA28-181

"Jonathan Goodish" wrote in message
...
I have a 1977 Archer II with factory-installed electric pitch trim. The
trim servo motor works in both directions, but it doesn't work well for
moving the cables. When the ambient temperature is warm, the electric
trim works acceptably but occasionally seems to "slip," and when it's
cold, I can forget about it. The manual trim wheel seems to have smooth
movement regardless of temperature, though it is a bit stiff in
extremely cold temperatures. When I run the electric trim, even in warm
temperatures, I can literally place my finger on the trim wheel and get
it to slip.

I do have the Piper maintenance manuals for the airplane, but it appears
that the maintenance manual for the electric trim system is not included
for the Archer II. I assume that either the servo clutch is bad or the
jack screw needs to be disassembled, cleaned, and reassembled due to too
much resistance (though the manual trim wheel is not hard to move).

Does anyone have a suggestion, or know where I can locate the
maintenance manual?



Thanks,
JKG