On Wed, 12 Aug 2009 19:01:35 -0500, dkh wrote:

about 80% of the time when switched to high speed (in drill,drive or
hammer action mod) the chuck spins but there is ZERO torque (you can
literally stop it with your hand). Fiddle with the speed switch for a
while and it works ok again...

Is that "speed switch" an electrical one or just attached to a gear
box? Whe you say "the chuck spins" do you mean you can rotate it
freely by hand or does it run up to normal speed by power but takes
no effort to stop. If you let the chuck go and retain power on does
it run back up or stay stopped? Are there any noises other than motor
whine?

Personally I'd be looking for a mechanical problem, clutch or gears
not engaging properly.

--
Cheers
Dave.