How do I fix a grandfather clock which has been wound too tight?

Wound too tightly= no such thing-no quick fix.
Check the movement for obvious bstructions,
rodents' nests,toys and other non mechanical additions.
Education is a condensed form of experience,so:-
Borrow a book from your local library on clock repair,view some of the clock repair guides on the internet and then check for wear(pivot holes etc) or damaged parts.
Repairing wear(re bushing pivot holes) is easier than cutting new wheels (gears) and can be done by hand with a few simple tools.
Good luck,and don't let your husband drink sherry it can lead to stupid grandsons apparently.

Ferg.
April 2010

My Grandfather likes to wind down with a small sherry and a Frank Sinatra record.

Grandson
March 2010