Hey mdmessier
the auto shutdown actually comes from the auto-shut off brush's..once they wear down they have a push pin that comes out and push's it away from the armature..so as long as you have an extra set of brush's..[and maybe a switch] you should be ok..any other service or repair is best for a service center as it could get involved..
so how's the weather there?..I just had to put on an extra pair of socks..brrrr..
hope this helps..
Craig