....... Caniboomer doesnt the skidplate wear on case in area your magnet is attached to?
Actually, they do not rub at that location -- it's on the upslope slant of case, just in front of the flat bottom. You can add them to any machine without dropping the cradle, after swabbing the grease off the case with brake cleaner or alcohol. I use 3M VHB tape(thin gray version with red vinyl backer), and it holds them just fine. You can peel the magnets off cleanly when you want to remove/replace. There is also space under the motor, along the front part of the bottom. I have plucked them inside of rubber washers, and used them as forward cradle bumpers, at a point of 1/8" clearance. A 1/10" magnet inside an 1/8" washer is perfect, I'll find some pics later. Just note that some clearance differences do exist among the different types of cases, so each must be verified... but the upslant is always free and clear. Smaller magnets in multiples are also great.
For anybody that is waiting until the next motor drop to add magnets, they don't need to wait. There are plenty of external locations to stop migration of metal in the motor or frame. Combined with magnetic drain plugs, you can do it quite easy to any machine.