If you have welding capability, or a shop nearby, one can mount almost any gear box on any mower, just drill and plasma (or torch) cut hole for new box on a 3/16 or 1/4 sheet of steel and weld that to the old deck. Stronger than new with minimal fabrication.
Yes, BUT lookout for mounting depth and assumption of shaft length down to the stump jumper. Doing as bumperm says you'll end up having to replace both the gearbox and the stump jumper unless very selective. The mounting bolt pattern distance down to the stump jumper must match and of course the gearbox output shaft and stump jumper have to mate well. (duh,... obviously.) In fact I supplied a used gearbox to a friend who mounted it on his old bushhog and tried exactly what you describe. The blade carrier would not clear the body of the bush hog. Had to start over.
BY THE WAY This being a very OLD thread, I just studied what I had said on it several years back & others comments. See post #129. This does NOT help/fix your dilemma and expense.
I do think I have a better idea now of the reason for the widely reported MX6 problems. I am amazed that I see no other post in all that long sordid history that mentions this. (I could have missed it during review...)
I think that the MX6 problem was due to the design combined with users not rechecking tightness of the bolt holding on the stump jumper. The design is that one center bolt holds the whole thing on -- WITH NO KEEPER AND NO COTTER KEY AND NO CROWN NUT. That bolt is supposed to be torqued as i recall to 450ft-lbs. How many users will check that once in a while ? ALMOST NONE. Unless the user gets out his larger high rating air wrench he has no way to get 450 ft-lbs on that bolt. Those without such an air wrench will probably not find a long enough cheater bar. End result: The stump jumper and blades are going to fly off at some point (!) I used mine back in the 2001-2011 period and had around 300-400hrs on it. The stump jumper never flew off until I had used it for several years. Came off several times before I wised up, read the torque specs, and finally used a long enough cheater bar ! (And that is enough to break most 1/2" socket sets ...go find your 3/4". )
Bottom line: I am convinced that the bad rap on the MX6 was because:
-- the unsecured bolt that holds on the stump jumper came loose (eventually, just a matter of time) on a large number of machines
-- in some cases (like mine) I was lucky enough that it never broke the shaft
-- in many cases (reported on this thread and others) when the stump jumper came loose and went flying the weight of it hit the side of the hog body or something else and hit the output shaft with a huge shock of sideways force -- enough to crack or even break off the shaft.
That's how I think so many of them got broken. Pee poor design without any cotter key or way to prevent loosening of the center bolt. Unrealistic dependency on users to periodically check tightness, especially to a torque figure they cannot achieve with their socket set. That's my theory.
