[MichaelBick]

The three teams that I know of that used 3 motor gearboxes were 33 2012, 973 2011, and 254 2012(I'm sure there are a lot more, these are just the ones I know of off the top of my head).

1) I know 973 ran into problems with their 3rd motor because it was a 775(case short problem). I've heard that if they were to do it again they would use a 550 instead. Not quite sure if 254 or 33 ran into problems. I know 254 and 973 ran theirs off their WCD shifting gearbox. IIRC 33 ran theirs off an AM shifter. One of the things that I noticed was that 254 was able to gear higher this year because they used a 3rd motor. According to their website, they geared over 20 FPS with a full weight robot, something that would have been unable to do otherwise(very slow acceleration).

2)Never heard of burning out motors. I'm pretty sure 254 and 33 ran a 550. I know 973 used a 775 later and regretted it after due to the case short problem.

3) 254 ran their normal wheels. Not sure about 33. 973 ran wider (2" wheels), though they ran these same wheels once they took the extra motor off. I know it allowed them to push most people, even with only 4 motors(they pushed 469). I don't know if they used 2" wide wheels specifically because they were running 3 motors per gearbox.

That's a brief overview of what I know about 3 motor gearboxes. I've never actually made/run a 3 motor gearbox, so take this all with a grain of salt.