Ok. Sorry for your loss. Send it back to castle. they'll hook you up. Dunno if it goes to warranty though.. Next time use much smaller pinion, start like 10T. Did you check temps from the motor and batterys?

it happened on the third run, I checked on the first two runs. The third one it never moved.

I guess you had quite some cogging, next time don't run if it coggs. The motor tries to take too much from the system and the esc won't handle it..

Well I got an email from castle today. It looks like they are sending me a new unit to replace my cooked one. Now I need to know what size gear to use on the motor to keep this from happening again. My LHS has the hardened steel starting with 11 tooth. I would like to top out around 40-45 or so if possible. I am only running a 4s lipo right now but I would like to upgrade to two 3s in series in the very near future.

So your setup is something like this now?

Differential Ratio: 2.888888888888889
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 11
Total Voltage: 14.8
Motor KV: 2200
Tire Diameter (inches): 7.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 4.18 : 1
Total Ratio: 12.08081 : 1
Tire Circumference (inches): 23.56 inches (598.47 mm)
Total Motor Speed: 32560 RPM
Vehicle Speed: 60.14 mph (96.6 km/h)
Effective KV Value: 2200

That is too much for heavy truck imo, sucks a lot of current with 4s. Dunno really what you should do, since you have bought the 2200kv motor. Your options would be using smaller kv motor, get bigger spur or smaller tires. With pinion you really can't go any smaller 11t is quite small already, maybe you can find something like 9t hardened?
I would try first smaller tires with 9t pinion. Just play with Briang's calculator and aim the speed around 40-45mph. And test it out, watch temps very often. Hope this helps..

I would ditch the 7"+ tires and go with a truggy style 5"+ which will bring this set up to a more friendly 43mph+.

Any idea what the matrix tr tire size is. I'm having a hard time finding info on them. I'm not quite sure about using a tire that is so much smaller, this is a really big truck and I don't think it will handle well if the tires are too small. I found the 66t spur on ebay, for 25 shipped so I ordered that and may just go back to the drawing board on my mount that I made. I may be able to work with it and make it a little more adjustable. I'm also wondering if I run the center diff gears instead of the locker if that would take a little stress off the motor.