[Patrick Wang]

I don't know exactly how these year's drill motors will behave, but it seems to me that you may have issues other than simply pulling too much current.

Make sure all your electrical connections are sound. A loose wire will cause you to pull too many amps and trip your breaker.

Also check to see if your drive train is freely running (assuming you took out the backdrive pins) there could be a bent axle or the like that is introducing a lot of friction to your system.

That motor should not pull more than 30 amps driving around freely.