DDoyle

Sounds like the winch and shear pins are working properly in the first instance. The winch is rated at 10,000 lbs. The M35A2 weighs more than that - without the coefficient of friction that would come with the "brakes locked" scenario.

I've gone through perhaps a half-dozen shear pins - all surplus, in various situations. The biggest strain, which did not shear the pin, was winching a tank from a ditich - the transmission housing flexed enough that gear oil leaked between it and the PTO (fortunately, it didn't break). I bought a truck once that had the shear pin replaced with a bolt - and it had a burst winch housing...and I've seen several burst transmission housings.

Best wishes,
David Doyle