the only weak spot that I have heard of is the exhaust pipes. If an RPG hits the end of the pipe and slides up it before it blows, you can destroy the engine. The ammo has blow out plates so it the ammo burns, the gas is not exhausted into the turret, therefore the crew is uninjured. This happened a few times, In Iraq this time, the worst trouble has been tanks sliding into canals and sinking. the only tank lost in the first gulf war was the crew's fault. The m-1 pulled up besides a burning Iraqi tank and the thing blew up setting our tank on fire. dumb.