I've been pulling stumps for years with the 46 backhoe. I'm so bad that I hook the stump with the hoe and drive forward!
The trick to pulling stumps is to work about two feet out from the stump. The roots are weaker the further you go out and it makes the job easier.
In any case I've never bent anything excepting the teeth! I have some hard face wire for my MIG and someday I'll hard face them when they get bad enough. Although they are pretty bent now!
One more thing, I use a 13" bucket for the hard pan in the Catskills. This is a 'two rocks for every dirt' place as Nancy likes to say!
Being an engineer my guess is that the arm was bent slightly when you got it or the sleeve was worn and out of line, the force of working did it in. Think about bending a steel bar. If it is 100% true then it's just about impossible but put a little bend in it and you multiply the chances of it bending 10 fold.
Before you rent anything again check for play in the BH and check the hours on the machine. Also check for worn pins. If a pin is worn it's possible it is worn on an angle and the force on the ram is to one side which will bend it under load. The Deere BHs are pretty rugged and this shouldn't happen with a properly maintained and lubed machine. Check the other parts on the one you just bent, they will give you the general condition of the BH.
Rob
