I have a brand new BX2680 with under 30 hours use. I removed my 60” mower to rotor till my garden, raised the lift arms and locked them in place. Knob marked at “Top”. The right lift arm fell and got jammed under the tractor bending it and breaking the weld on the bracket holding up the front of the lift arm. The left side remained in place. I was looking on the internet and found others with the same experience.