I'd appreciate if you could elaborate.
Certainly! There is an aluminum block that is about 1.5 inches square and 1/2" thick that pivots to block the arm in the up position, or allow it to drop down into the motoring position. The pivot shaft for this block is soft, 1/4" alminum. It bends easily and once it bends, you might not be able to pivot the block.
You have to extract a small "allen" set screw from the block to get this aluminum shaft out. Since the allen screw is high carbon steel and it is embedded into aluminum, there is a probable chance that you will never get it out if you don't do it when it is new.
This soft aluminum part should be replaced with a stainless steel bolt that is 1/4" in diameter and the appropriate length. (about 4" ?)
GARY