I find three different Lippert 1621 pin boxes. They are rated at 15.5k, 18k and 21k. Shipping weights are 100, 105 and 115 lbs. Obviously heavier due to more and/or thicker steel
From what I can figure out the 1621 is 15.5k and the HD comes in either 18k or 21k.
So my question for the OP is- if your HD version of the 1621 pin box has issues, it looks like the standard 1621 which is very common on fivers would have major failures with the Andersen hitch. Yours is the first issue that I have heard of and you have the HD version.
So this makes me wonder if there is some other explanation?
