Well, I am hoping that sooner than later I can post in the forum, but at this time I can only post to introductions.
Got an HT20 with 54" mower (18071). Had an idler pulley go out and found I have a mess with joint where of the pulley supporting the dual idler. It appears I do not have original hardware (spacers and bushings) which is cocking the assembly so my new idler is sure to fail again unless I find some corrective parts. Problem is I am not sure what is original and what was put together to get it to kind of work? I sent some emails based on the parts supplier thread but I can't get dimensions and information to verify what parts I need to order and what I have....
171-4299 bushing (nylon?)
I believe the idler arms (top and bottom) are original but not completely sure...