Mower deck skirts
 

Mowed yesterday and checked blades after I finished , noticed a metal plate sticking in under the deck , upon closer inspection I realised it was a skirt on the deck
It had come adrift at one end as the retaining screw head had completely worn away
The screw was a hex head 1/4-20x.5 and used in a number of areas on my Cub GT2550
There are a couple of these skirts on the deck and my presumption is they are a sacrificial part instead of wearing away the deck edge but I was surprised that a hex head had been used instead of a dome type head
Anyway the point of this is a suggestion that you check your deck to ensure all retainers are in good condition
Oz