Volvo VN Operator's Manual page 255

246 OPERATION
The D-loop web guide is an area where almost constant movement of the safety belt
webbing occurs because of the relative movement between the seat and the cab. This
constant movement forms an area where wear will often occur. The webbing must be
closely examined to determine if there are any cuts, fraying or extreme wear in the
webbing. Cuts, fraying or excessive wear would indicate the need for replacement of
the safety belt system.
W8002478