Did you know about this site? ereplacementparts.com
I needed some parts for this pos Black and Decker electric weed eater and they seem to have cheaper parts then blackanddecker.com? 🙂 They actually win because of their economical shipping their price of the item was actually more though.

This is the unit I have:  BLACK+DECKER LST540 Brushless String Trimmer, 40-volt

I also owned this version:  Black & Decker LST136 13-Inch 36-Volt Lithium Ion Cordless High Performance String Trimmer