I have bleck and decker grass hog auto feed and it does not work

Which part of the Grass Hog did you take apart? If you mean the spool head, that is easy to reassemble. The actual spool (the round part with the line coming out) goes into the cavity on the bottom of the trimmer, with the line poking out of the hole in the side several inches (not enough to hit the plastic guard). Then the cover (orange with the spring on it) fits on top of the spool so that the spring pushes on the spool and the two tabs on the side snap into the holes in the trimmer.

Unless you took another part off, that should be all you need to do to reassemble the Grass Hog. Turn it right-side up and turn it on to make sure everything works.

To lengthen the string:

- Turn the Grass Hog upside down
- Push in on the two release buttons on either side of the spool (they're orange)
- Pull the spool head off and spin it to release more string while you pull the string with your hand (make sure it is still fed out through the hole in the base)
- Pop the spool head back into place

Test the Grass Hog to make sure the string is not too long. If it is you'll hear it cracking against the plastic guard on the base.

Is the string spool seated on the rachet correctly? If so and all is well, it is worth noting that these trimmers auto feed fuunction is problematic at best, requiring manually unwinding some line every few minutes as the unit gets older.

For Black and Deckers: Remove cup from bottom of unit by depressing 2 detent tabs and pulling away from unit. Replace empty spool with new full one or wind on aftermarket string. Wind in direction of arrow on spool. Make sure spool is seated on rachet firmly.

wind in direction of arrow on spool. Use 2 separate pieces. 1 at top and 1 at bottom. Feed 1 through each opening in hub when done.

The spool should pull straight off

http://www.dewaltservicenet.com/documents/English/Instruction%20Manual/244137-01,GH600.pdf

if your refering to the batt handle then its a obsolete item with no replacement part number. your part # is 243215-00 and your best bet is to sell it or put lots of ducktape or epoxy or keep checking ebay

It's cheapest to buy a new one. I had that problem last year.

You may need to purchase a new spool housing, which may not be too hard to do, if you have one of the name brand trimmers. This replaces the whole mechanism that holds the line, the retaining ring, etc.