LAC: Jetta weight?

[George Selby]

I don't have a VW list to ask, so I'll throw this one to you guys (and gals):

I'm replacing the halfshaft on my 90 VW Jetta.  Immediately below the inner 
CV joint I'm removing is a large block of metal.  I took it off, and that's 
exactly what it is - a approx. 5 lb hunk of metal attached to the bottom of 
my car.  It is shaped like a brick, and has two bolt holes, and is attached 
with factory type bolts.  Any guesses to it's purpose?

George Selby