[Richard Coutts-Smith]

Have been told in the past that these covers act as sacraficial anodes, but after talking with Australias part time Champ Diff Guru, and full time metallurgist, I now discount this theory, and happily replace these plates with Brass or Stainless Steel.
Certainly a good argument for using good an anti corrosion inhibitor .
Of course it is easy to say check the plates, but the rearward ones are a pain to get at (in the Humber), feels like I have pulled half the truck apart to get to it.
With plates of it is also a good oppourtunity to stick the garden hose in and flush some crap out.
Rich.