goldcoastmoz said..
There was a thread on this a while ago, I had the same and the dealers had no issues replacing the boom.
That looks like an older style head? Same as you, I got mine replaced (happened within 3 months), but after the next one did it - and my longer boom went the same way I decided not to get them replaced.
On the flip-side, it's mostly cosmetic due to the plastic casing being too rigid and not allowing any flex - the plastic cracks whilst the rest of the boom performs as it should. It also allows you to keep an eye on the alum corrosion under it.