Camshaft pulley defect - EW7J4

[406ST]

Hello,

My first topic on this fine 406 forum.

I have a 2002 1.8 Peugeot.
I recently heard some noise from the engine compartment ant I located the sound to the timing belt!
Opened the upper timing belt cover and I noticed, that the harmonic balancer on the exhaust camshaft pulley was loose...

Found a new on Ebay: http://www.ebay.co.uk/itm/Camshaft-Pull ... 2275444531 but my question is:
The engine has covered 305.000 km and still runs fine. I never drive more than around 3000 rpm.
1. Is the harmonic balancer strictly necessary og can I drive without?
2. Is it possible to change the pulley by locking the inlet camshaft and fixing the timing belt and only tetaching the upper timing belt cover?

Best regards

Claus from Denmark

[406ST]

No experience?

Regards

Claus