Washing machine?

We had a coin drop down the detergent dispenser of our Fisher & Paykel Aquasmart WL8065D washer and disappear into the works. Shortly after the machine became very noisy during its spin cycle but still working fine.
Thought that the coin may have found its way into the pump unit and be creating the noise. Do you think this is likely or do you have another suggestion?If the pump how do I remove the pump on these units (ie is it just a matter of removing the 2 screws visible in the base of pump unit and pulling the core out after removing the power connection or do I need to remove the whole pump case from the chasis. )
Thanks for your help.