First, I would check for the obvious.... is your steering wheel rubbing the helm?
Is your outboard properly greased?.... is there any restriction?
A subtle, rapid clicking noise, while turning the wheel, is normal.... "squeeking" is not.
Last thing I can think of is, bleed, (purge any air out) the steering system, at the cylinder.
Seastar link;
http://ww2.seastarsteering.com/OUTBOARD ... urge.htm&1
Usually, tightness in the steering, (at each end), skipping, or "chatter", is an indication of air in the system. Not sure about "squeeking", but it's worth a try.
