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.
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.