Very hard to steer towards starboard while underway

[theorifice]

We have a dual 5.7 Alpha 1 Gen 1 sterndrive boat.

Took the boat out today and once underway at cruising speed (~2000 RPM) I found I could not turn the steering to starboard. I immediately got into neutral and found that steering returned. I found that only steering to starboard was affected with the stiffness proportional to RPM. I did not investigate further with only a single engine running as I had family with me at the time. Last weekend, the steering was working as expected.

I believe the helm unit is a rotary style. I'll be back at the boat this week and would like some help knowing what to look for for the one sided power steering symptom.

Additionally, I feel that there is a lot of play in the steering. I don't have a lot of experience with boat steering systems. Is the play in the video OK or is there something else to check into?

Thanks,

 

[Fun Times]

There are a quite a bit of components throughout the whole steering system that could cause this affect and depending on actual issue, it could take some time in testing to narrow it down... The service manual goes through the process of testing pretty decently so you may want to also consider getting/finding one as it may help your cause should we by chance not be able to pinpoint your issue here on the forums.

That mentioned, my always first go to on not being able to steer at speed is have you done any service work to the sterndrive since your last outing? Such as a sea water pump impeller inside the stern drive? If yes, do you have a fin styled zinc anode that might not be adjusted correctly now?

Martyr Anodes Mercury/Mercruiser Trim Tab Anode, Zinc

Always check propeller clearance after installing new trim tab anodes.

www.iboats.com

 

[dubs283]

Agree with fun times and will add that a rotary style helm for a sterndrive is not the preferred setup. If indeed there is a rotary helm/cable it would be in your best interest to upgrade to rack/pinion