Mercruiser steering shudder

[orca]

G,Day. I am having a problem with a V6 mercruiser sterndrive 2000 model. When the wheel is turned full lock there is a severe shudder or vibration felt through the wheel, I have checked the universal joints and replaced the gimball bearing. I have ran the motor with the power steering belt disconnected and there is no vibration, any ideas?. Thanks guys.

[Richard Petersen]

Was the belt tight enough originaly ?

[trog100]

thinking about it.. it must be the limitter valve in what i would call the power steering rack if it was automotive.. never looked at boat power steering to be honest but i imagine the principle would be the same.. the valve shutting on and off rapidly would cause feedback thru the wheel..pure guesswork this one by the way.. trog100

[bigbrownbuku]

look at your power steering ram, on the narrow section there is a machined slot , this should be staight up and down. if this is correct start the engine and get someone to steer while you observe what is going on. if the ram shudders it is likely at fault, you should notice the shuttle moving smoothly in and out as direction changes. if there is any corrosion in this area that is bad(the shuttle is the larger 2 peice section where the pivot bolts to the t plate). also check your oil level, cold and warm. full lock is not something most rams like to do, kind of like the squeel you hear in your car at full lock. if all of the above checks out its likely ok. also check your power steering belt isnt loose.

[orca]

G,day. Thanks for the input guys, the belt is OK ant tightened correctly, I will check the shuttle. The boat appears to have been built around the motor and it is hard to get to the ram.