Prop steer or "torque steer"

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diamondjim

Member II
After 2 1/2 months of full time restoration on my newly acquired 1981 28+, I took the boat to the Yard to paint the bottom (first time in 4years). Before the yard, I installed a new Universal M-18 (Z500 kubota diesel), aligned the engine/transmission and propshaft and the machinery functioned perfectly. There was absolutly no pressure on the helm at any speed and no vibration.
During the stay in the yard, I had to replace the packing gland on the prop shaft which required moving the engine/transmission slightly to make the repair. I moved it back exactly to the same place and after launch, the helm wants to steer to port while under power. Even after repeated re-alignment attemps.

There was plenty of barnacles on the prop which were removed. No damage to the prop was evident. On this boat, the prop shaft sits just a few inches to port of the center line of the keel - therefore the prop thrust is partly on the port side of the rudder. Could this port side helm pressure be caused by a clean prop and bottom? Is this normal while the boat is under power?
 
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gareth harris

Sustaining Member
It is normal on my boat (E35-2). I have been told it is to keep the main prop thrust from going straight into the rudder.
Gareth
 
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Merchey

Junior Member
My E27 has tremendous rudder pressure to port under motor power increasing with speed. I can’t let go of tiller without an immediate 90 degree turn to port. Under sail at same speed with sails balanced, no such pull. I have a tiller clutch that sometimes will allow me to let go for a short period of time. I’ve been told it’s just because of the turbulence from the prop close to leading edge of rudder and the shaft being slightly off center.
 
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HerbertFriedman

Member III
My 1987 E34 also has a strong pull to (bow) port under full engine power, so much so that my auto pilot cannot keep a straight course but swings widely from side to side. But strangely enough, in reverse I notice little or no prop walk of the stern to port. Any explanations welcome.
 
toddster

toddster

Curator of Broken Parts
Blogs Author
If I must "hand steer" under power at cruising speed (usually because of traffic or narrow channel) I usually just lean into the tiller with my hip.
It's a 70's boat. Likes to boogie.
 
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