Volvo SX-M Trim Fin?

[skydrol]

I recently purchased a Four Winns 205 with a Volvo 5.0 GXI engine with a SX-M drive unit. I noticed an empty bolt hole at the end of the lower unit behind the prop. I asked the local Four Winns dealer if a trim fin should be installed there, his answer was no. When looking through the SX-M it appears there can either be a plug or a trim fin and bolt installed.

So my question is do I need it? I came across this while investigating a steering issue. I have some play in the steering system that I have narrowed down to the helm unit so I am really not sure if the boat is pulling to one side or the other until I replace the helm next week. I thought I read somewhere that failure to have the fin installed can also lead to prop errosion.

Any thoughts would be appreciated as the trim fin is about $130 from Volvo.

 

[bruceb58]

Re: Volvo SX-M Trim Fin?

Not if you have power steering which I am sure you do.

 

[skydrol]

Re: Volvo SX-M Trim Fin?

I do have power steering.

So can anyone educate a novice as to why you don't need it with power steering?

Thanks.

 

[bruceb58]

Re: Volvo SX-M Trim Fin?

The trim tab is just there to counteract the torque of the drive so you don't need two hands to hold the steering wheel straight. It will naturally want to turn due to the rotation of the prop. With power steering you don't have that problem.

 

[skydrol]

Re: Volvo SX-M Trim Fin?

Ahh, now I understand thanks for the information.