Owners of 312's with omc cobra, CAUTION BEWARE!!

[ncup40]

At the lake yesterday running just below wide open throttle when the power steering belt broke. The boat turned dead left, we were lucky, no other boats close by. The G force was incredible, everything and everyone was thrown to starboard side and held there. My mind was processing a million things all at once as I was struggling to overcome the G's to get to the throttles and go to neutral. Now granted, this whole event probably lasted no more than 10 seconds, it was still terrifying.

Whether it's engine torque or prop torque that causes this I don't know, this happened with no steering wheel input. Please don't get complacent at high speeds with omc cobra sterndrives. We were lucky, you might not be. Everyone please be careful.

[2216terry]

The lack of power steering at high speed would not make you hook the boat. some other thing must have taken place. the fact that the boat has O.M.C. power has no bearing on what happend.. I bet something broke in steering and made the belt come off.

[ncup40]

Had it not happened to me I would agree with you 2216terry. When the power steering belt broke it also knocked off the alt belt. I carry 2 spare alt belts but no steering belts. Put new alt belt on to run the waterpump, and decided to call it a day. It was about 2 miles to get to the marina, and what I noticed was when under power to get to plane it pulled hard left, and when I throttled back after planning it darted right. Very hard to drive without power steering. After I got it home started investigating, lots of rubber powder everywhere including caked on both flame arrestors. The new power steering belt I had put on the week before was too wide for the narrow groove pulley. As the rubber wore away the belt became loose and that initiated the sequence of events. I then noticed a trim tab missing from the port lower gear case, which I understand is to counter the pull left or right from prop torque. I then discovered a volvo penta steering ram with 1 to 2 inches of side to side play. More confused than ever at this point.

[stinger390x]

Sorry to hear about your issues...

I too agree with the other gentleman that the belts have no issues with steering. The tabs will also not give much issue with steering as it is used to stabalise trim not turning. A sudden loss of steering pressure may acount for some stiff steering but by the sounds of it a bad ram would probably be the cause of steering going ramant if it failed? A loss of hydraulic fliud would cause a sudden collapse or extension(depending which way it broke?)

You mentioned free-play in the ram or steering systm? Could you elaborate!
I think you may have issues with the steering system itself and not from any belt breaking issue.
You said its a 312 so I take it for granted you have twins under the hood? Do you have a tie-bar between the two drives?

My 390 has a tie-bar but my 260 didn't. I put one on my 260 and it made so much difference I cannot begin to tell you how happy I was with the performance after that!
Another thing to consider is aftermarket or upgrade your steering. My 390 has "Latham" steering is absolutely top knotch!

[NWC]

I could see this happening if your drives were not counter rotating.  You would really feel the torque of the drives without the power steering.