Bent Rudder. Repair?

Yes, it can be straightened. Someone will post a recommended shop soon.

Thanks

Ben, the folks at site sponser Delta Prop can do it. They straightened out a bent rudder shaft for me a few years ago. Give them a holla and tell em' what you got and that you are one of us and you'll get a discount too. Give back to those who help support the site.

dwouncmd wrote: I can't really tell if it is bent.

The shaft needs to be set up in a set of V blocks and then check it with the dial indicator.

SNobsessed wrote: I bet Pete was thinking about a prop shaft in his reply above, which has to be straight within .003 inch.

Chris,
I really was thinking rudder shaft but just went to the extreme! Your "kitchen counter" method will work as well but it's just not as accurate. The straight edge and feeler gauge would be better.

I've never measured the clearance in a rudder port but if I had to guess, I'd say it's around .005". That a lot of clearance in a bore. So, if the rudder shaft is bent beyond that, I'd say it would bind in the port.

Can you put it back up in the port & manually determine where it is binding?

Edit - I looked at my boat & there is a machined shoulder at the transition. I think that could be gaged with a square.

Ben, welocome to the site. Let me know if you need some help.

I sent the rudder to Delta and got it back this week. I went to install this a.m. and head to the lake but it will not go into the housing all of the way without binding. Once it drops about 1/2 inch it spins easily but I am pretty sure that is not right. I am now wondering if it was straightened correctly or if the rudder housing is bent as well. Rudder shaft still does not look right and the rudder itself still looks bent but I am no expert. Any thoughts?

I bought the dial indicator at Harbor Freight, but still haven't figured how to set it up to check for true...

ben.b wrote: I am now wondering . . . if the rudder housing is bent as well.

I think this is a strong possibility since the impact force had to get absorbed somewhere. If you can find or make a square with a long thin blade, this could be easily checked. The tube should be square with the hull flange, within the rudder OD / port ID clearance.

Thanks again for the advice.

It just so happens I have a spare rudder port, so I set it up with the shaft rotating in the port and the dial indicator clamped to the port, which was a little fussy, but I got it to work.

So, it sounds like Ben and I now have the same problem. The shaft seems bent as it mates with the rudder.   According to the dial indicator the bend in the shaft starts about 1/2" from the rudder and the shaft appears to be bent mostly aft, but also to one side slightly. At its worst, closest to the rudder, the shaft deflects .040". Interestingly, there are some wear marks further up the shaft, and I think it is about .010" out of true, but does not bind in the port. As the shaft is inserted deeper into the port, the binding begins, about 1/4" from the rudder. I can recreate the same binding I felt at the helm when the rudder was still in the port that is still in the boat, with rudder binding sooner turning to port. If I try to insert the shaft all the way into the port, abutting the rudder, it is completely frozen.

With the binding going away with a little shaft showing, I wondered if it would be possible to adjust the port to have the rudder that extra 1/4" or so out of the port.

If having an extra 1/4 inch of shaft showing is a bad idea, to have the shaft successfully straightened, would it help to send the port and rudder together?

I had a slight bend in mine earlier this year. At speeds above 25 mph the rear end would walk side to side a bit. I think it had to do with pressure building up on one side then releasing, happening over and over. It didn't seem too bad from the driver's seat but my wife said it was terrible from the rear seat. When I first reinstalled the repaired rudder I over-tightened the packing nut so I had too much friction on the bearing. I dropped it 1/16-1/8" and it operates almost too smoothly now.

I still like the idea of getting some lapping compound in the assembly and seeing what it will do!

Ben,
It's great to hear that the rudder problem is fixed. Now, get out there on the water!

I got off early from work today, so I had time to get the transmission out. Now it just needs to be boxed up and sent to Fantastic Finish Marine for a rebuild. While everything is in pieces, I think I am going to bite the bullet and switch to a double taper shaft...