Trojan Boat Forum

Yesterday we went out and on the way out to the cove I stopped to pump out for the weekend(my neighbor said I had a stinky boat).
We pull up to the gas dock beautifully and pump out and I am ready to go.
Start the engines, put it in gear and start pulling hard to the starboard side. Not the direction i was trying to go.
So I retie up to the dock and go into the basement. Can't see anything wrong so after some cable investigation and lookingat everything I figure I will just take us out to the cove and check it out once everyone else is in the water.

We get to the cove, it's hard as he!! to steer into the cove and turn around and back up on one screw. So anyways, when I got everyone settled into the water, I go back into the basement and see the starboard shaft is half way out of the rear of the boat. Not good. Turns out the bolts that clamp the shaft into the coupling on the back of the transmission are stripped out. SO long story shorter, I have to go Thursday night before the 4th and drill and tap the new threads in it to hold the shaft in. PAIN in my rear.

Sorry to hear about your problem but that's boating!!, also the basement as you put it is actual called a bilge.

willietrojan wrote:Sorry to hear about your problem but that's boating!!, also the basement as you put it is actual called a bilge.

My fault, I am still getting my terminology down. Yep, it is boating, just never had a shaft fall out before

Be thankful it didn't snap and fall out completely and flood your "basement". The rudders are what kept it from coming all the way out. Otherwise, you'd have a real problem! Good luck on the repair!

Stripermann2 wrote:Be thankful it didn't snap and fall out completely and flood your "basement". The rudders are what kept it from coming all the way out. Otherwise, you'd have a real problem! Good luck on the repair!

Yea, no doubt. Come to find out that it happened to the previous owner before as well. Same side, same shaft.

Be careful with this repair. On a straight shaft, the coupling is supposed to be press fit onto the shaft. The set screws are not intended to support the shaft torque on their own.

I replaced the shaft in my F26 a couple of years ago (due to corrosion) while I had the engine out of the boat, I removed the shaft with the coupling still in place by removing the prop and pulling the shaft through the stuffing box from the inside and used a slide hammer to remove the coupling from the shaft. I sent the old coupling out to the shop where I ordered the replacement shaft, but they said the inside diameter of the old coupling was too big to create a tight enough fit on the shaft so I had to replace the coupling as well.

Here is some reference info from the web.

There are two basic propeller shaft designs, single-taper drive shafts and double-taper drive shafts.

Single-taper shafts are tapered only on the propeller end. They are press fit into the coupling and secured with set screws. Since the diameter of shafting can vary by up to .004”, single-taper shafts and couplings should be replaced as a factory matched set. This will prevent an improper fit, which may vibrate loose and cause major damage to the boat. Double-taper shafts are tapered and threaded on both ends of the shaft.

Single-taper shafts are pounded out with a slide hammer or cut in two at the coupling. The slide hammer method is time-consuming, laborious, and detrimental to transmission bearings and seals. Cutting the shaft is relatively quick and easy, but is not an option when the shaft is to be reused.

Good Luck
Chuck

Yea, it seems to be a hassle no matter what I do. My father and I are going to tackle it tonight. It's really a piss-poor design. TO me there should be a pin through the shaft maybe just a U-Joint instead of that coupling. I don't know but the torque of putting the boat in reverse and pulling on those shafts is really too much for the way they have it mounted in there.

If it makes you feel any better, I have a '72 42' sea voyager and this happens to me on my port engine EVERY year at least once. Last year, the threads were so worn out on the coupling that I had to get a new one and the mechanic put on a new coupling ignoring the fact that the set screws did not match the indentation on the shaft - that lasted just until I got it out from the dock the next day. I ground new, deeper grooves onto the shaft and it held for the rest of the year. Of course this year, I neglected to check the coupling and within two weeks of launching, out it came. In my experience, the bolts shear off from vibration, I assume because it is a two piece propeller shaft and in a 35 yo old wooden boat, things get a little sloppy. I now will be checking the coupling once a month since it is a real pain to haul the shaft back into the boat with a stillson wrench while scrunched up behind the engine. Oh the joys of old wooden boats.

Wingit48 wrote:If it makes you feel any better, I have a '72 42' sea voyager and this happens to me on my port engine EVERY year at least once. Last year, the threads were so worn out on the coupling that I had to get a new one and the mechanic put on a new coupling ignoring the fact that the set screws did not match the indentation on the shaft - that lasted just until I got it out from the dock the next day. I ground new, deeper grooves onto the shaft and it held for the rest of the year. Of course this year, I neglected to check the coupling and within two weeks of launching, out it came. In my experience, the bolts shear off from vibration, I assume because it is a two piece propeller shaft and in a 35 yo old wooden boat, things get a little sloppy. I now will be checking the coupling once a month since it is a real pain to haul the shaft back into the boat with a stillson wrench while scrunched up behind the engine. Oh the joys of old wooden boats.

Ahhh, so I see you feel my pain. I am gonna drill and tap a larger case hardened bolt into it tonight and pray that it stays. I am also going to put some thread tape on it so it will stay in there a little better. Hopefully I will be successful. Wish me luck

Might use some LocTite as well ...

Good luck! We spent July 4th in the harbor in our tender, since our upper helm throttle port throttle cable broke. Didn't use much fuel though!

I have the same boat 1974 44', my shaft came out 2 weeks ago when going into reverse. When I went to reinstall the 2 set screws I noticed the holes don't line up with the shaft so I put 1 back in. How difficult is drilling a stainless shaft for the 2nd bolt?

Ok, well we got it fixed really well this go-round. We(Dad and I) got out there late Thursday night and pulled the shaft out of the yoke and drilled the stripped bolt out clean and then re-threaded it out to a M10 Metric bolt for more threads. We then removed the one good bolt that was stuck with vise-grips and then sprayed it with lube and ran it in and out of the threads a couple times to make sure it would engage the shaft properly, then finally where the bolts vise onto the shaft Dad bought a new carbite drill bit and dippled the shaft really good to inset the bolt tips into the shaft where they would seat well. Finally loc-tite on the bolts and they held really well all weekend.
Dad was ready to tack weld it onto the yoke if this doesn't work. This is the 3rd time it has come out and the stripped bolt was annoying but we seemed to have got it this time.
Now I have to go and buy the proper electronic ignition for the Onan and then the big things will be fixed.