More Fun!!! Bent Prop Shaft

[CRB357]

I hit something hard coming out of a canal doing 4mph. Propeller wasn’t too bad and I had it fixed already. Didn’t notice prop shaft until I put propeller back in this morning. I tried bending it with a 3ft cheater pipe. I literally jumped up and down on it to no avail. What sort of money is this going to cost to have it replaced? I have no idea, but it feels expensive. Thanks
View attachment IMG_4427.mov

 

[flatheadsteve]

You didn't say which outboard but the shaft and new seals will set you back $2-300. Hate to give you more bad news but if it bent the prop shaft there's a chance the lower sustained internal injuries.

 

[CRB357]

2005 Yamaha F90. From what I've seen, it looks like a big job removing that shaft.

 

[flatheadsteve]

I'd expect a shop to quote you around $500 in labor maybe more these days. It's not easy similar to rebuilding the entire lower. You'll need a good manual to make sure everything is aligned within spec if you attempt yourself. It's a common outboard sourcing a used lower may be cheaper or an outboard with a burned up power head.

 

[LDUBS]

I can't be of much help @CRB357 but son of a gun. That was a lot of force to bend the prop shaft like that. I thought these rubber hubs were supposed to prevent stuff like this from happening. Fingers crossed not much other damage and/or you find a decent used LU around your neck of the woods.

 

[flatheadsteve]

I can't be of much help @CRB357 but son of a gun. That was a lot of force to bend the prop shaft like that. I thought these rubber hubs were supposed to prevent stuff like this from happening. Fingers crossed not much other damage and/or you find a decent used LU around your neck of the woods.

At 10mph I hit a underwater rock ledge and it literally twisted the splines on the prop shaft. This was on a 25hp merc 2 stroke.

 

[David Atkins]

Fishing buddy hit similar thing earlier this year and had to go the entire lower unit because of more internal damage that couldn't been seen until they pulled it apart; if you bent the prop shaft you hit something hard.
A rebuilt lower unit cost him with labor 2,000.00, his casing was damaged along with some internal parts that took part of the strain as well or so I was told. He has a Mercury 60 HP

 

[CRB357]

Thank god I wasn’t running!!! I was being cautious entering and exiting cuts/canals bc water so low right now in Basin. Actually I might have been better off on plane now that I think about it.

I’m going to try the floor jack b/t shaft and cavitation plate method and see how that goes. Don’t really have anything to lose trying it.

 

[LDUBS]

Fishing buddy hit similar thing earlier this year and had to go the entire lower unit because of more internal damage that couldn't been seen until they pulled it apart; if you bent the prop shaft you hit something hard.
A rebuilt lower unit cost him with labor 2,000.00, his casing was damaged along with some internal parts that took part of the strain as well or so I was told. He has a Mercury 60 HP

$2,000 - Yikes! If this becomes costly and there is boat insurance, it might be worthwhile to check with your insurer to see if coverage applies.

 

[Pappy]

Submit to your insurance. At that low speed it is more than likely that there is no gear damage inside the Lower unit.
That being said just about every single piece has to be removed to get it out and replace it.
Go to an authorized dealer with a good local reputation and have them work with your insurance company and advise you.
Have done several of these jobs. Service manager and ins. co. will make a determination based on the repair estimate of the dealer service department.

 

[David Atkins]

$2,000 - Yikes! If this becomes costly and there is boat insurance, it might be worthwhile to check with your insurer to see if coverage applies.

He didn't have any insurance on his boat so it was out of his pocket; I said OMG when he told me, I originally was only told about the prop / hub and not the lower unit casing damage when he called me to ask about it, I asked him to check the prop shaft to be sure and he said it looked okay, he changed the hub out (looking for a cheap fix) went back on the water and that's when he called again and said there's a lot of vibration when in gear so I told him to take it to a Mercury Authorized Mechanic to have checked out! You just never know!

 

[LDUBS]

He didn't have any insurance on his boat so it was out of his pocket; I said OMG when he told me, I originally was only told about the prop / hub and not the lower unit casing damage when he called me to ask about it, I asked him to check the prop shaft to be sure and he said it looked okay, he changed the hub out (looking for a cheap fix) went back on the water and that's when he called again and said there's a lot of vibration when in gear so I told him to take it to a Mercury Authorized Mechanic to have checked out! You just never know!

I "liked" your post, but don't really like what your buddy went through. After reading it, I checked out the cost of a new lower unit for my motor. Not cheap. I'm glad I'm normally in deep water.

 

[Lost But Happy]

I'm glad I'm normally in deep water.

Unless you hit a whale

 

[LaqueRatt]

Thank I'd hunt down a parts motor and swap out the entire lower unit. Cheaper and less labor maybe.

 

[CRB357]

View attachment IMG_4440.mov
Well after researching it and giving it a go, looks like everything going to be alright after all. YouTube saved me once again. I’m going to tweak on it a little more and see if I can get it perfect, then put in water today or tomorrow and see how the motor and gears feel. So far I’m pretty pumped this doesn’t “appear” to be the disaster I thought it was going to e.

 

[CRB357]

Basically I found the hi point, set it at 12 o’clock, put 3 full cranks on the jack, let it sit there for 20mins then checked it. Still a little bit of run out. Set it back up and put 2 cranks and let it sit for 15mins. Removed jack and checked it. Run out getting less and less. So I just kept repeating process with less cranks and less time the smaller the run out got. I’m about to check it right now which should be the last time bc it is just about perfect. I’m having a hard time finding high point now bc there almost isn’t any. That’s what we want.

Also I removed trim tab and used a steel plate on top of jack to spread the load out on plate. I’m no genius, I just watched about 4 different videos and followed their process. It worked.

 

[CRB357]

View attachment IMG_4444.mov

 

[flatheadsteve]

I hope that fixed it for you. If you feel any vibrations on your water test back off the throttle immediately or you risk further damage.

 

[Stand Up]

Looks good from my viewpoint. However, only a test run will tell. I hope it works.

 

[LDUBS]

When you first mentioned the floor jack, I thought no way. That is impressive. I hope it took care of the problem. Can't wait to hear how it runs.