How to fix a broken lower unit? Advice needed

[northernmerc]

A friend borrowed my fishing boat and left it in the water at the dock with the motor damaged. He hadn't noticed the damage, but I immediately saw it after loading the boat on the trailer. It's a 30 hp Johnson, 2000 model year.



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As you can see by the picture, part of the lower unit is broken off. Once I asked my friend about it, he mentioned that he hit a submerged vinyl/cloth barbecue cover. It seems that it wrapped around the prop until the motor stopped. Possibly the force of the jammed barbecue cover was enough to break the fin off the leg. Maybe the cover hooked on the aluminum thing that projects below that piece (above the prop) and broke the piece off.

It does not leak oil, and the motor runs again. But the lower unit looks terrible, and it will hurt resale value if I ever want to get rid of this motor.

The break is right through the bolt hole used to hold on that little aluminum fin that goes down above the prop. That piece is also missing.

The prop also sustained a lot of damage, with big chunks knocked out of it. But I fixed that. It also came back with lots of fishing line wrapped around the prop and inside the prop. The oil in the leg looked milky when I drained it, so I probably will have to replace the seal on the prop shaft.

I've wondered about welding in a piece of metal on the lower unit and then painting the repair. I have virtually no experience at welding aluminum, although I'm pretty good with steel. I have an AC/DC arc welder, a MIG welder, and an oxy-acetylene unit. Any advice on welding this? Rods or wire to use and fill material to replace the broken piece?

Or would it be better to look for a used lower unit? A new piece would cost more than the motor is worth.

 

[Joe Reeves]

Re: How to fix a broken lower unit? Advice needed

Drop the lower unit and take it to any reliable propeller repair shop. They'll heli arc a section on there and file it down so that it will look like new, after which you can prime and paint it.

 

[jasper60103]

Re: How to fix a broken lower unit? Advice needed

That sucks. Hopefully your friend will cover the repair bill.

 

[Tim Frank]

Re: How to fix a broken lower unit? Advice needed

A friend borrowed my fishing boat and left it in the water at the dock with the motor damaged. He hadn't noticed the damage, but I immediately saw it after loading the boat on the trailer. It's a 30 hp Johnson, 2000 model year.


As you can see by the picture, part of the lower unit is broken off. Once I asked my friend about it, he mentioned that he hit a submerged vinyl/cloth barbecue cover. It seems that it wrapped around the prop until the motor stopped. Possibly the force of the jammed barbecue cover was enough to break the fin off the leg. Maybe the cover hooked on the aluminum thing that projects below that piece (above the prop) and broke the piece off.

The break is right through the bolt hole used to hold on that little aluminum fin that goes down above the prop. That piece is also missing.

The prop also sustained a lot of damage, with big chunks knocked out of it. But I fixed that. It also came back with lots of fishing line wrapped around the prop and inside the prop. The oil in the leg looked milky when I drained it, so I probably will have to replace the seal on the prop shaft.

Joe Reeves nailed it....no surprise there....

I am not sure that you are getting the whole story from your buddy.
That amount of damage seems inconsistent with hitting just a BBQ cover.....unless the BBQ was still inside it....

 

[northernmerc]

Re: How to fix a broken lower unit? Advice needed

Drop the lower unit and take it to any reliable propeller repair shop. They'll heli arc a section on there and file it down so that it will look like new, after which you can prime and paint it.

Thanks for the suggestion. Is heliarc the same thing as TIG?

I'm wondering what the repair shop would use for a piece to weld on. Is aluminum in this thickness a common item? Or would they need a donor leg to cut if off of?

 

[wilde1j]

Re: How to fix a broken lower unit? Advice needed

Take to a shop familiar with lower unit welding. Nothing special here, just a piece of aluminum plate, which any shop should have and some grinding. The prop should go to a prop shop for repair. Neither are DIY repairs, unless you want to risk wrecking stuff. And your 'friend' should pony up for the bucks. Shops that weld on lower unit most commonly weld on new skegs, but this is also an easy one.

 

[northernmerc]

Re: How to fix a broken lower unit? Advice needed

While I'm at it, I should look for the source of the water in the lower unit. Oil isn't leaking out, but the gear oil looked a little milky.

My suspicion is that the fishing line that wrapped around the prop took out the seal on the propellor shaft. Does that sound most likely? Or should I look at where the shaft comes out on top of the gear box, pointed at the powerhead?

Can anyone point me to a thread with instructions on replacing the oil seal(s)? A search didn't come up with much.

 

[DJ]

Re: How to fix a broken lower unit? Advice needed

The most common source of water intrusion into Lower Units is the fill/drain plug seals.

Once you have the cavitation plate fixed, replace those seals before you go attacking a prop seal. Do the easy stuff first.

 

[wilde1j]

Re: How to fix a broken lower unit? Advice needed

If you're not sure of the leak source (three - prop shaft, drive shaft, shift rod, plus fill/drain screws), pressure test the LU (no more than 15 psig) with the gear oil drained first. Submerge under water and look for the bubbles. Then have at the leaker.

 

[northernmerc]

Re: How to fix a broken lower unit? Advice needed

I phoned around and found someone willing to weld the cavitation plate. I think the welder saw me coming - what do you think?

The bill came to $137.50. Then add on the can of spray paint and the trim tab that I ordered, and the repair bill comes to $176.32. That's not including replacement of the damaged shaft seals, most likely caused by the generous amounts of fishing line wrapped around the prop shaft.

Someone please remind me not to lend out my boats again! Everytime I do so, they come back with something wrecked.

 

[SolingSailor]

Re: How to fix a broken lower unit? Advice needed

IMHO, if the quality of work is good, you got a very good deal on the welding job. I have tried to become self sufficient in as many boating related fields as possible, because I have found that it is very difficult to find competent repair people, at almost any price. There have been many times I would have gladly just thrown money at a problem (and did), only to have inferior results.

 

[jimdd810]

Re: How to fix a broken lower unit? Advice needed

That dosnt sound out of line for what is needing to be done. good luck!

 

[deperkins]

Prop shaft & shift shaft stuck/ How to fix a broken lower unit? Advice needed

Prop shaft & shift shaft stuck/ How to fix a broken lower unit? Advice needed

I have a 2006 Mercury 90 EFI 4-stroke that lost oil drain plug and I need to replace the bearings and seals, however I cant get the propeller shaft off I have removed the thrust hub and reverse gear but the shaft is stuck the lower housing had seawater in it and was corroded. I have been able to loosen things up with PB blaster. But cant get the shaft out?

I also can?t get the shift shaft out any suggestions on that also?

 

[wilde1j]

Re: How to fix a broken lower unit? Advice needed

deperkins, don't hijack this thread ... you're in the wrong place anyway. This is only Johnson Evinrude

 

[Joe Reeves]

Re: How to fix a broken lower unit? Advice needed

Northernmerc.... $137.50 sound good to me. Back in the 1980/1990s, repairing a skeg or cavitation plate would be about $70/$80..... fast forward 20 years or so, not too bad.

 

[bktheking]

Re: How to fix a broken lower unit? Advice needed

Someone please remind me not to lend out my boats again! Everytime I do so, they come back with something wrecked.

Loan it out, $1000 deposit, $900 cash back upon return with no damage.

 

[northernmerc]

Re: How to fix a broken lower unit? Advice needed

The fellow who welded it up did an OK job. It will pass a casual inspection. The repair does show from above, even through a few more layers of new paint. And the recessed part underneath, for the trim tab, isn't recessed anymore. I ordered a new trim tab and hope it will fit OK. If not, I'll have to get out a small grinding wheel I suppose.

It's certainly better than it was, and I know that welders charge upwards of $100 an hour.

Northernmerc.... $137.50 sound good to me. Back in the 1980/1990s, repairing a skeg or cavitation plate would be about $70/$80..... fast forward 20 years or so, not too bad.

 

[Joe Reeves]

Re: How to fix a broken lower unit? Advice needed

The ones I had heli arced came back looking like factory minus paint. Was this a marine propeller repair shop?

 

[northernmerc]

Re: How to fix a broken lower unit? Advice needed

He does a variety of welding, including props and legs. As far as I know, he used a TIG welder, which I believe is the same thing as heli-arc.