1968 3.9hp corroded drive shaft

[mattdd]

the drive shaft on my outboard is corroded around the water pump seals....which is apparently common on these motors. i've followed up on all suggestions i've read here and else where, but no luck. the speedi sleeves that some use to repair the seal area do not go small enough for my application. my shaft diameter is .455 and i believe the speedi sleeves only go to .471, unless someone can correct me. the machinists at work said they would look at repairing the shaft so i tore down the LU and pulled it out, but they said they cant do anything and adding new material would heat it up and run the chance of warping it. are there any other options? what about smoothing out the seal areas with an epoxy, and then sanding to the correct diameter?

 

[Faztbullet]

Re: 1968 3.9hp corroded drive shaft

I have had customers with the 20hp motors have theirs silver soldered with success..

 

[Chinewalker]

Re: 1968 3.9hp corroded drive shaft

I've used Marine Tex to fill the rough spots and it seemed to work short term. Long term - I don't know how it'll hold up, but we'll see...

 

[mattdd]

Re: 1968 3.9hp corroded drive shaft

I've used Marine Tex to fill the rough spots and it seemed to work short term. Long term - I don't know how it'll hold up, but we'll see...

how long have you been using it with the epoxy? which color did you use...from their website it sounds like white has the most adhesive strength. did you just build it up in the seal contact areas and sand it back down?

 

[Chinewalker]

Re: 1968 3.9hp corroded drive shaft

I used the white Marine Tex... it's been on there about 6 years, but the motor doesn't get a whole lot of use anymore (1969 Merc 35 hp), maybe 8-10 hours a season. Oil is a little milky, but not like it was when it was pretty much pure water when I drained it...

 

[mattdd]

Re: 1968 3.9hp corroded drive shaft

I got this project finished up last week and the epoxy fix seems to be working well. Ran it in a barrel for 30 min and the oil came out a little discolored but def not milky. Also took it out on the river and it worked great. Really moves my canoe. There wasn?t a lot of info out there when I started this project so for anyone else that is looking?.i pulled the drive shaft, cleaned up the corrosion by putting it in a hand drill and sanding as if it were on a lathe. Filled in the corrosion/grooves with Marine Tex white epoxy and sanded on my lathe again ending with 2000 grit. Then reassembled the LU with new seals.

 

[Laddies]

Re: 1968 3.9hp corroded drive shaft

We have a local hydrulic shop repair shafts or use a seal sleeve.