Outboard oil seal leak - update with picture

[Gobble Doc]

I am considering trying to replace the oil seals in a lower unit.  I have not done this before.  It would be part #18 on a Yamaha 40 4 stroke.  Do you guys think I need to remove the lower part of the engine to do this work or can I do this while the motor is still on the boat?  For instance, will hammering in a new seal be easier if the lower unit is removed first where I can put it all on the work bench...? 

Or, is this really difficult and should best be done by a shop? 

[Skillet]

I'd pull the lower unit and put a new water pump impeller (part#20) in there if I was going to that trouble.  Really not a big deal at all to drop it.

Never replaced the outer shaft seal in one of those, but shouldn't be bad.  Take a real close look at the prop shaft while the seal is off and look for any grooving.  Whatever made the seal go bad (like fishing line) might have grooved the shaft as well.  Or if the motor has a million hours on it, the shaft might be grooved.  If so, just putting a new seal on it may not get you where you're trying to go.

 

[Gobble Doc]

Skillet,

Thank you for your suggestions.  I will consider doing the additional work once it is all apart.  I haven't pulled the prop yet but I'm anxious to see if there is fishing line.  Thanks again.  -Neil

[scout/sniper]

Items 16,17 and 18 should be available already installed in the bearing carrier. You have to remove it anyway and you will know that all the prop seals and bearings are new. You might have to buy a special puller to get it out. It took me about 1 hour from start to finish on a 30hp.

[lokidog]

I've replaced the lower unit gears on a 15hp back in the 80's.  I seem to recall it was a fairly easy procedure to remove that assembly from the lower unit housing.  You should try to do it w/o removing the lower unit from the engine as the attachment to your boat will give you something to pull against.

[scout/sniper]

You do not need to seperate the lower unit. I did it with the engine attached to the boat.

[Gobble Doc]

Thanks for the ideas and insight.  Hopefully getting the old seals out won't be a major ordeal. 

[scout/sniper]

Thanks for the ideas and insight.  Hopefully getting the old seals out won't be a major ordeal.

Replace the bearing carrier as a unit, then you don't have to mess with the seals at all.
I think I only paid $50.00 for the whole assembly.
It slides off over the prop shaft, all the gears stay in place.
Good luck.

[Gobble Doc]

I finally got to pulling the prop today.  It was obvious that fishing line had wrapped around the shaft.  It was also obvious that I had shredded the seal.  Looks like I'll be trying to figure out how to get the old one out. 

[lokidog]

Oops.  That could be your problem.

[scout/sniper]

WOW!
1- Take out the two bolts in the bottom of the bearing carrier.
2- Pull out the carrier as a whole unit.
3- Slide in the new carrier over the shaft with all the new bearings and seals.
4- Install prop.
5- Go duck hunting.......Done!