Lower Crank Seal

[Big Jay]

Hey guys, I picked up a spare '57 18hp for parts and have been cleaning it up so it's not nasty to work with later, as well as to make sure everything is ok on it.

When I popped the powerhead off the leg however, I found this laying in the baffle:


Is it as simple as replacing these 4 parts and being done with it? The area is dry and free from oil, and looking into the crank cavity I see no damage...

Also, can you explain the purpose of these parts?


Thanks, the crank and it's seals and how it all goes and works together is a new frontier to me

 

[AlTn]

Re: Lower Crank Seal

marineengine.com..your motor..crankshaft group..#9 snap ring is your's broken?..#10 your's is missing..#11 spring..your's is broken..#12 your's may be ok, hard to tell...#13 carbon seal..if your's isn't chipped or crack possible to reuse, your call..#14..oring that fits in a groove in the rubber seal...just replace it...the carbon seal/oring combo slides on the crankshaft and is held in position by the spring setup secured with the snap ring < another set of fingers to compress and hold that spring in place while putting the snap ring on is helpful >.. I believe the carbon seal end with the "notches" goes against the bearing, but suggest confirmation on that before installing

 

[Big Jay]

Re: Lower Crank Seal

Thanks a lot!

The carbon seal seems fine, but the rest will need replacing I think. And I am missing #10, thanks for pointing that out.

What would cause failure in these parts, just normal wear and tear?

 

[F_R]

Re: Lower Crank Seal

The side of the carbon with the notches does not go against the bearing. The other side has a raised ridge that rides against the bearing. That seal assembly is vitally important in keeping water out of the crankcase Water in the crankcase will rust the bearings, which is a death sentence to the motor.

 

[Big Jay]

Re: Lower Crank Seal

Wow... ok

Phew:cold:... how do I check the crank bearings for rust?

Through the other side of the reed block/intake?

 

[AlTn]

Re: Lower Crank Seal

thanks F_R for clearing up that doubt < smooth side up > on the carbon seal...since you have the powerhead off you're not that far from pulling the intake side of crankcase off and inspecting Big Jay...

 

[Big Jay]

Re: Lower Crank Seal

Indeed, thanks F_R...

And thank you AlTn, I am however having an issue getting the reed block to let go. The intake came off with a light tap of the rubber mallet, but no movement on the other.

Is there a trick to this? I don't want to hurt anything

 

[AlTn]

Re: Lower Crank Seal

1 screw in the center and those around the perimeter is all I recall

 

[geoffwga1]

Re: Lower Crank Seal

1 screw in the center and those around the perimeter is all I recall

Don.t overlook the flat head screw on the extreme port side.

 

[F_R]

Re: Lower Crank Seal

Take a close look at the bearing where the seal came off from. See any rust?

 

[Big Jay]

Re: Lower Crank Seal

No, everything looked surprisingly clean... almost new looking...

This is a good sign ? ray: