which crank seals do i have

[The red boat]

This is the crank of an RD-17S that i’m working on.
I’m aware of the crank seal problem but unsure of how to identify what I have here. good seals or evil seals?

Also if these are the bad seals, is there a procedure detailing how to remove and replace them somewhere?
parts numbers would be good if someone has those handy?

thanks

• This topic was modified 4 years, 3 months ago by Mumbles.

[Mumbles]

Your motors serial number will verify what you have and it looks like your motor has the troublesome lip seals. There was a mid year change on the seals and the earlier ones were the carbon/O ring style which were replaced by the lip seals. Somewhere down the line OMC realised the lower lip seal wasn’t cutting it and they went back to the carbon style seal.

I can’t find an RD 17 parts manual but this ’55 Big Twin manual shows the difference between the two styles of seals and whereabouts in the serial numbers it happened. At least for the Evinrude Big Twins.

55-Evinrude-25-hp-Electric-Parts-Manual

Here’s are ’56 FD and a ’56 RD lower lip seals as found when the powerheads were removed.

[outboardnut]

Frank – correct me if I am wrong but
Replace the top crank seal with the same parts as RD-17S
As for the bottom seal which matters because of water
Replace parts using the parts numbers from RDE-17 parts list
The bearing will be smaller in height
You have to break open the block if you want to replace like in the picture of the RDE-17

[outboardnut]

[outboardnut]

For number 6—- use quad ring 305098 instead of o ring
The quad ring will go inside of the carbon seal

[The red boat]

that helps a bunch – thanks!
i can see it now.
so is it your opinion to leave the top seal alone?

[outboardnut]

If your opening up the block to do what is in the RDE-17 parts list for the bottom seal
You might as well replace the top seal
You could use either seal method you want for the top seal
Call me if you want to talk
Al 630-624-8382
We have spoken before

[The red boat]

in the RDE-17 – so when replacing that bottom seal, do I also need nos. 2, 3, 4, and 16 as well as the carbon seal and quad ring?

[outboardnut]

you need
7
15 o-ring
6 quad ring 305098
5 carbon seal
4
3
2
16
To do all this-you have to open the block
call me if you want-my number is listed above

• This reply was modified 4 years, 3 months ago by outboardnut.

[Mumbles]

Before converting to a carbon seal, make sure the crank has a groove machined in it for the #16 snap ring. Some do, some don’t.

[Author]

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