Friendly reminder about crank seals

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Make sure when you're assembling the bottom end of a 701 to apply grease to the crank seals to help keep them lubricated . This step is often missed, there was no mention of it on the tech faq thread about engine assembly

If they aren't greased they wear out prematurely.
 

Big Kahuna

Administrator
Location
Tuscaloosa, AL
Tech Faq section is a collaboration from all different members who have contributed over the years. There is plenty of stuff that is not mentioned there.
 
That's a solid one up there I admit. Even the service manual has just a symbol that indicates you need grease on the seals, newcomers might easily miss that.
 

OCD Solutions

Original, Clean and Dependable Solutions
Location
Rentz, GA
Correct me if I'm wrong but doesn't the manual also show the double seals installed in the wrong order or is one facing the wrong way? ScottS mentioned it the other day.
 

Quinc

Buy a Superjet
Location
California
I also fill in the space between the seals grease. I no longer remember why, but read somewhere on here it was good..
 

Jr.

Standing Tall
Staff member
Site Supporter
Location
Hot-Lanta
Ahhhhh...... Pandora's Box opens........

#Vortex

Please state grease type for the type seal used in various brand pwc? What heat ranges?
But digging deeper, what type seals are these? What type rubber? I can go on?

point being...... while your tip is a good an valid one. Acting like a know it all can and will box you in a corner.
Be careful for what you wish for
 

bored&stroked

Urban redneck
Location
AZ
He merely wanted to make sure people had some knowledge, such as myself who did not grease the seals at the beginning of the summer. I did use a light coat of 2 stroke oil though, perhaps that will suffice?
 

Jr.

Standing Tall
Staff member
Site Supporter
Location
Hot-Lanta
He merely wanted to make sure people had some knowledge, such as myself who did not grease the seals at the beginning of the summer. I did use a light coat of 2 stroke oil though, perhaps that will suffice?


Im not vaidictive! Have no intencion of going any further. Just playing him a little based off last nights exchange and some of todays PM’s

I agree he has a solid point that I see missed often , by motors coming into my shop. Lubrication is one of those never ending debates with no solid answer. Some Lube is far better than no lube. Quality / Brand / type is a debate for another time

I hope he is starting a positive foward trend, and becomes humble. That would be a good thing
 
Im not vaidictive! Have no intencion of going any further. Just playing him a little based off last nights exchange and some of todays PM’s

I agree he has a solid point that I see missed often , by motors coming into my shop. Lubrication is one of those never ending debates with no solid answer. Some Lube is far better than no lube. Quality / Brand / type is a debate for another time

I hope he is starting a positive foward trend, and becomes humble. That would be a good thing

So can you make a suggestion of what grease is recommended on OEM crank seals since that seems to be the standard suggested seal?
Yamaha only lists water resistant grease.

Also if the manual is in error as to the seal orientation that would be a good note to make sure they go in correctly.
 
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Jr.

Standing Tall
Staff member
Site Supporter
Location
Hot-Lanta
So can you make a suggestion of what grease is recommended on OEM crank seals since that seems to be the standard suggested seal?
Yamaha only lists water resistant grease.

Also if the manual is in error as to the seal orientation that would be a good note to make sure they go in correctly.


Ok, while, BK is right, any type grease will work? And as I said, any lube is better than no lube at all.
Lets take it a step further, but Im not going to go into great detail. I have been thru more Bearing clinics
Than I care to think about. Most of these clinics are centered around installation, and service life which includes grease / lube intervals. Seals fall directly into this due to their close proximity to the bearing. These clinics were instructed by SKF engineers.
First off there are two types of Radial Lip Seal materials. Cheap aftermarket seals, like SBT / WSM seals in the watercraft world are made of Butyl rubber. The better seal, or OEM branded seals are made of EPDM, or a thermoplastic synthitic material. Both seals are effected by the grease / friction heat / water slightly differant.
Traditionaly, most bearings / seals are lubricated by a lithium base or Lithium complex grease. This is fine for 99% of the applications. How the grease works is, as the shaft spins, heat is produced at the friction point. The grease in the immidate area turns liquid or into an oil substance. The oil rolls around the lip keeping it cool, and lubricated.
The butyl rubber type is partly broke down by the lithium ( mineral base) and softens. Then hardens when cooled. This cycling hardens the seal and they start cracking in fairly short order, thus have a short service lfe.
The oem seals (EPDM) is not effected by

the heat or lithium and has a much longer life

Lubricants are constantly evolving. Enter Synthitic based. For this, I have become a big fan.
The synthitic Based Silicon greases are even better IMHO.
These synthics handle very high loading applications, have high heat ranges, without thermal breakdown
Long service life intervals, and are highly water resistant.
I personally have been using the synthics for close to 10 years. I have enjoyed very good results.
And have not experianced any seal lubricant related failures.

Two other things worthy of mention. I change seals at every teardown / crank inspection & Never reuse seals.
I always glue the seals into the cases with the case sealant . Espically the rear output seals.

As for branding? There are many. I personally like Mobil Lubricants. But, most all name brands carry high ratings
You do get what you pay for! I dont buy my motor related stuff at Walmart!

For the oriantation question? I made a joke as BK mentioned ........ “Tits Out” If you have ever installed a set of seals
You will know exactly how the joke is refranced !!

Hope I answered what you were looking for?

Ski ya, Paul
 
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