Super Jet Packing crank seals

[Pablo]

Do you guys pack grease between your two rear crank seals? I know to grease the inner lips where the crank shaft goes through the seals. More than that I was unaware.

 

[Freakrider]

No, it's not needed...

 

[McDog]

Im being told by a respected engine builder that it is a must and my bottom end assembly without it caused the seals to fail allowing air in to toast pistons and water in to ruin the crank on a motor I sold. I would love to see some discussion about it.

 

[Mark44]

I pack that area with grease.

Mark44

 

[Pablo]

When u say u pack it, are you filling the entire void between the seals with grease? Marine grease or what type?

 

[RoTAxGreNade]

The service manual doesn't call for it - just to grease the lips and cover the threads when sliding the seal on the crank.
It's one of those individual preferences like using 1211 on the crank seal to case areas...

 

[SuperJETT]

It doesn't hurt anything, and only takes 30 seconds, so do it. I always did.

 

[McDog]

Shop manual didn't call for it. This is the first I have heard of it and it's costing me a few hundred dollars to make it right.

 

[DirtyJ]

I was always told to pack the seals with some good marine grease. Like JETT said it only takes a min!

Sorry to hear about your luck though McDoggy.

 

[Waternut]

I've always used it. In the past when I heard about it, there was still a debate. The way I see is this... The grease can't cause an issue since that area is supposed to be sealed. However, because the crank seals are rubber, they can allow water and fuel to pass through them. In this scenario, the grease helps minimize the amount of water and fuel that can enter. The grease would also act as a heat sink for the seal keeping it cool. Maybe that's a garbage reasoning but I haven't fried any crank seals having the grease between them.

 

[McDog]

I wish you told me that last year.

 

[SUPERJET-113]

I used to for about 10 years... but havent in like the last 10 years.. with no problems.
They dont come from the factory with that void filled with grease and the manual does not call out for it as mentioned..
IMO, not needed if you have good seals and they are put in correctly, but you can if you want.
But yes, grease the "lips" for sure....yeah baby!

 

[Cranes]

I like greasy lips

 

[McDog]

Am I at fault for a new crank and top end and shipping and gaskets and seals if a motor I sold was assembled without it and the seal failed? It wasn't in the shop manual to do it but I want to do the right thing. I also would rather not spend the money either if it is something that just happens sometimes whether you pack it with grease or not.

 

[Waternut]

Am I at fault for a new crank and top end and shipping and gaskets and seals if a motor I sold was assembled without it and the seal failed? It wasn't in the shop manual to do it but I want to do the right thing. I also would rather not spend the money either if it is something that just happens sometimes whether you pack it with grease or not.

First off, if the manufacturer doesn't require it, then it's not necessary and therefore can't be at fault for causing any problems. It might be beneficial to do something the engine manufacturer doesn't require but that still doesn't make it a requirement. If Honda said to change the oil in their car every 7500 miles, they can't deny your claim because you didn't change the oil every 3000 miles.

Now, if an engine I sold to someone died a couple rides after I shipped it, I'd probably feel guilty and either buy the engine back or pay for the parts to rebuild whatever broke initially. Once that's taken care of, your obligation is over. I don't know of too many reputable shops that would warranty a performance engine for any period of time whether it be for a dirt bike, jetski, or car. Then to find a shop out of that small group that will warranty a used performance engine would just be unheard of. I don't see Team Scream or DASA list any warranties on their brand new engines. I have no doubt they will help you out with questions but the purchase price doesn't include rebuilds for life.

 

[FlightRisk]

Im being told by a respected engine builder that it is a must and my bottom end assembly without it caused the seals to fail allowing air in to toast pistons and water in to ruin the crank on a motor I sold. I would love to see some discussion about it.

I had the opposite experience last year, I toasted a crank seal on a motor I had just rebuilt with grease packed in between the seals and ruined a new top end.

I blame it on aftermarket crank seals (I didn't know they were aftermarket at the time). Were your seals aftermarket?

 

[McDog]

No. They were oem if I remember correctly.

 

[RoTAxGreNade]

A seal will only fail on a new motor from nicking the lip surface on any sharp edges/ threads during assembly or a piece of grit or dirt along with no assembly lube. Barring a grooved or nicked crank.
The seal lips are lubricated by capillary action with the fuel oil mixture and I'm sure positive crankcase pressures will help that process also - I can't see 2 stroke oil or grease used upon assembly alone is enough to keep the seal lips lubed it's whole service life.

 

[tor*p*do]

I packed grease into the small u on the lips
but there really isnt much room to pack much grease between oem seals when installed

 

[kevbo]

The rear seal needs to get lube from somewhere or it will burn up. Some engine oil will get past the first seal and eventually make its way out the rear. Adding some grease to the gap just fills the pipeline. Kawasaki has been doing it for a long time.