Leaky Crankshaft Seal

[svtmatt]

My engine rebuilt at USLC came back with a nasty crankshaft seal leak last summer.  I pulled the engine and changed the seal this weekend, but am not confident that I've solved the problem because nothing looked abnormal or incorrect with the seal I replaced. 

Does anyone have any tips on how to prevent crankshaft seal leaks or tips on how to best install the seal so it does not leak?  Anyone have any idea why a engine that didn't have a leak before a rebuild would have a leak after a rebuild, other than the seal?

Thanks,
MT

[Grape Competition Develop]

Depends on the depth of the rebuild, if cases werent split and bearings, timing chain etc  were not charged on your invoice, then it probably didnt get replaced.  Here is the sticky thing, if the cases were split and they did not replace the seal, the cases pinch the seal a fair amount and cause indentions.  If these 2 indentions (caused by where the case split meets) are not put back in the exact same spot, i could see it leaking.  Did the seal you removed have the vertical lip that only come in the engines from yamaha, or was it the same as the seal you replaced it with?

[svtmatt]

The seal that came out was the same style seal that I installed.

How about installation depth?  How far into the case opening or how far passed the crankshaft should the seal be pressed? 

Thanks for the info.  I hate to just have to hope it doesn't leak when I get the car up to speed on the track.  I'm looking for any and all robustness actions for this seal interface.

Oil leaks suck.

MT

[amp racing]

make sure your breather tube is flowing freely too..

[Grape Competition Develop]

they go in about .150", any more and they can actually get pulled in too close to the bearing and you will have to destroy it to remove it again.  I've never put a seal in without having the cases split, so this is sorta uncharted territory for me.

[VMS Motorsports]

Depends on the depth of the rebuild, if cases werent split and bearings, timing chain etc  were not charged on your invoice, then it probably didnt get replaced.  Here is the sticky thing, if the cases were split and they did not replace the seal, the cases pinch the seal a fair amount and cause indentions.  If these 2 indentions (caused by where the case split meets) are not put back in the exact same spot, i could see it leaking.  Did the seal you removed have the vertical lip that only come in the engines from yamaha, or was it the same as the seal you replaced it with?

What kind of rebuild are you getting if you don't split the cases?

[Grape Competition Develop]

because most people think that when an engine builder touches an engine, it magically gets everything rebuilt.  I see it all the time, i ran  off the customers that would drag in a tired engine and only want a top end freshened up.  They would take a worn out engine, we would make it make another 10-15 hp, so the next logical step is, it blows the side out of it.  And they just payed for a rebuild, so it's our fault.  yet they were the ones who were too cheap to pay to have the whole engine gone through.

[VMS Motorsports]

Gotcha. Thanks for the clarification.
I wont touch one unless I do a full rebuild, guess there are others out there that do