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Discussion Starter #1
Me and my buddy are rebuilding a couple engines. Did a leak down test on one, both crank seals were leaking(new seals). Put 2 new ones in, its still leaking on the left side around the crank shaft. Im kind of stumped here... Its leaking about 1 pound every 2 minutes. Anyone ever ran into this problem? Should i try another new seal or???

On another motor, the tranny spins fine, shifts through gears fine. When i torque the nut on the main shaft holding the clutch, it locks up. I can torque it to about 25 lbs. before it starts to lock up. Is this a symptom of a bend shaft?

Thanks for any help!
 

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Me and my buddy are rebuilding a couple engines. Did a leak down test on one, both crank seals were leaking(new seals). Put 2 new ones in, its still leaking on the left side around the crank shaft. Im kind of stumped here... Its leaking about 1 pound every 2 minutes. Anyone ever ran into this problem? Should i try another new seal or???

On another motor, the tranny spins fine, shifts through gears fine. When i torque the nut on the main shaft holding the clutch, it locks up. I can torque it to about 25 lbs. before it starts to lock up. Is this a symptom of a bend shaft?

Thanks for any help!

Crank seals, will normally weep some between the crank & seal lips, but not a great deal. Thats how they lube themself or else they would fail with only a few hours or minutes of running time.

Are you lubing the seal lips before it is installed ??.
Is the crank worn on the flywheel side where the seal lips touch & is the crank sleeve worn on the clutch side.
How about those main crank bearings, if they are worn bad that could cause the crank to be off center of the seal keeping the seal lips from sealing.


Hard to say on the trans shaft.
Normally when you torque the shaft nut, on the inner basket, it only pulls the shaft, outter basket bearing race, & transmission bearing tight to each other.
Do you have all the washer shims in the right places on the clutch pack.
May be you have the thick washer in the wrong place in the clutch & when you torque the nut its pulling the clutch gear up aginst the crankcase. Just a guess though.
Realy shouldnt be locking the shaft itself up unless somethings out of place & if it is bent, would have to be bent bad enough to see.
Pull all the clutch parts back off, click the trans into gear & rotate the trans with the output shaft & look at the clutch shaft as it rotates. May need to sit something real close to the shaft to see if its bent.

Thats as much as I know, could be something odd I've never seen before causing these problems though.
Neil
 

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Discussion Starter #3
The crank and bearings are brand new in the leaking motor. I talked to my dad last night and he asked the same thing you did. Nope, i didnt lube the seals. Stupid me.

I've pulled the clutch off about 4 times to make sure everything was in its right place. From what i know and what the clymer says, everythings in its place, correctly. Im gonna check for the bent shaft, and maybe the washer is worn down??

Anyways, thanks for the reply!
 

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Discussion Starter #4
Well, i got new seals again, lubed'em. The engine is leaking just about 1 lb. in 12 minutes. This seems acceptable to me from my little leak down experience's, but you're the man. Would this be acceptable to you? I hope so!!! ha i dont wanna deal with this engine anymore. I've taken so much time siliconing(word?) crap :lol:

On the other motor, the new billet clutch basket has some up points(^) in the grooves where the thick washer touches. The washer is basically catching on to the grooves, instead of just sliding like it should. I put a bunch of assembly lube on the washer and it still got a little tight when i torqued it, but it didnt lock up like it was before, thats how i figured it out. Im not sure what brand the basket is, but im going to file/grind down the basket a tad bit in the right spots and hopefully it's fix's the whole problem.
 

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If its no more than that then I guess it is ok. Most of my builds leak none at all.

That crank have any wear on it where the seal lips touch & you sure its leaking around the seals & not somewhere else. I've seen seals seal up even when crank bearings were bad during a leak test, but not hold once the engine was running.
Something sure is weard.
Neil
 

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Discussion Starter #6
I found out there was a tiny leak coming out of the actual air guage. I got that fixed, did another test, and the gauged moved down one line after 10 minutes, which is 1/10 of a pound. Im not getting any leak's out of the seals anymore. The crank and bearings are brand new, so i dont think there's any reason to think it will stop sealing once it's running. Where that 1/10 leaked out of, i cant find out. I've sprayed down everything, no bubbles coming from anywhere.

I filed down the little spots on the basket grooves. When tourqued, everything spins perfect now. Its kinda wierd how an imperfection of maybe a couple thousandth's can cause that.
 

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Since there hasn't been any more comments, I'll assume you figured it out. I had a case once that was leaking and could not find a leak. Pulled the counter ballancer and found out that the case was actually porus and was leaking in the curved area on the outside of the were the crank spins. It took a couple of times welding in the area of the leak but I finally got it to seal up. No problems since and I was able to easily but 6 pounds overnight and no leaks.
 
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