Dumping oil from the bottom seal

arch252

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17hp twin cylinder liquid cooled Kawi on a JD LX279. Got it out to start the season and used it about 15 minutes and parked it and saw oil dumping from the bottom. Raised it up and removed the PTO and pulley and the bottom seal looked good but that's obviously where the oil came from.

I replaced the seal and ran it about 15 minutes again and parked it and it dumped the oil again. I figured I had just gotten sloppy when replacing the new seal. Raised it up and again I could tell the oil came from the seal but it looked good.

I got another seal. Removed the old one. Checked the shaft very carefully. No burrs, marks or rust, it was very clean. I carefully installed the new seal. Ran it for about 1 minute with the PTO and pulley off, no drips at all. Two days later I got the mower out and ran it again and about the 15 minute mark it started dumping the oil again.

There was an old thread here with someone who had the same exact issue but there was never any cause identified.

I'm using Rotella synthetic, I forget what weight. Mower runs good otherwise, no smoke, no knocking.

There is no oil dripping from the seal. It's not until the mower has been running about 15 minutes and then it dumps the oil, a good steady stream.

Does anyone have any idea what's going on here?
 

Luffydog

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Do a leak down test you prob find your problem lies in the top end. Like blow by from the rings or worn cyclinder or blown head gaskets. Also if it has a valve cover with a breather valve and the hose. Check the hose make sure it is good. But do the leak down test it should lead you to the prob.
 

Luffydog

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Engine numbers would be a good thing to better help out with the prob.
 

cpurvis

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What did the original seal look like? Could you see any damaged areas on it?

How about the seals you installed? Could you see any damaged areas on them?

If not, as suggested above, you may have a problem with crankcase ventilation.
 

bertsmobile1

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17hp twin cylinder liquid cooled Kawi on a JD LX279. Got it out to start the season and used it about 15 minutes and parked it and saw oil dumping from the bottom. Raised it up and removed the PTO and pulley and the bottom seal looked good but that's obviously where the oil came from.

I replaced the seal and ran it about 15 minutes again and parked it and it dumped the oil again. I figured I had just gotten sloppy when replacing the new seal. Raised it up and again I could tell the oil came from the seal but it looked good.

I got another seal. Removed the old one. Checked the shaft very carefully. No burrs, marks or rust, it was very clean. I carefully installed the new seal. Ran it for about 1 minute with the PTO and pulley off, no drips at all. Two days later I got the mower out and ran it again and about the 15 minute mark it started dumping the oil again.

There was an old thread here with someone who had the same exact issue but there was never any cause identified.

I'm using Rotella synthetic, I forget what weight. Mower runs good otherwise, no smoke, no knocking.

There is no oil dripping from the seal. It's not until the mower has been running about 15 minutes and then it dumps the oil, a good steady stream.

Does anyone have any idea what's going on here?

Clock the crankshaft
a bent crank will do exactly what is happening to you
 

Luffydog

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I also thought about it being bent as well. I have heard of people putting two seals in to stop the leak.
 

cpurvis

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I also thought about it being bent as well. I have heard of people putting two seals in to stop the leak.



Got it out to start the season and used it about 15 minutes and parked it and saw oil dumping from the bottom.
That statement seems to imply that the mower was not leaking oil when it was put away for the season. One has to wonder when and how the crank may have gotten bent while it was in storage.
 

Luffydog

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Some of those r very famous for melting the valve covers and leaking as well.
 

arch252

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The engine is a FD501V. The original seal looked great. Both replacement seals looked fine when I put then in. It ran great all summer, never had any leaks. Nothing has been done that would have caused a bent crank, hasn't hit anything. It would have to be an internal issue.

The guy in the previous thread said he had reason to belive his crank was somehow lifting up above the seal, his problem also was occurring after 15 minutes of operation. I think he did an engine swap so never identified the cause of his trouble.

I'm at a loss and I'm not ready to pull the engine and split it open until I have somewhat of an idea of what the cause might be.
 

bertsmobile1

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The engine is a FD501V. The original seal looked great. Both replacement seals looked fine when I put then in. It ran great all summer, never had any leaks. Nothing has been done that would have caused a bent crank, hasn't hit anything. It would have to be an internal issue.

The guy in the previous thread said he had reason to belive his crank was somehow lifting up above the seal, his problem also was occurring after 15 minutes of operation. I think he did an engine swap so never identified the cause of his trouble.

I'm at a loss and I'm not ready to pull the engine and split it open until I have somewhat of an idea of what the cause might be.

Grab the flywheel and try to lift it up.
There should be 0.010" to 0.040" up and down movement.
Try to move it left right
There should be no movement.

When engines are run low oil it can chew out the bottom seat for the crank.
 
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