Export thread

I have a Kaw FH721V, 25 hp. Changed the oil recently to Shell T-5, 15w40. I had been using SAE 30 full synthetic, Cut grass for about 45 minutes and the engine sounded strange. Sounded like a bad muffler. I checked the oil and there wasn’t any on the stick. I put in about a quart to the full mark and continued cutting for about another hour. checked the oil when I finished and the oil was on the bottom of the stick. At this point, oil was running down the engine from an obvious leak somewhere in the top of the engine. I pulled the top off the engine and pulled the flywheel The upper seal was pushed up about 1/8” and was rubbing the flywheel. A shiney spot on the seal. I bought a new seal and installed it today. I won’t know if this solved the problem until I mow next week. I spent most of my time today cleaning the engine and back of mower. I was really surprised at how easy the old seal came out. I was even more surprised at how easy the new seal went in. I pushed it most of the way in with my fingers. I tapped it down with a metal rod til it was about an 1/16 below the surface.

So here’s some questions: Is it possible that I got increased oil pressure when I switched to the Rotella 15w-40. Is it possible that the increased oil pressure pushed out the seal. The mower is likely close to 20 years old and has about 1500 hours on it.

No, most likely the issue is age, and the seals harden and over time just get loose. Did one on a Kohler Twin last summer due to the same issue. And that one pushed back in with finger pressure also. I have also put Loctite 641 retainer on some seals that tend to be a loose fit to try to hold them in place But I don't think I have ever had one walk back out even being installed with finger tension.

ILENGINE said:

No, most likely the issue is age, and the seals harden and over time just get loose. Did one on a Kohler Twin last summer due to the same issue. And that one pushed back in with finger pressure also. I have also put Loctite 641 retainer on some seals that tend to be a loose fit to try to hold them in place But I don't think I have ever had one walk back out even being installed with finger tension.

Click to expand...

Thanks for quick response. im hoping it was just coincidence that it started leaking after the oil change.

another question. Any idea on the torque on the flywheel bolt. Looked to be a 12mm, grade 5. Specs with my torque wrench showed about 95 ft-lbs, so that’s what I torqued it to.

Gravelier said:

Thanks for quick response. im hoping it was just coincidence that it started leaking after the oil change.

another question. Any idea on the torque on the flywheel bolt. Looked to be a 12mm, grade 5. Specs with my torque wrench showed about 95 ft-lbs, so that’s what I torqued it to.

Click to expand...

Service manual shows flywheel bolt at 41 lb/ft