Rotary mower gearbox input seal. How often gear oil change?

18 Feb.,2024

 

CobyRupert said:

My manual says 鉄torage: At end of your cutting season: 1. Drain and change the oil in the gearbox.
I never have.

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Me either.

But, look on the bright side: If the seal is leaking and you keep adding oil, that's basically changing it, right? Just kidding.

I would suggest, instead of changing the seal right now, top it off with 85W-140 and finish the season. Change it this winter, after you're done mowing.

To change the seal, it's pretty straightforward. Remove the 8 bolts that hold the front cover (faceplate) on. Remove the front cover. You may need to use a putty knife, sharp screwdriver, etc. to get it started. The input shaft will stay put, just slide the cover over it. The seal should come out of the back side of the cover. Remove the old seal. Install the new seal. It needs to be pressed in, or use a seal driver of the appropriate size. (a 3/4" drive socket, the same diameter as the seal, will do) AFTER you clean and de-burr the input shaft, re-install the front cover. If you don't remove any burrs or rust from the input shaft, you may damage the new seal. I like to use emery cloth to shine it up. I don't see a gasket or O-ring on the front cover. It will need to be sealed to the gearbox. If there's nothing there when you remove it, I would use Permatex #2. You could use RTV (silicone), but it has to be really clean, and then nothing else will ever seal that joint again. Re-install the driveline and guards. Fill the gearbox with oil.

Me either.But, look on the bright side: If the seal is leaking and you keep adding oil, that's basically changing it, right?Just kidding.I would suggest, instead of changing the seal right now, top it off with 85W-140 and finish the season. Change it this winter, after you're done mowing.To change the seal, it's pretty straightforward. Remove the 8 bolts that hold the front cover (faceplate) on. Remove the front cover. You may need to use a putty knife, sharp screwdriver, etc. to get it started. The input shaft will stay put, just slide the cover over it. The seal should come out of the back side of the cover. Remove the old seal. Install the new seal. It needs to be pressed in, or use a seal driver of the appropriate size. (a 3/4" drive socket, the same diameter as the seal, will do) AFTER you clean and de-burr the input shaft, re-install the front cover. If you don't remove any burrs or rust from the input shaft, you may damage the new seal. I like to use emery cloth to shine it up. I don't see a gasket or O-ring on the front cover. It will need to be sealed to the gearbox. If there's nothing there when you remove it, I would use Permatex #2. You could use RTV (silicone), but it has to be really clean, and then nothing else will ever seal that joint again. Re-install the driveline and guards. Fill the gearbox with oil.