Mower gearbox seal help

upnorthwi · Jun 18, 2016

I have a Sitrex SM180 finish mower. The one belt came apart and part of the cords wrapped around the gearbox shaft between the housing and the pulley.....and oil was leaking out. I'm not sure if it was from pressure on the seal or the seal is damaged. I removed the gearbox and all the pieces of belt wrapped around it. The seal looks to be intact but scuffed up.

My problem is there is a big internal circlip with no holes for a removal tool, that I need to get out to replace the seal.

How do you remove these rings?

Are they replaceable? I need the seal and possibly the ring if I have to some how cut it out.

Any help would be appreciated.

Texasmark1 · Jun 18, 2016

Why not take something like a 4" cutoff wheel, or grinder if you don't have that, and grind a vertical slit in the casting holding the clop, near the end of the clip just deep enough to see the clip. Then drive a sharp pointed punch in the slit between the casting and the clip till you get enough of the end of the clip up so that you can work something under it and prise it out.

upnorthwi · Jun 19, 2016

That's an idea I'll probably try. I can't figure out how to remove it otherwise. The shaft is in the way to really try and work a tool at the ends...which there isn't much of an end. I can't find replacement
rings so I need to try to save it. I can't find an inexpensive gearbox that matches to throw on. I'm half tempted to just put some oil in it while it's on the bench and see how bad the leak is. Maybe the corn
head grease would be an answer.

It's a great mower, first problem in 11 years, but foreign equipment is a pain when it comes to parts.

Texasmark1 · Jun 19, 2016

(quoted from post at 12:37:08 06/19/16) That's an idea I'll probably try. I can't figure out how to remove it otherwise. The shaft is in the way to really try and work a tool at the ends...which there isn't much of an end. I can't find replacement
rings so I need to try to save it. I can't find an inexpensive gearbox that matches to throw on. I'm half tempted to just put some oil in it while it's on the bench and see how bad the leak is. Maybe the corn
head grease would be an answer.

It's a great mower, first problem in 11 years, but foreign equipment is a pain when it comes to parts.

The grinder can be angled so that it doesn't contact the shaft. I didn't have access to Cornhead but used Lubriplate 105 in similar situations. It's a popular engine rebuilding product from Lubriplate. Viscosity is somewhere between 90w and #2 grease so you still get mobility, just not as thin.

Other thing is you need to have a vented fill screw to prevent pressure buildup when mowing and oil gets hot and expands. That in itself helps a lot.....noticed that OEMs are finally installing them during production. Auto parts stores carry them.

upnorthwi · Jun 19, 2016

Thank you for the tips!

Mower gearbox seal help

upnorthwi

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Texasmark1

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upnorthwi

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Texasmark1

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upnorthwi

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