Z121S Lawn Mover bolt for Blade broke off in the Final Drive

[tfowler9]

Has anyone have this happen? Cutting my grass and heard a loud bang. Thought I might have hit a sprinkler head. Nope, the bolt snapped and the blade,,,luckily drove into the ground.
Not sure on how to fix. Try to drill out the bolt or replace the Final drive. In either case how do I prevent the final drive from spinning while I am trying to remove?

Thanks, any suggestions would be very welcome. Tom

 

[StarTech]

If you referring to bolt holding the blade on, Yes had a Hustler Zuper Z to shear one. When I found the remains I found that someone had replace the bolt with with a low frade one.

blade bolt is a M12-1.25 x 30mm and should be a grade 10.9 and not be a 8.8 or less.

 

[ILENGINE]

You may be able to take a small punch and catch the edge of the broken bolt and with small taps spin the broken bolt out. Most of the time when a bolt breaks off pending corrosion or other factors you can about spin it out with your fingers.

 

[mikekir]

Good luck. There are screw extractors that have a left hand twist to them. You drill a hole, and insert the extractor in a left hand direction. To find strong bolts, look at the head. The more marks on them, the stronger they are. The really good ones have a mark that makes a hexagon or such.

 

[StarTech]

To find strong bolts, look at the head. The more marks on them, the stronger they are. The really good ones have a mark that makes a hexagon or such.

Only SAE bolts have those marks, metric uses numbers. Higher the number stronger the bolt.

 

[hlw49]

like ILENGINE said most of the time the bolt is not tight when they break off and turn out easily. You can try a left hand drill bit and if it hangs in the bolt it will spin it right out.

 

[tfowler9]

Thanks guys for all ypuir replay! Hope you're right on the ease of extraction. Tom

 

[tfowler9]

Thanks guys for all ypuir replay! Hope you're right on the ease of extraction. Tom

Was able to remove the broken bolt and yes it was easier than expected! Another question. One of the bolts on another blade was very tight getting out...unlike the other two. Maybe a slight miss thread when installing. I would like to clean it up with a tap. Anyone know the size tap I will need?

Tom

 

[StarTech]

Have no earthly idea what you need for a M12-1.25 blade bolt.

 

[Hammermechanicman]

Have no earthly idea what you need for a M12-1.25 blade bolt.

The fun part is M12 comes in 3 flavors. 1.25 1.5 and 1.75 pitch threads. Not sure the need for 3 different thread pitches but i have taps and dies for all 3 now because everybody has to be different.