OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Removing nut from drive sprocket

Hi Guys,
New to this forum and am in the process of stripping down my SB 45 to effect some repairs. I've found a lot of useful information in the posts but I can't for the life of me remove the nut which secures the drive sprocket on the top shaft (Item 36 on the drive system parts list).
Is this a reverse thread or is there some other trick to removing it?
cheers,
Ron

Hi Ron,

I've just stripped my SB45 down a few days ago and the nut in question is a standard RH thread. The easiest way to remove it is with a rattle gun - if you have access to one. I would imagine it's a little tricky to hold the shaft still to crack the nut otherwise (but not impossible). Hopefully some of the other guys may be able to give you some better advice.

Cheers,
Michael

Hi Michael, that is good advice....if you haven't got access to a rattle gun, try wrapping some rag around the cutter clutch shaft and clamping with some vice-grips...or leave the primary chain on and place a soft piece of wood (eg. pine) in between the blades of the cylinder reel and the front roller to stop the rotation.....that can sometimes do the trick.

Hi Guys,
Initially I tried the rattle gun approach with the chain on but had no success, which is when I started to think that it might be a reverse thread.
Clamping the shaft with either vice grips or a pipe wrench (ouch) also failed as the force of the gun would cause the shaft to still spin. Armed with the info that it was a normal thread I ended up using a pipe wrench and socket leveraged with a very long extension bar. Had to use a bit of force but this did the trick (by this stage though I was throwing caution to the wind and was willing to let something snap if it had to).
Anyway thanks guys for your input. Lots of great information here on the forum. At this stage I'm intending to do a 'non cosmetic' overhaul but after seeing a lot of the posts am tempted to now go the extra distance.
cheers,
Ron

Glad you got it off Ron

I'm just starting to paint mine and if you end up doing the same I'd love to see some pics, it's always good to get some extra ideas and inspiration

Best of luck with your project!

Applying a Stillson wrench to the shaft close to the bearing, and a six point socket on a long breaker bar to the nut, if properly done on a soft shaft, will always either remove the nut or shear the shaft. A point of history: when Stillson invented his wrench he took it to the tool manufacturer he worked for. The manager instructed an employee to try it out. The employee returned to report that the tool worked: he easily twisted off and broke the water pipe he tested it on.

The only failures I've had with Stillsons were either on hard shafts, or using a wrench with blunt teeth. Of course, removing the teeth marks from the shaft afterwards is another matter entirely.

That is why I prefer using a piece of soft timber between the blades with the chain on, especially if your contemplating a full restoration.