OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers scott bonner diplomat

HI guys after many happy years the clutch unit has failed their is very little friction happening to drive the mower. I have searched the forum and found other members with similar problems, but they were not fully resolved, can anyone please assist with the proper removal and reinstallation of the clutch. bazzsheila@adam.com.au

Hi plumberbazz, and a warm welcome to the forum.
It's always great to have another Scott Bonnar owner on board.
Firstly, we have to ascertain which model of Diplomat you own...is it a 430 or 590. To assist us in being able to help you, can you please post a couple of pics of your machine, and the ID plate details.
Is the machine moving under its own power at all?
If it is, the drive clutch may be the culprit....however if it is not moving at all...I would suspect the plastic ring gear contained inside the rear roller assembly.
We can step you through the procedure, once we have the pics.

Thanks for helping, the mower has limited self propel and stops under cutting loads, lots of pushing to keep mowing , have attached pictures the mowers width i




s 450mm

The dimensions in width of the mower is 450mm

Hi plumberbazz, there should be an ID plate attached to the machine somewhere, that will give us the model number, which on looking at the photos I believe to be a Model 430 Diplomat.
Seeing as it has limited drive, I think that the clutch cork has worn out and needs replacing, rather than failure of the plastic ring gear in the rear roller assembly.
There is a Parts List for the SB 430in the Parts Lists and Manuals topic contained in the "Repairs and Maintenance"
forum that may come in handy for you. Access is by subscription, the "how to access guide" contained HERE

I will try and find some info on the clutch removal procedures for you...

Hi again plumberbazz, I have found a thread that goes into both rear roll and clutch removal on a Model 590 Diplomat...you may glean some knowledge from this thread, Click HERE
Hoping this helps.

Same thing happened to my Diplomat.
If you lift the rear rollers off the ground do they spin but stop when you lower it?
If so it will probably be the plastic ring gear spinning on its centre bezel under load.
You can buy a metal replacement ring gear