OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Scott Bonnar 45 Thrust Bearing

Hi all,

I’ve finally got my 17” model 45 in pieces for new rails and a freshen up. I wasn’t going to bother changing the thrust bearing in the clutch but it seems pretty dry and a little rumbly. I squirted some TAC-2 lube in it and it has improved heaps. I know people will say to change it while you can - However I would like to know what other peoples experiences are with these are. They seem pretty pricey from what I can find.

Cheers,

John

Hi John,

Honestly replacing these bearings is rather over rated.

A good solvent clean out and forcing a small amount of grease in to it will have it go for another 20 years. This bearing only has load applied when the clutch is engaged and that time is generally minimal and as such wear and tare is also minimal.

A freshen up is all I've ever found that they require............unless they've suffered major water exposure.

Spending ridiculous amounts of cash on these machines is what this cottage industry is relying on.

Cheers,
BB.

Hi BB,

Thanks for getting back to me. I figured pressing the bearing out to grease it would ruin it, so left it in there and put a fair bit of chain lube in there. Is there a way to press it out without damaging it so it can grease it?

Cheers,

John

jds303,

I've got a new self aligning bearing kicking around, but I never put it in. Yet, anyway.

Mine was fine, but I decided to clean out the little oil hole in the bearing housing without removing the bearing. In a bright spark moment, I got the air gun and forced a whole heap of crud into the bearing proper.

Crunch, crunch, crunch...

Flushed it out with copious amounts of degreaser and more air. Fixed the stuff up and now I'm just oiling it every second use, or so.

It's smooth and the machine is cutting very well. If it ever goes I've got the spare but I'm not in any hurry to pop it on.

Hope that helps.

Ahhhh, I misread your post. Sorry!

The only reason I replaced my clutch bearing was because I left the old one in there when I got the clutch sand blasted and powder coated as a sacrificial bearing.

Easiest ways to remove that bearing from the clutch half is either to get two blocks of wood and knock the clutch half onto the wood to let the bearing drop out between the blocks, or get a little punch and gently tap the bearing out from the other side. If you use the second method, be careful not to deform the housing otherwise you may end up needing a new bearing when there was no need for one.

Hi MS,

You'll be bangin' away all day trying to get that bearing out if using that two wooden blocks method.

Generally you shouldn't apply shock or undue pressure on the centre race when wanting to reuse a bearing, but in the case of this type of bearing you have no choice but the design of this unit has all the pressure when the clutch is engaged on the curved section of the outer race.

Normally the correct tool to use is a spreadable 3 jaw head that slides inside the centre hole and has a slide hammer on it and thus you would then just evenly pull / knock it out.

If you slightly distort the flat side of that bearing one can skilfully tap it back into shape as that's not a running surface. To do that use the appropriate size 1/2 inch drive sockets that will come in contact all around the bearing surface and then use a soft blow plastic assembly hammer and progressively knock it back into shape how it should be.

As such over 40 odd years of working on these machines I've never had to replace one of these long life bearings with a new one.

Cheers,
BB.

Hi guys,

Thanks for the responses. I’ll just lube it up as best I can and spend that money on a new self aligning bearing in place of the sealed unit on the clutch shaft.

Cheers,

John

Hi John,

Be careful who you buy the self aligning bearing from as there are quite a few better options around opposed to the highball eBay sellers.

You shouldn't pay anymore than $20 for that one.

Cheers,
BB.

Hi BB,

There are a few bearing distributors in the suburb I work in - I’m sure they’ll be a more reasonable price. Might have to get the clutch shaft seal off eBay though, unless they have them in the store here.

Cheers,

John

Hi John,

That you'll have to get off Cameron at OPE-Parts on the ol' bay.

Cheers,
BB.

Hi all,

I just bought an NSK self aligning bearing (1202) for $11 locally. Now, it is oiled, should I leave it as is and oil it periodically, or grease it?

Cheers,

John

Hi John,

Honestly I'd just pack it full of good bearing grease, something like Castrol HTB etc.

Cheers,
BB.

Cheers BB, will do. Thanks for all the input over something as simple as a bearing.