# How much rubber should be on the friction disk of a Toro 524 model 38040 s/n 9****?



## rechargeable (Oct 12, 2021)

My Toro 524 38040 (s/n 9*_something*_ which according to Jack's Small Engines is from 1979) doesn't move very well except in the faster forward gear. Reverse does OK but not great. My rubber friction wheel doesn't look too terrible, there's at least 1/4" of rubber on it. I don't think I can post a pic because this is my first post, however it doesn't look too different from ones that are available on ebay (example TORO 2 STAGE SNOWTHROWER FRICTION WHEEL OEM PART # 40-8170 NEW- FREE SHIPPING | eBay which is part # 40-8170).

Can anyone tell me the amount of rubber there should be on a new friction wheel and whether having 1/4" left would be the point at which it would start slipping?

ALSO, there was another post where someone asked whether it's normal having some play in the drive shaft (the shaft with the front drive pulley/plate and rear drive plate on it) and there was no answer. Mine does have a small amount of play, like 3/16" maybe... If anyone can shed light on that too I'd appreciate it.

I do intend to clean and wire wheel my front and rear drive plates which have some pitting and rust. No way am I spending hundreds to replace those though.

Thanks for any input! I do love these old machines, they are such beasts. Newer machines feel like a kid made them out of an erector set.


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## Yanmar Ronin (Jan 31, 2015)

Welcome to SBF, glad to have you aboard.

One of the Toro guys will be along soon I'm sure. Agreed cleaning/degreasing is a good first step.


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## Oneacer (Jan 3, 2011)

Any shaft , whether it be auger, impeller, drive, wheel, etc. should be firm but spinning freely with no play. Many times bushings or bearings for these shafts wear out and need to be replaced, as they are wear items, that usually need lube periodically in most cases.

Friction discs should sit just slightly away from the drive plate when not engaged in gear, 1/8 inch or so .... and either be drawn into the plate, or the plate is drawn into the disc. This engagement should be a firm bond, with no slippage or extreme deforming. Adjustments can be made to achieve this. If you don't know how that is done, then read the manual for that machine, which can be downloaded on line usually, or at least viewed , if you don't have the original in hand.

Friction discs are either one piece or some can be separated to change out just the rubber ring portion.

Plain rubber rings are under 10.00, and most one piece are around 25.00 last I looked.


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## rechargeable (Oct 12, 2021)

Thank you. I do understand the mechanisms. The play that I have is along the axis of the shaft, and not perpendicular to it. Perpendicular play is clearly a sign of bearing failure, but I don't have that. However I think I have wear on the face of the rear "bearing" (I put it in quotes because there aren't any ball bearings in it, it's basically just a cylinder with a flange). It isn't a clear cut case because if those faces were really pressed on each other then the shaft couldn't turn. I looked at it again and it's more like 1/16" of play, not 3/16"... I still have to clean up the plates and adjust the wheel and see how things work. Just wanted to know if anyone knows what's normal for this model.


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## paulm12 (May 22, 2015)

here is what mine looks like. I have noted that the upper (in this view, machine tipped) drive plate always has a bit of slop, the attachment method is not that robust. It is used for reverse gears on these machines. The pulley surface is used for forward gears. And yes, there is slop along the axis, I'm guessing the motion of the spinning pulley forces the drive disc to one side or the other of that inherent slop. 

Let me know if I can get other pics for you.


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## Oneacer (Jan 3, 2011)

@recharge,

Those "bearings" you refer to are also called bushings, and are usually brass, oil impregnated wear items, and replacing them as they wear out is common. I have also seen machines where those bushings were let to be worn beyond there life, and actual cause wearing in the hardened steel shaft / axle as well.

As I mentioned to someone in another post, many times to correct a situation, it is an accumulation of a few things together which causes things to not operate as they should. Many times you have to play detective to address those issues on that specific machine you are working on.

Sadly, most people just run there snowblowers, or any machine, until it is either broke or does not work as it should anymore. Maintenince on these machines is an unknown subject to most.


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