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Discussion Starter #1
Hi all,
I have a Snapper824 and I’m at a loss on this one.

I started to lose my upper gears last winter. I changed the drive wheel thinking that was the issue. It wasn’t. It was then I noticed how much movement the sheave had when the drive wheel engaged it. Almost a quarter of an inch. I replaced the bearings and it was still there. Most recently I removed it again, and inspected the shaft and the sheave for wear, excessive run out and damage. Again nothing. I shimmed it and it was solid. Now it’s doing it again.

Has anyone see this before?

Thanks,
Scott
 

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Do mean the pulley on the engine crankshaft? Don't know how that could become loose. Usually it's a light press fit and an end bolt or set screw.
 

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Sounds like he is talking about the plate that the rubber drive wheel engages on the friction drive to me, but not terribly clear . . .
 

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A sheave is actually a small cylindrical element, usually with bearings, in the center of a pulley to allow the pulley to spin freely, as such in the idler pulley. At least that is what I thought. I don't hear the term sheave much.

Are you referring to an actual solid keyed pulley on the engine shaft?

Maybe a photo would explain better.
 

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I agree with tadawson that the "sheave" referred to is the drive plate in the transmission. T4rscott states that the "sheave" moved 1/4 inch when engaged by the friction wheel. It is not totally clear from the description but as described the friction wheel moves and the drive plate is stationary. Some transmission designs do use the side of the lower drive pulley as the drive plate. T4rscott states that he inspected the "sheave" hardware for wear, found nothing, "shimmed it" (unexplained), but the problem reoccurred. In any case, the problem should be able to be identified by inspection of the thrust bearing for the drive plate. Something in the thrust bearing or its mounting hardware must be worn or loose to allow 1/4 inch of movement.

A sheave is a wheel with a groove (for a belt, rope or cable). Pulley is often used interchangeably with sheave. But, a sheave is a type of pulley but a pulley (e.g., flat/crowned) is not necessarily a sheave. The use of the term varies with geography and industry. It is often used by industrial suppliers that stock separate sheaves with split tapered bushings to reduce inventory requirements.
 

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Discussion Starter #6
It is the large pulley/ wheel that the rubber wheel presses against when the drive is engaged.

Snapper refers to it as a sheave. Sorry for any confusion.

To recap, the large wheel moves forward about 1/4” when the drive is engaged. It causes the rubber drive wheel to slip in the two highest gears. I replaced the bearings and then shimmed it so the snap ring was snugged up against the large pulley.

Again, sorry for any confusion. I hope this clears it up?

Scott
 

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If I remember right those old Snappers drive plates run off the engine by belt, but spins on the impeller shaft, right? Like if you split the machine bucket from the transmission, the drive sheave stays with the auger bucket. I would guess the entire impeller shaft is moving the 1/4", or the auger/impeller bearing lost it's set screw clamping force. There's 3 bearings in line there I think, two in the drive sheave and the bigger one with set screws at the bucket for the impeller shaft.
 
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