Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Toro's web site points out that they do not employ shearpins  to protect the gear train . What serves this function in their two stage machines?

Marc

The newest Toro's employ a Hardened drivetrain system, that when a substantial object is encountered, the machine just stops. You then remove the object, and continue on. Some have reported it worked as described when encountering frozen newspapers.

I still prefer a shear pin. A cheap item that has worked for many decades.

The aluminum gearbox is pretty big when compared to some other brands, so it is a heavy duty design.  I just wonder if you do run head on into a newspaper and the machine stops, as its designed to, how the heck do you unjam it?   At least if you had shearpins and one or both broke, the augers would freewheel allowing you to remove the obstruction.  Since I don't want to deal with the situation at all, I make it a point to walk my property prior to snow falling.  I admit, I do hold my breath while doing the EOD.  I'm sure many would have some stories as to what those snow plows drag along in the streets. It's a situation you have no control over and a crap-shoot to say the least.

I cant find the post, but it took over a Half hour to remove that newspaper, it made it to the impeller.  A small TORCh might have sped up the process.

Ive encountered a Brick, and a few other small items that poped shear pins, with no permanent damage.

I can only imagine somebody with a Gravel driveway, Having the machine stop dead several yimes from Gravel ingestion, and what repeated abuse could cause. Something must eventually give.

Those gears must really be something to take that kind of strain. Wouldn't the shock be transmitted all the way back through the auger drive to the engine? You would think one of the belts would slip.

Marc 

   

mml4 wrote:

From the tip of the first Auger, all the way to the Piston. Yes, some belt slippage MUST be factored in.  Id love to run the numbers to figure the load of a BIG 11 HP engine at WOT, coming to a scretching hault when a ROCK jams the impeller.

When somebody came up with the idea of no SHEAR pins, some Engineers must have had COLD SWEATS.

If I only had the Toro manual.

There should be a KEY ( woodruff, hex, etc) for the Impeller mount, also one for each pulley on a shaft, Dont forget the keyway on the Flywheel. Id guess at least 4-5 keyways in the system. 

An if all that don't give.  It's oh well I think I spun a rod. then its (new rod, machine c-shaft journal down maybe 2 thou under new babbot inserts 2thou  over ((maybe even 1 thou as it is usually 1 thou per inch thickness of the diameter))  Too expensive unless you get machining for free so it's buy a shortblock.

Ben07

The ones I have seen still have a bolts that can be removed to clear a jam. I would not think there would be anything to stop someone from putting correctly sized shear bolts in place of the regular bolts. Some of those old drum augers never used shear bolts that I could see.

Mountain,

Yes, I meant woodruff key.  I thought that when the auger strikes something causing the engines to stop suddenly from operating RPM, sometimes the woodruff key can break on the flywheel of the engine.  I didn't actually mean on other parts of the snowblower.  When this happens, I thought the timing on the engine gets fouled up and it really won't run correctly or not at all.

Rob, thanks for grabbing those exploded views.