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

   This summer an 824 came up for $100 because it was broken and I bought it as a fixup .  The unit would not go move forward because the drive sprocket teeth on the hex shaft were touching the teeth of of another gear on another shaft.  

   The transfer setup power is this.  The hex shaft carries the friction disk and a small gear which drive a chain.  The friction drive plate is moved forward by the hand control.  It presses against the friction disk on the hex shaft, rotates the hex shaft and turns a small gear and chain.  The chain drives a large gear on another shaft which through other gearing turns the wheels.

   It turned out that the hex shaft support bearing had worn and the shaft so loose the drive gear on that drive shaft meshed with the teeth of the large drive gear on the traction drive shaft and the chewed the teeth of the large gear.  The warn flange bearing caused the traction drive problems because it was worn, enlarged enough to create slop.

   The large gear, drive chain and both flange support bearings were replaced.  After light use this winter the snowblower was not moving to fast in forward and slipping in reverse.  It turns out the flange bearing is worn again and the hex shaft so loose it does not keep the friction disk drive wheel in place with good pressure when the drive plate goes up to drive it. 

   The rig will go forward and barely backward but in a another week of use the flange bearing will be warn enough it won't move at all.  The shaft will be so sloppy on the flange bearing it will not provide support when the drive plate is pressed into the friction disk.

  The flange bearing is not a roller bearing.  The internal part the bearing is called powdered metal something.  It not solid metal or a roller bearing.  It is powdered metal bonded with something to form a round internal section something like half of an egg with a hole for the shaft end to ride on.  The hex shaft the friction disk rides on is the flange bearing of powdered metal.  The egg shape powdered metal part does not rotate with the shaft.  It stays in place and the shaft rotates inside the powdered metal part of the bearing.  The hex shaft fits into the flange bearing with a loose fit so just rides on the powdered metal part of the flange bearing.  This does not seem like a great arrangement to me but the Toro repair place says they do not see that many flange bearing repairs.  They say my quick wearout is very odd.

   The powdered metal part inside wearing out quickly may be my fault by using the old hex shaft and not buying a new one.  It may have been rough and chewed right through the replacement flange bearing powdered metal again.  I am not sure of the condition of the end of the shaft when I replaced the flange bearing.  It's now very rough and will eat right through another replacement bearing.

   Here is the question.
   I would like to replace the powdered metal flange bearing with a flanged roller bearing.  I don't know about bearings and looking for advice if this is a good ideal or other alternatives.  A few net searches show some flange bearings with set screws to keep the shaft locked inplace.  The original design seems hoaky to me.  The shaft supported in powdered metal does not seem so great and if I replace both again I think the powdered metal will just wear again.  I'm suprised Toro uses such a crummy setup which I would think would wear out quicky but the Toro guy claims he does not have a big call for those parts. Any suggestions?

The pictures show my bearing and possible replacement bearings.

I really haven't the slightest idea of how to repond other than to say it appears that your diagnosis is well thought out . If you go with the roller bearing set up I think you need to get one that is sealed.The environment that this assembly is functioning in is often contaminated with debris from the rubber drive disk wearing and an unsealed bearing which is greased will absorb that material.

 If you go with the new set up are you going to replace the shaft as well?

Marc

Marc,
  Two pictures now show up of what might be possible bearing replacements. The picture of my worn bearing and shaft end does not show up for some reason.

  A sealed bearing might be required given the environment as you mentioned.  Temperature is not a problem.  MTD uses them in there auger supports. 

  The shaft will have to be replaced.  The end that went into the bearing is all chewed up.  It would have to be worked smooth so probably just as well to get a new on which is $33.

  The original bearing is powdered metal and after snooping around the net it seems they can be made pretty hard and possibly this one was self lubricating.  It might be why Toro chose that type.  Powdered bearings are 10 percent less expensive than roller bearings.  They can be durable and impregnated with lubricant as they are porous.  When the bearing is used lubricant goes to the surface to lubricate the rotating shaft due to heat.  When cooled the lubricant retreats back into the powdered material.  

   Maybe I can get some idea of use Monday when the bearing manf's are back to work and the tech people available.  They want to sell a box car of bearings and I'm looking for two so they probably wont bend over backwards helping me.
trouts2