For the most part, I've been satisfied with the performance of the 47 Snowblower (although I liked my previous 46 Snow Thrower more--but that's a different tale). However, in wet/slushy snow, it would barely discharge out of the base of the chute, just on to the top of the auger housing. There were a number of posts last season about changing out the plastic impeller for the steel (AM109105). They reported a significant improvement with wet, slushy, snow as a result of that.
On another forum, I read about where a fellow had decided to upgrade from the plastic to the steel impeller and the issues he encountered removing the plastic impeller from the gear box input shaft. The fact that the plastic impeller inner bushing had virtually welded itself to input shaft, with corrosion, gave me pause to ponder the damage that would be done if the snowblower ingested foreign matter and the impeller sheer bolt would not break, due to this. This issue was the final push that motivated my decision to change out the impeller.
In the above referenced thread, FTWingRiders also added the "flapper" mod to the impeller as well as changing out the gearbox drive sprocket to a 36 tooth sprocket. I decided to follow suite. I went with a heavier, thicker, flapper material as they would be less likely to deflect, opening the gap between the flapper end and the impeller housing, maintaining blower efficiency. I found a reasonably priced kit from Snow Blower Impeller Blade Modification Kit
The kit instructions called for drilling/mounting the flappers through the chute opening. This would have been difficult, at best. Moreover, the front attaching bolt hole is obstructed by the impeller blade brace, welded to the backside. As such, the supplied nut could not be utilized to secure this bolt. As expected, the gearbox input shaft was not perfectly centered in the impeller housing and/or the housing was not perfectly round. I partially re-assembled the auger/gearbox, with the steel impeller on the input shaft. I then positioned each blade where the gap was minimal, held a flapper on the blade and marked out the mounting holes, on the blade, with a china marker. Once the holes were marked, I removed the impeller, secured in a vise, and drilled the rear holes to pass a 5/16 bolt. The front holes, that are obstructed by the blade braces, I drilled and tapped to accept the 5/16 bolts. When assembling, I applied blue Loctite to those bolts being threaded into to the tapped holes.
As jgayman referred to and dave_r suggested, I drilled and tapped the shaft bore of the impeller, while secured in the vise, to accept a grease zerk. In this manner, the impeller will be greased annually, like the auger, to prevent it from corroding tight to the rotating shaft and allowing its sheer pin to break in the event of foreign matter ingestion.
While I had the auger/gearbox removed from the housing, I removed the aluminum impeller drive arm and applied anti-seize compound to its shaft mounting area. This was in the hope it would prevent/minimize it from corroding. Aluminum does not react well with steel.
As FTWingRiders did, I replace the gearbox drive sprocket with a 36 tooth sprocket. (Be sure to select the sprocket with a 1" shaft bore.) This was not so much to gain some extra speed, but rather address the excessive runout of the OEM sprocket in which the hub is poorly centered when welded to the sprocket. I'm confident the 1025R's diesel can easily handle the extra load caused by the smaller diameter sprocket. Again, I applied anti-seize to the sprocket mounting area of the input shaft as well as blue Loctite to the sprocket setscrews. The sprocket drive chain will also require shortening, as a result of the smaller sprocket. The OEM chain is assembled without a masterlink, so one will be required after shortening.
My other issue with this 47 Snowblower is even with the side shoes set flush with the scraper bar, it did poorly at cleaning snow off the concrete---much more so than my previous 46 Snow Thrower. I came across another thread where baler belt was sandwiched between two scraper bars or a length of flat steel. So I decided to incorporate this improvement while I had the snow blower up on the horses. Rather than utilizing flat steel to sandwich the baler belt, I opted for a second scraper bar. The only baler belt I could locate was 4" in width. Reducing the width while maintaining a straight edge would be difficult. Installing it full width, with the flat steel, would likely result in it rolling over on itself. Sandwiching it between two scraper bars results in approximately 9/16" of baler belt protruding from each side.
I began by centering and sandwiching the baler belt between the scraper bars, secured with vise grips. I pre-drilled the belt in this configuration.
Of course, this required longer attaching bolts. The OEM bolts are metric. However, 5/16 SAE bolts are near identical dimensions and much easier to source as well as less expensive than metric carriage bolts. I utilized 5/16 x 1-1/4" carriage bolts and 5/16 serrated flange nuts.
I sourced the scraper bars from Heavy Hitch. They were $79.00 compared to $74.23 for a M135649 from greenfarmparts.com. The Heavy Hitch scraper bar includes the attaching bolts & nuts and they are stainless to boot. So that, by itself, more than offsets the price difference of the product. Green Farm Parts flat rate, or if the free shipping promo is running, is much less than Heavy Hitch's UPS Ground rates. However, the Heavy Hitch scraper bar appears to be a heavier gauge and fabricated from AR400 steel. In my opinion, the Heavy Hitch scraper bar is a better value.
Well, the proof of how well these mods perform will be in the pudding---correction, snow.