Snowblower I Shrunk my Snowblower

[herringchoker]

I narrowed my rear mount snowblower from 74 in. to 62 in. wide.

Why would a sane person do that?

My blower is a no-name (that bears an uncanny resemblance to a Lucknow) that I purchased new from a short line dealer almost 25 years ago. It was originally mounted on a larger gear drive tractor, but when I replaced that with the smaller Kubota B7800 HST almost 12 years ago, I thought I would try it on the new tractor. Danged if that little tractor didn't handle the big blower like a champ! The only problem was that the blower is 20 in. wider than my FEL bucket, I use both for snow removal, and I've had a few close calls nearly side-swiping things with the blower when using the FEL. So for the last 12 years I've been contemplating a narrower blower.

Well, last winter I was forced to do something when the impeller shaft seal started leaking lube and letting water into the gearbox. I sucked the contaminated gear oil out of the gearbox and replaced with good lube a couple of times to finish off the winter. I was scared by the price of new 60 in. to 64 in. snowblowers ($2700 to $3300 including hydraulic swing, but not a powered deflector), and none that I looked at had gearboxes as heavy as my old no-name. And besides, I'm retired and I need a good challenge to keep my mind from rotting! Or maybe I'm not sane!

I don't have any exotic new tools to work with: 1971 Miller 225 AC stick welder, new Lincoln 140A wire feed welder, three 4-1/2 in. angle grinders (one each for cutting, grinding and brushing), 8 in. bench grinder, 14 in. cutoff saw, 7-1/4 in. circular saw that uses abrasive wheels worn down on the 14 in. saw, an ancient oxy-acetylene outfit and miscellaneous hand tools. I did most of the cutting with the angle grinder and most of the welding with the stick welder, except the 10 ga. metal housing was done with the wire feed welder (which I was just learning to use).

The first step was to remove the auger. This pained me a little because I had replaced the auger bearings a few years ago.

 

[herringchoker]

REMOVING THE IMPELLER

No surprise, this turned out to be the worst part of the whole job, the fan being rusted solidly onto the shaft after all those years in the wet and salt. I tried soaking it for days with penetrating oil, I tried heat, I tried a 25 ton mechanical jack with encouragement from a 15 lb. post maul, all with no success. In fact, the jack and maul only succeeded in breaking one of the chain slots I welded onto the fan, which was made from a piece of 3/8 in. thick Kenworth truck spring. So, I took a deep breath and used the torch and cold chisel to split the fan hub.

These photos show the jack setup, the broken chain slot, the split hub and (finally) the removed impeller.

 

[herringchoker]

REBUILDING THE IMPELLER

Since I had to destroy the impeller hub to get the impeller off the shaft, I had to replace the hub. The shaft is 1-3/8 in. diameter with a 3/8 in. keyway. (I notice that the new snowblowers in the 5 ft. to 6 ft. width class have 1-1/4 in. impeller shafts one reason to keep the old.) The fan hub is actually an off-the-shelf keyed coupler, with one problem for my unit: the standard keyway for a 1-3/8 in. shaft is 5/16 in., where mine has a 3/8 in. keyway. I bought the new hub from a local machine shop and had them broach it out from a 5/16 in. to a 3/8 in. keyway.

I had to cut the blade braces off the fan and weld them back in again in order to get at the hub area with an angle grinder to clean up the mess from splitting and removing the hub. I then welded the new hub into place, taking special care to ensure it was at right angles to the blades and truly centered. While I was at it, I drilled 2 holes near the tip of each blade for possible future installation of a rubber paddle-type impeller kit.

Next, I had to make sure the fan was centered and balanced. I set up the gearbox on the bench and turned the fan, measuring blade reach variation using a square and I rigged up an electric drill to spin the fan on the gearbox to check balance. I found the fan to be centered within about 3/32 in., which was about the same as I had measured before I removed it from the blower. However when spun, the fan had a slight but noticeable vibration. The next step was to set up a static balancing stand using two ball bearings in the hub turning on a 9/16 in. shaft levelled between two saw horses. The fan showed a definite imbalance, so I placed small magnets by trial and error on two adjacent fan blades to obtain balance. I weighed the magnets on a small weight-watchers scale, then welded on slightly heavier pieces of 3/8 in. keystock to replace the magnets and then ground them down to obtain final balance. I added a total of about 4 oz. to the 2 blades.

 

[herringchoker]

SHORTENING THE AUGER

I shortened the auger by cutting 12 in. out of the centre, cutting the paddles and sections of flight away first. The auger shaft is 3 in. I.D. Pipe. Since standard pipes don't fit snugly inside each other, I welded strips of 1 in. x 1/4 in. flat bar onto four sides of a 12 in. section of smaller pipe and ground them down so the smaller pipe fit snugly inside the auger shaft. I then used two pieces of angle clamped to the shaft to line up the two halves and welded them back together, ensuring they were aligned properly so the paddles and flights would be correct. I welded new paddles and shortened flight sections back on and then welded 3 in. pieces of 1 in.x1/4 in. flat bar as reinforcement at 90* intervals around the circumference of the butt weld on the shaft. I later found (when I mounted the auger into the narrowed blower housing) the auger was out of round (bent shaft at the splice), so I had to cut my welds and and tweak the shaft alignment with a jack and then re-weld. I used a dial micrometer to make sure I had it right the second time.

 

[herringchoker]

SHORTENING THE CHAINSHAFT

The 1-1/4 in. driveshaft for the auger chain also contains the shear pin. Since the sprocket / shear pin plate assembly was seized solidly to the shaft, I had to cut the sprocket to get it off the shaft. A new sprocket and the cleaned-up shear pin plate were installed with liberal amounts of anti-sieze compound. I cut 6 in. out of the shaft itself and welded it back together using a standard 1-1/4 in. coupler for alignment and strength.

 

[herringchoker]

REPAIRING THE FRAME

The snowblower was suffering from over 20 years of sometimes hard use. The left frame rail and the 3-point hitch mounting were bent from numerous curb encounters with the previous larger tractor.

I removed the bent frame rail and fabricated a new one from 3 in.x3 in.x3/16 in. angle and 3 in.x3/16 in. flat bar and welded it in place. Using heat and brute force, I was able to tweak the 3-point hitch back into shape. I also installed new lift pins.

I also took the opportunity to double the width of the skid shoes, using 3 in.x3/8 in. flat bar.

 

[herringchoker]

NARROWING THE HOUSING

This was the easiest part of the whole job. I cut 6 in. out of each side of the 10 ga. housing using cutting wheels on a 4-1/2 in. angle grinder, supporting the assembly on a screw jack and jack stands. I clamped angles to the housing to align the side sections with the main body and welded everything back together using the wire feed welder.

 

[herringchoker]

REPLACING THE HOUSING FLOOR

The floor of the housing was suffering from serious rusting, so I removed the wear edge and cut away the rusted floor. I then welded in new angle (from my scrap pile) for the floor (so the new floor would be rigidly fastened to the back wall) and spot welded the wear edge back on. I drilled two 3/8 in. drain holes in the new floor( I had done the same years ago on the old floor the drum always had a1/2 in. drain hole straight from the factory).

 

[herringchoker]

ACCESS TO SHEAR PIN

Something I found annoying about the snowblower was that the shear pin had to be accessed from below and there was little room to swing a pipe wrench to realign the bolt holes or to get a wrench on the shear bolt once a pin had sheared. So when I put the housing back together, I welded in a small angle for rigidity and replaced the original welded-in plate with a removable plate. The shear pin can now be accessed from above by removing two bolts, and there's room to swing a pipe wrench on the chainshaft. The photos show the original setup, the access plate and how it is installed (no bolt holes yet in the pic).

 

[herringchoker]

THE FINAL PRODUCT

I disassembled the gearbox, replaced the seals on all three shafts, reassembled, added 80W90 GL-4 to the proper level, put everything back together again (including new bearings on the auger and chainshaft), applied Plasti-Kote Rust Converter, painted everything ugly orange urethane enamel (I had left over from when I had trucks contracted to a company which was fond of that colour), applied reflective tape, mounted it , spun it up and....everything works! I know my workmanship doesn't measure up with others on here, but I'm satisfied.

All told, I spent $407.23 on parts, not including 24 4-1/2 in. cutoff wheels, 5 grinding wheels, 50% of a 14 in. cutoff wheel, a good 5 pounds of 6011 and 6013 welding rods, about $20 of electricity and I don't know how much penetrating oil, anti-sieze, flux-core welding wire, oxygen and acetylene. I didn't keep track of my time, but I'm guessing about 40 to 50 hours well spent.

I've since used it to clean up after four small snowfalls (from 4 in. to 8 in.) and I'm pleased with the result.