Repair Snowblower Chain Drive Sprocket

[Lost Pup 172]

Snowblower has been working well but I noticed a bit of noise. Unbolted the cover and checked the drive sprocket and found that the two set screws were rusted tight and not gripping the shaft. The result was the sprocket was sliding left and right on the shaft and stretching the chain and the chain was just eating into the black plastic cover. Loosened the chain adjustment and disassembled the side assembly and the gear slid right out. Tried the normal methods but ended up drilling out the two setscrews to the original dimensions. The pic with the drive sprocket has a small spring left of the original threads right next to it. I just restore an old South Bend Drill press and this was my first chance to use it.

Noticed on the outer bearing shell two small holes about 90 degrees apart and both were clogged. I used a needle point adapter on the grease gun and the bearing did take grease. I assembled with the two small holes centered on the grease fitting. I aligned the pulley and when complete I greased the bearing. Snapped pics showing the inner and outer bearing both passing grease although the outer plate leaked grease as well. I did shave the threads of the grease fitting because it would not allow the outer plate to completely close when tightened. Chain is at the end of adjustment so I will pick up another to replace.

Pics tell the story. Comments Welcome

[Kelly 1,030]

Nice, mine has one set screw that will not budge, and the gear was loose on the shaft, but the teeth are getting worn, I need to replace the drive gear, and since the chain broke this morning now is the time.

[Lost Pup 172]

I was looking here for the sprocket and chain.

McMaster

[varosd 1,185]

Great picture! I need to inspect mine now!!!

[Lost Pup 172]

Measurement Pics of the snowblower drive gear.

Unit is a 79360 SnowBlower and the gear is a 14 tooth 7/8 shaft.

[GlenPettit 1,717]

'Lost Pup': really great detailed instructional pictures, you made it all look so easy, now I have the confidence to go ahead do it.

The part numbers (& prices would too) really helped, plus all the details of your steps. Thanks,

Michigan Glen

[timo4352 147]

Bump

'cause winter is coming and my blower is kinda noisy

Good info to review

[SousaKerry 502]

That sprocket would be a 40b14 with 7/8 bore in power transmission speak. 

[squonk 42,554]

Since it's becoming blower season, I'm planning on replacing my tall shoots chain and will go to TSC. Will I need a chain breaker to cut the bulk #40 chain or is there another way to get the proper length?

[timo4352 147]

I'd just grind the ends off with whatever you got and pop in the master link.

I'm off to look for some chain now myself - I just pulled mine off - and I'm no expert but I think 8 inches of sag in a 50 inch chain may be a little excessive

What do you the real experts think?

[Wyattrrp 59]

I think last year Kelly posted pics of how to grind off one side of the head of the link male pin until flush with side of link, then stand a small socket wrench, like a 1/4" on the work bench and place the link pin over the socket hole with flush side up.  Use a punch and tap the pin out.  This leaves the female opening of the end link ready for the master link.  On my 79360  I believe it took 51 male links, including the master to fit but double check yours.  It is under 5 ft long, so TSC sells 10 ft leaving you a spare.  Use the old chain to wrap the front time in the middle of tread by letting tire pressure down, adding the chain cut to correct length to wrap the treads semi-snug, then inflate the tire and the chain stays put.  It helps steering in snow and ice quite a bit.

[squonk 42,554]

Started working on the blower chain and found the tensioner sprocket is shot. What's the best place to get one of those?

[Wyattrrp 59]

Read this thread from a year ago.  I chimed in about paying TSC $20 for one #40 17 tooth sprocket then finding them online at Thebigbearingstore.com for only $8.25.  My note is 2/3 thru the thread and I give 2 links to that website for both the sprocket and the shaft bearing. They will ship overnight for $$ but an option is US post Office for light packages like 1 or 2 sprockets. O)nly 3 days to deliver with the regular mail.  To mail the chain would be heavy so too expensive so TSC may be best bet.  WHC160 used my suggestion and found the sprocket was a bit thinner than original stamped / riveted sprocket so he added a washer or 2.  Mine already had washers so I was ok as is.

 

Here is the thread.  Doesn't hurt to save $10 for a simple sprocket.  By the way it can use either a 17 or 18 tooth sprocket as long as it is a #40 tooth for the #40 chain. And the bearing for the shaft was inexpensive to. 
 

WHC160 included good photos of the project too.

 

Good luck.

Wyatt

[Wyattrrp 59]

Just a reminder they sell both 1/2" and 5/8" inner shaft hole size so be sure your bolt is the correct size.  I have had 2 79630 blowers with 1/2" sprocket holes.

[squonk 42,554]

I picked this sprocket up at TSC. $19.99 China made but it seems well built and solid.

 

 

This sprocket is thicker than OEM so I had to take the spacer out and use 2 washers to line it up. I need the idler too and of course they only stock 1. Luckily there's another TSC a couple miles from work.

 

[squonk 42,554]

Got the 2nd sprocket installed, cut  the chain and now found out the drive shaft sprocket was loose and the bearings are shot on that too. used heat and got the set screws out of the sprocket. I know there are cheaper places but Napa sells the bearings and collars as # GRA014RRBG for $18.00 ea. This blower looked hardly used when I got it and the P'O had never used it. Cant believe the amount of wear. Thankfully the auger bearings are tight and quiet as a mouse.

[squonk 42,554]

I discovered the TSC sprockets were a slightly smaller diameter. I cut the chain to the same as the original chain. It was now too long with the TSC sprockets. I removed another link and had to use a repair link along with the master link to connect. I now can adjust the chain to about 1/2' deflection with the adjustment at mid point.

 

 

[timo4352 147]

Thanks to the good people here I now know that a sealed bearing is greaseable. Last weekend I disassembled my blower to get at the bearings, removed the seals, (really never knew you could do that) cleaned and greased the bearings and reassmbled. I replaced the chain with one from TS. I can't say it is really very quiet, but better than it was. I'll try it out this season and see how it does - before I spend $200 on all new bearings. If and when I do I'll want to get some grease fittings in there somehow.

[squonk 42,554]

Got mine all together and it's noisy. I'm staring a new thread about it.