Monday, February 16, 2015

Curt's Snowblower repair service

Sure looks like I've got a new career huh? With all the snow we've had its not surprise really.

In reality last night Angie's grandparents mentioned that they were giving their snowblower to her parents. Angie's folks have never had a snowblower before and its really time, they're not getting any younger... Since the machine in question hadn't been run in a couple years I offered to haul it to our house and get it going. It turns out that this snowblower is the exact same model as our snowblower, they're 849 apart by serial number. How weird is that?

The first part was easy, I changed the oil, it must have had conventional oil in it, the stuff was thick like honey and dirty too. I put some good Mobil 1 5w40 in it. I pulled the plug which looked perfect, then pulled it over a few times to prove we had spark which we did. With the plug back in I hit the electric starter (110v electric starters are awesome) and while it would spin over good it wouldn't fire. I squirted some gas into the carb and it fired right up. I think it would have fired eventually but this was easier.

On a trial run the transmission was slow to respond and the lever was sticky, it also didn't seem to want to pull strong. I tipped it up on the auger and took a look inside. The transmission system in these is pretty simple, theres a flat disc which is spun by the engine, a wheel pushed against the plate in a perpendicular plane (like a T) takes that motion and uses it to spin the axle. Speed is adjusted by moving the wheel farther toward the rim of the disc. Reverse happens by moving the wheel to the other side of the disc.

The whole system is visible here, the disc is at the bottom of the picture, the wheel is above and to the right, in its fastest forward setting. The axle the wheel rides on drives the chain which comes to the gear in the foreground on the left which drives an intermediate shaft which turns a smaller gear at the far left. That gear drives another gear which turns the axle which is at the bottom of the picture under the disc.

The sticky transmission turned out to be a lack of lubrication where the wheel sides on its shaft . I greased that up with some Mobil 1 synthetic axle grease. The lack of power was slack in the cable that pulls the wheel up to the disc. This took some thinking about, there are two adjustments, one for the cable to its attachment point, then you can rotate the attachment point itself for a finer adjustment. It boils down to how hard you're willing to hold the lever, theres a spring inside (visible in the pic above just to the right of the big chain gear) that actually pulls the wheel up meaning you can't really over tighten the cable. So I got that to a point where it wasn't too hard to hold and still provided plenty of go.

With that snowblower all worked out I turned my attention to our snowblower. We got it when we moved into the house, Angie traded massages to a couple who were moving south. It was barely used when we got it and now I see it has a 2006 manufacture date so we got it the year it was made. Ours had been a little finicky about reverse lately so I wanted to tighten up the cable a little, that was the easy part. I also found a grease fitting that lubricated the intermediate shaft which makes it WAY easier to move the machine when its not powering itself.

When I lubricated the other machine it was difficult but possible to squeeze grease into the zerk fitting. When I tried it on this one the fitting came off. It turns out the fitting is just press fit into the intermediate shaft, there are no threads. The problem here is two fold, the fitting has to go in after the shaft is put into position and I was unable to get that wheel off my snowblower. This was extra funny because I was unable to get the right side wheel off the other machine. In both cases I think with a little heat the wheel would come right off but it was so cold out I couldn't get my propane torch to come out. As I write this I realize another thing to try would be to pull the pin that holds the wheel on and run the machine around a little, maybe the motion of turning the shaft in the wheel would slide it off, at least it would work some penetrating oil in.

Anyway I managed to get some grease into the intermediate shaft and wedged the fitting back on. I have my doubts that it'll stay where its supposed to be. At some point I need to pull the shaft (again), thread it and put a proper threaded fitting in place, but that can wait for another day, I was freezing and as the sun was going down it was rapidly getting colder.

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