Snow Thrower Self Propelled Drive Problem

Specifics: MTD Snow King 7.0 HP
Model: 31AS3DDE29 546046
Serial: 1H045L10322
Engine Mfg: Tecumseh

This is my friends snow thrower. I don't have any manuals, etc
He said I could use it if I can fix it, and winter is coming so I need to get going on this! It is 3 or 4 years old, a couple years ago we got a big late winter wet snow storm, with over 1' of snow. He was doing his driveway with it and he is not mechanically inclined, he says the self propelled drive just stopped. I have a feeling there may have been too much snow for how fast he was trying to go. I thought it may be easy to fix, maybe a belt or something easy.

I propped up the machine and I see the rear wheels have 1 axle with a gear. A matching gear is in contact with it and the wheels spin freely when pushed. This second gear is on a rod that goes into a plastic black box. Out of this black box there is a rod that connects to a belt drive system. The belt looks OK to me, it is not broken. This belt system is driven by another belt but this belt is not flat like the first one I described, this belt has teeth. It seems OK too.

If it isn't a belt what could it be?

Any help is appreciated.

SD

 

The black plastic box is the Transmission Assembly it will need to be replaced. Part number 918-04296B around 145.00 $ there are no parts available only a complete replacement. I didn't think that MTD could cheapen their product any more than it was and than they made these models.

AJ

 

Would changing the transmission assembly be something I could easily do?

 

You should confirm that I guessed correctly first. With the machine turned up on the blower housing turn the wheels if this turns the big gear & the little gear that goes into the transmission but not the pulley the transmission is bad. If the wheels turn but not the gears than it could be that a pin is missing in the big gear. If you can turn a wrench you should be able to fix it.

AJ

 

When turning the wheels the gears turn, nothing out of the transmission. Is this assembly easily replaced?

 

OK, I removed the old transmission, ordered a new one and replaced it. But it didn't fix the problem. When I pull the bar to engage the self propelled drive the blower jumps a little bit but it doesn't go. Any ideas?

 

I know this is an old thread, but figured someone else might find it while searching for a solution to this exact problem ... My MTD snowblower had this EXACT problem (would jump a bit when engaging the self propelled wheels, but no positive engagement or power to the wheels) and after cleaning the friction plate and drive wheel without any improvement (cables were all properly adjusted and making good contact), I discovered that the problem was with the drive belt coming off the engine.

The belt itself was fine, but the spring that holds the belt tensioner against the belt had rusted and broken ... no tension equals no power to move the wheels. I found a similar, but less strong, spring in a box and made a temporary fix, but I'll pick up a proper replacement spring tomorrow at the snowblower repair shop. The belt and tensioner can be found under a plastic cover on TOP of the unit, just behind the blower chute, and this assembly is pretty much the same among a wide variety of brands and snowblower models - not just MTD.

It is a relatively simple procedure to get to the tensioner and spring, but it's not an obvious issue if you don't know what you're looking for. I hope this is helpful to others, because I was very frustrated for several days, wondering what was going on...

Tomorrow I'll be happily blowing snow again!

Regards,
Steve