Craftsman snowblower problem!

Hello.
I have an older (about 20yrs from what I've read) Craftsman snow thrower/blower (model "536-90520 HC2") with a problem. It is a self-propelled model.
I bought the unit from the previous owner of my home. I tried it out about a week ago (for the first time) and it wouldn't start. I took it to a local shop for a tune-up, and they get it running great after a minor carb cleaning.
I got it home and used it for the first time last night. It worked great for the first half of my driveway, then all of a sudden the wheel drive stopped working. The auger drive still works fine, the engine still runs fine, but the 4 forward and 1 reverse gears don't do anything anymore (no more self-proppeled)!!
Could anyone give me some advice/guidance on what the possible cause could be? Would it be something I could fix easily myself?
Please respond by email and also here for anyone else that may be having this problem.
Thanks,
Corey Dale cdale snipped-for-privacy@hotmail.com (remove the '.nospam')
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probally a broken drive gear cotter pin

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A lot of the self-propelled snow blowers use a constantly variable drive system that consists of a vertically-oriented flat plate, driven by a belt from the engine on a horizontal shaft. Another wheel with a rubber tire on it is pressed against the plate's flat surface and is arranged so it can slide left or right. On one side of center, the machine will go forward, on the other side it will go backward. The further out toward the edge you go, the faster the machine moves. These components often get oil and/or grease on them, so they only slip. Also, after 20+ years, the rubber has likely dried out and no longer presses against the flat plate with enough pressure to drive the wheels.
First step would be to clean the flat plate and rubber surface with something like isopropyl alcohol to remove all the oil and grease. If you can find some rubber roller restorer fluid, often used on old typewriters and even some printers and tape decks, you could apply some of that to the rubber tire. I don't think there's an adjustment you can make that will bring the rubber tire any closer to the flat plate, but it might be possible to loosen the plate's mounting screws and slide it on the shaft a bit closer to the rubber tire-equipped drive mechanism. If all else fails, you'd have to replace the rubber tire and/or the wheel it's mounted on if they're inseparable.
This same mechanism is used on Toro, MTD, and most likely all of the under $1200 snow blowers that have a solid rear axle and several forward and reverse speeds.
Bob M.
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maybe the belt just broke , or the tension pulley isnt working and the belt is just slipping on the pulley
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It could be that the drive belt for the wheels has come off the pulley. My old snowblower which was similar to the Craftsman models had a vinyl cover just behind the discharge chute and in front of the engine. Remove this cover (snowblower engine OFF) and inspect the belt drive system by having someone helping you by engaging and disengaging the drive clutch on the handle of the snowblower.
You should see which belt is being engaged, or should I say, attempting to be engaged. There is an idler arm assembly that keeps the belt on the pulleys and also engages the power when the clutch lever is engaged. This is where I would look for the belt to be disengaged as it is a place where a lot of wear could have happened to the parts on a machine 20 years old.
If the belt assembly is engaging ok (belt gets tight when the clutch is engaged) then as one other person suggested, look for the drive shear pin assembly which will require the removal of the rear cover on the snowblower. Good luck
--
Ron
Port Dover Ontario
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Hi again. Thanks to anyone who posted to help me out, as I managed to identify and fix the problem!
I first opened up the shroud on the opposite end of the motor from the pull cord. This shroud covered two belts - one for the auger system and one for the engine. Both belts were in good shape, and were under good contact pressure with the engine in gear and the auger drive engaged.
I then opened up the cover over the wheel drive assembly. The problem was immediately clear, as one of two chains in this housing had come off it's gears. Apparently a free flywheel with gears that is used to keep proper tnesion on the chain that drives the wheel had slipped (not tightened enough during the tuneup, I suspect), giving two much slack. The chain slipped off and so the snowblower wouldn't go! I put the chain back on the sprockets, adjusted the small flywhell/spocket as needed, and could tell even before I started it back up that it was working fine as I could hear the sprockets turning as I pushed the snowblower in neutral.
It started up with no problems, and went like the wind when I put it in gear.
Thanks again for the help and ideas! It was a great learning experience for me, and it was fascinating to see how simple the whole drive system was (with the rotating disc and rubber wheel).
Regards, Corey Dale Edmonton, Alberta "Home of the Heritage Classic Outdoor NHL Hockey Game!!"
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