Small Engines (Lawn Mowers, etc.): drive

Question
QUESTION: I have a ns1029del signature model snowblower. When I engage the traction drive clutch lever it will not move. friction wheel, drive wheel and belts all seem to be ok. I have noticed that the larger chain seems to be slipping. No broken teeth or spocket. also right axle has some play in the bushing and bearing. If I take weight off of the wheels and engage drive lever wheels will move but as soon as I set it on its wheels machine will not move. Can you suggest what might be the problem and is it something I can do myself. Thanks for your time

ANSWER: Are you sure the friction disc is not slipping?  Those rubber disc wear and will cause this problem.  How old is the blower?  When was the last time the rubber disc was replaced?

Let me know.
Eric

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QUESTION: The blower is about 5yrs old. the disc was replaced about a month ago and looks to be in good shape. Like I had mentioned the wheels do turn if I take the weight off of them therefore I do not think the disc is slipping. Would worn axle bushing cause the chain to slip? There is a lot of play in them. Thanks

ANSWER: Worn axle bushings could cause the chain to slip but you usually hear or feel the chain slipping as it produces a strong vibration/jolt as the chain slips on the sprocket teeth.  Many blowers seem to have a lot of play in the axle bushings.

Is there any adjustment on the friction disc?  Some are adjustable and some are held in place with a large spring.

Based on a Google search your blower was made by Murray/Noma.  

Just want to make sure the wheel pins are in the correct axle holes...did you recently remove the wheels or checked to make sure the wheel pins are in the correct axle holes?

When the pins are in the correct axle hole the wheel should not roll when the blower is in a drive gear and you try to roll it.

Let me know about the axle pins.

Eric

---------- FOLLOW-UP ----------

QUESTION: Thanks for your quick response. The wheels have not been removed and the pins seem to be in the correct axle hole. When I inspected the friction wheel I noticed that the larger chain is slipping every once in a while. Quite noticeable when you turn the wheels. What would cause that? (no broken teeth or damaged sprocket that I can see). I was told it may be the axle bushing but now not so sure. I had the friction disc replaced on this blower four times in the last 3 years which I think is a little excessive leading me to think there is something else causing the disc to wear out so much

Answer
Replacing the friction that often does seem excess.  There are many things that can cause the chain the slip.  It is often a combination of many little things that are wore but when all the wear adds up you get too much movement causing the chain to slip.

I'd start by inspecting the axle bushings and axle to see if you can see any wear.  really wore axles or bushings will show signs of wear such as a thinner axles where it rides in the bushing and the bushings will no longer be round...there will be wear is some areas of the bushing.

I would also check the bushings and bearing on the friction disc shaft.  The metal drive plate on the engine should be smooth and level all the way across the drive plate except in the center.  If the drive plate it wore it will wear friction discs.

Unfortunately there are not any specifications on the sizes (diameter) of the bushings and axles but you can measure the axle diameter outside the bushing area and odds are the shaft should be the same diameter.  You might be able to find some specifications on the bushing diameters...just look up the bushing part numbers on Google and do some searching.

I'd also replace the chain or compare the length with a new one...odds are there is some stretch.  The sprockets may not look wore but most likely are.  The best way to tell is again compare to a new sprocket.  You can feel sprockets but you need to know what you are feeling for...this just takes experience and seeing lots of sprockets.

Do you have a set of dial calipers and a flashlight?  Very useful tools for finding wore drive parts.

Eric