Clutch & Drive Belts
About Clutch & Drive Belts
A snowmobile's drive belt links the primary clutch on the engine to the secondary clutch on the drivetrain, so all the power that reaches the track passes through it. The belt wears with use, and so do the clutch parts that decide how it grips, which is why belts, springs, sheaves and drive gearing share this category.
Belts are sized by width and outside circumference, written in the titles as, for example, 1-15/32 inch W by 44-5/8 inch OC. Use the numbers printed on your old belt or given in your manual, because a belt of the wrong length changes how the clutches engage and shift. Makers sell several named grades, and each listing states the sleds it suits.
The helix, primary spring and movable sheave are clutch parts that set when the clutch engages and how quickly it shifts, so the right choice depends on your engine, altitude and track. At the other end of the drive, sprockets and chain set the gearing. The tooth count is in the listing, such as the 41T and 48T sprockets shown here, and the chain has to match the chain case.
Brands in this category include D.I.D, Comet, EPI, Ultimax and Parts Unlimited. See also Engines & Components and Other Parts. Fit depends on make, model and year, so pick your sled in the Ride Finder at the top of the page.
FAQs on snowmobile drive belts and clutches
How do I find the right drive belt size for my snowmobile?
Read the part number and the width and outside circumference marked on your old belt, or take them from the owner's manual. Listings here show width (W) and outside circumference (OC) in the title. Match both numbers, and use the Ride Finder to confirm the belt is listed for your model.
When is a drive belt too worn to keep using?
Look for cracks, frayed or missing cogs, glazed sides, and a belt that has worn narrower than the minimum width in your manual. A belt that slips or squeals when you take off also needs inspection. There is no single mileage that suits every sled, so inspect it regularly, and many riders carry a spare.
What does a clutch helix do?
The helix is the ramp inside the secondary clutch. Its angle controls how the secondary clutch twists and opens as load changes, which affects engine speed, throttle response and how the sled shifts. Changing the helix alters clutching, so follow the maker's tuning chart for your engine and altitude.
Does a new drive belt need to be broken in?
Most belt makers advise a short, gentle break-in with moderate throttle and no hard acceleration, so the belt beds in to the clutch faces. Read the instructions that come with the belt, since the recommended distance and method vary.
What happens when I change a drive sprocket?
Changing the tooth count alters the gear ratio between the engine and the track. Putting more teeth on the upper sprocket gears the sled taller, and fewer teeth gears it lower. The chain length and the chain case limit which combinations work, so check your manual or the listing.
