Your ATV or UTV's CVT (continuously variable transmission) has two clutches that work as a pair. When one wears out, owners often ask: which one do I actually need to replace? Here is a plain-language breakdown.
The Primary Clutch (Drive Clutch)
The primary clutch bolts directly to the engine's crankshaft. Its job is to engage and disengage power and to squeeze the belt as RPMs rise.
- At idle, the primary is disengaged — the belt sits loose and your machine doesn't creep.
- As you rev the engine, centrifugal weights inside the primary swing out and clamp the belt.
- The harder you rev, the tighter it squeezes, which changes the effective gear ratio.
Common failure signs: slipping or jerky take-off, engagement at unusually high RPM, rattling at idle (worn weights or bushings), or a burnt-belt smell after normal riding.
The Secondary Clutch (Driven Clutch)
The secondary clutch is connected to the drivetrain. It reacts to the primary: as the primary squeezes the belt and forces it to ride higher, the secondary opens up to let the belt ride lower — together they create an infinite range of gear ratios. The secondary also handles torque sensing: under load (climbing, mud, towing) it clamps harder to keep the belt from slipping.
Common failure signs: poor top speed, sluggish backshift when you get on and off the throttle, or the machine feeling "stuck in high gear."
Can I Replace Just One?
Yes — primary and secondary clutches are sold separately, and if only one is worn there is no requirement to replace both. That said, the two wear together: if your primary failed at high hours, inspect the secondary's sheaves, bushings, and helix while you have the CVT apart. Replacing a glazed or worn belt at the same time is cheap insurance.
How to Tell Them Apart When Ordering
- The primary is the smaller clutch on the engine side; it has visible centrifugal weights and a spring.
- The secondary is the larger clutch toward the drivetrain; it has a helix and torsion spring.
- Each has its own OEM part number — check the stamping on the unit you are replacing and match it to the fitment table on our product pages.
All of our primary and secondary clutches are direct bolt-on replacements — no modifications needed — and carry a 12-month limited warranty against manufacturing defects (see our Warranty Policy).