UTV Product Reviews

Yamaha Rhino Clutch Sheave Installation

Yamaha Rhino Clutch Sheave

MKS Performance - Clutch Sheave and Duner's Kit Install

KMS Performance Clutch Sheave and Duner’s Kit Installation

What is a CVT?

The job of the transmission is to change the speed ratio between the engine and the wheels. The transmission uses a range of gears — from low to high — to make more effective use of the engine’s torque as driving conditions change. The gears can be engaged manually or automatically. Today’s side x side vehicles all use a type of automatic transmission called a continuously variable transmission or CVT.

Unlike traditional automatic transmissions used in cars that are much too heavy for a side x side vehicle, CVTs don’t have any sort of gears. The CVT operates on a pulley system that allows an infinite variability between highest and lowest gears with no discrete steps or shifts.

CVTs used in Rhinos, RZRs, Rangers and Prowlers have three basic components:

  • A rubber belt
  • A variable-input “driving” pulley
  • An output “driven” pulley

The variable-diameter pulleys are the key to a CVT. Each pulley is made of two cones facing each other. A belt rides in the groove between the two cones. When the two cones of the pulley are far apart, the belt rides lower in the groove, and the radius of the belt loop going around the pulley gets smaller. When the cones are close together, the belt rides higher in the groove, and the radius of the belt loop going around the pulley gets larger.

One of the two pulleys is connected to the crankshaft of the engine. This pulley is typically called the drive pulley. The second pulley is called the driven or output pulley because the first pulley is turning it. The driven pulley transfers energy to the transfer case and onto the differentials, through the axles and out to the wheels.

On a Yamaha Rhino, the clutch sheave is part of the drive pulley (right side in above image). When clutch sheaves are machined, it allows the cones on the drive pulley to collapse even further which forces the belt even higher between the cones.  This translates to a higher gear.

In this image, the engine is at low rpm.  The drive pulley cones are far apart causing the belt to ride low (smaller radius).

In this image, the engine is at high rpm.  The drive pulley cones are far apart causing the belt to ride high (larger radius).

When one pulley increases its radius, the other decreases its radius to keep the belt tight. As the two pulleys change relative to one another, they create an infinite number of gear ratios.

Clutch Sheave:

KMS Performance Machined Clutch Sheave    Machine Sheave vs. Stock Sheave

KMS Performance Machined Clutch Sheave
Clutch sheave is precision machined to provide better performance and increase top speed. The sheave is designed to allow the rollers to expand further than an OEM sheave. This additional expansion will increase top speed of the machine.

Clutch Spring:

KMS Performance - Duners Kit: Clutch Spring and weights  

KMS Performance Duner’s Kit
Clutch weights and Secondary Spring for better hill climbing.


Remove seat base and plastic in front of seat. Remove bolt from inner/front seat base that goes around below shifter.

Remove cover

Cover removed – Sheave is on the right.

Remove sheave “guard”

Guard removed

Bolts inserted to loosen belt

Clutch sheave removed from Rhino.

Old clutch sheave removed. There are eight weights.

Old weights are removed from the teflon covers

New weights are pressed into old teflon covers

New weights are all in place

Weights are greased and installed in the new sheave


Sheave is assembled


Now it is time to remove and replace the secondary spring (part of the Duner’s Kit) from the secondary sheave. This is a special spring removal tool and wrench from Yamaha.  Changing the secondary spring is very difficult (not recommended) without these tools.

A little persuasion is needed to get the secondary sheave in

Reinstall sheave

Reinstall belt.  I decided to put a new belt on.

Reinstall cage


Test before putting cover back on.  Left side is low rpm.  Right side is high rpm.

Installation performed by Paul Hart – Hart’s Rhino Motorsports

Thanks to Paul for letting me look over his shoulder while he worked on my Rhino.


Website:KMS Performance

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