Rear Suspension
This section has been organized so each procedure can be completed individually and efficiently. The technician should use discretion and sound judgment when removing and installing components.
GENERAL INFORMATION
Quick acceleration and the ability to go through the turns with power are the most important handling qualities. This section explains how the skid frame functions to provide these two important handling qualities. Good weight transfer characteristics are needed for fast acceleration (shift of weight from skis to track) and for cornering (shift of weight back to skis to hold the front end in turns). Effective weight transfer depends on suspension tension, position of rider, and the position of the front arm limiter.
Removing Skid Frame NOTE: Many service procedures can be performed without removing the skid frame. Closely observe the note introducing each subsequent sub-section for this important information.
1. Loosen the jam nuts and the two track tension adjusting cap screws.
To understand how the suspension system works, think of the entire system in terms of three points; the skid frame rear axle center, the skid frame front arm, and the ski saddle center. Assume that the front arm functions as a stationary pivot point between the rear axle center and the ski saddle center. Also assume that the ski saddle center is the same height off the ground as the rear axle center. This produces the standard position arrangement.
744-947A
2. Place a support stand under the rear bumper; then remove the two cap screws securing the upper idler wheel assembly to the tunnel. NOTE: The support stand should hold the snowmobile level and not raised off the floor.
3. Remove the cap screws securing the front axle, idler axle, and rear suspension arm to the tunnel. 0728-180
Under acceleration when the center of gravity is transferred to the rear of the machine, the rear suspension collapses slightly. This brings the rear arm point downward and with the front arm stationary, the teeter-totter effect reduces the pressure on the skis, position A. However, for controlled cornering, more pressure is needed on the skis. So when the driver decelerates coming into a corner, the center of gravity is transferred forward, putting the required pressure onto the skis and reducing the pressure on the rear suspension, position C. This is essentially what weight transfer is all about — the shift of weight to the rear of the machine for positive traction and good acceleration or to the front of the machine for positive handling and cornering control.
IO115B
4. Remove the support stand; then tip the snowmobile onto one side using a piece of cardboard to protect against scratching. Remove the skid frame assembly.
REAR ARM SPRING TENSION
The rear spring tension is adjusted for the weight of the driver. Three possible adjustments exist: 1st block position — light operator 2nd block position — medium operator 3rd block position — heavy operator
End Cap REMOVING
1. Remove the lock nut, washers, and cap screw securing the end cap. 43
