Snowmobile Polaris 550 IQ / 550 Shift (2012 year). Instruction - part 8

32

THE PERFECT FIT

Rear Suspension Adjustments

Initial Spring Preload Setting (Sag Method)

To set up the rear suspension torsion 
spring preload, measure the distance 
between the ground and rear bumper. This 
is measurement X.

Take the first measurement with no rider 
and with the rear suspension at full exten-
sion. 

Tip: The rear bumper may need to be lifted 

upward slightly to fully extend the rear 
suspension.

Next, have the rider drop down hard on 
the seat and bounce up and down several 
times, collapsing the rear suspension. 
With the rider seated, measure the dis-
tance between the ground and the rear 
bumper at the exact location used for 
measurement X. This is measurement Y.

To determine sag, commonly referred to 
as ride-in, subtract measurement Y from 
X (sag=X-Y). If the measured sag is 
incorrect, adjust the FRA position and/or 
rear torsion spring preload.

Tip: This is only an initial setup, and final spring preload may vary based on rider 

preference and riding conditions. Accessory springs with a higher load rat-
ing are available for some models. Please see your dealer for availability.

Suspension

Recommended Sag

Adjustment

See 

Page

IQ (121)

4-5 inches (10-13 cm)

Torsion Spring 

Preload

33

IQ Comfort 

(136)

4-5 inches (10-13 cm)

Torsion Spring 

Preload

33

X

Y

33

THE PERFECT FIT

IQ Rear Suspension Adjustments

Torsion Spring Preload

To adjust rear torsion spring preload, rotate the three-position cam using 
the engine spark plug tool. Adjustment is easiest when the cam is 
rotated from low to medium, and then to high. Rotating directly from 
low to high will require significantly more effort.

Different rate torsion springs are available if a firmer ride is desired. See 
your dealer for more information. 

Limiter Strap Position (Ski Pressure)

Ski pressure is set at the factory to 
deliver the optimum balance 
between ride and handling. If a 
rider prefers more ski pressure for 
improved steering performance, 
adjustments can be made to the 
front limiter straps. Tighten the 
straps to increase ski pressure. 
Loosen the straps to reduce ski 
pressure.

1. Remove the nuts and flat 

washers from the upper limiter 
straps.

2. Relocate the straps to the desired position.

3. Reinstall the nuts and washers. Tighten securely.

Soft

Medium

Firm

Upper

Nuts

34

THE PERFECT FIT

IQ Rear Suspension Adjustments

Suspension Coupling

On all POLARIS snowmobile rear suspensions, there are two torque 
arms that control the movement of the rail beam. Prior to the advent of 
suspension coupling, these torque arms could move independently of 
each other. Rear suspension coupling links the movement of the front 
and rear torque arms to each other. 

There are two types of rear suspension coupling.

Front To Rear Coupling and the Front Rear Scissor Stop 
(FRSS)

The front rear scissor stop (FRSS) couples the movement of the front 
torque arm with the rear torque arm and limits the amount of indepen-
dence between the movement of the front torque arm and the rear torque 
arm.

When hitting a bump, the front torque arm starts to compress. The FRSS 
links that movement to the rear torque arm, causing it to compress and 
raise the rear suspension up as one, allowing the suspension to hit the 
bump only once and reducing kickback. 

The factory setting is usually adequate for all riders and conditions.

35

THE PERFECT FIT

IQ Rear Suspension Adjustments

Suspension Coupling

Rear To Front Coupling and the Rear Rear Scissor Stop 
(RRSS)

The rear rear scissor stop (RRSS) couples the movement of the rear 
torque arm with the front torque arm and limits the amount of indepen-
dent movement between the rear torque and the front torque arm.

Adjusting the RRSS either allows more weight to transfer to the rear for 
more traction, or allows less weight to transfer to the rear, resulting in 
improved cornering performance. An adjustment dot is located on the 
RRSS. This dot is on the longest end of the scissor stop. 

Rear Rear Scissor Stop (RRSS) - Attributes

Moving the RRSS to a higher position will have the following effects on 
the suspension:
• Reduced weight transfer
• Improved chatter bump ride
• Improved cornering performance

• Increased load carrying capacity (2-up)