Snowmobile Arctic Cat (2008 year). Manual - part 148

7-152

4. Remove the button-head screw from the nitrogen

valve in the shock body.

FS040

5. Insert the needle squarely into center of the nitro-

gen valve to release the pressure.

FS016

6. When the shock is fully discharged, pull the needle

away from the reservoir in a straight, smooth

motion.

7. Loosen (but do not remove) the bearing bleed

screw.

FS013

8. Loosen and unscrew the bearing assembly from

the shock body.

FS006

9. Remove the shaft assembly from the body tube

and place it on a clean, lint-free paper towel.

10. Remove the shock from the vise and pour shock

oil from body tube into a proper disposal con-

tainer. DO NOT REUSE OLD SHOCK OIL.

11. Clamp the body cap of the shock securely in vise

with the open end of the body tube pointing up. 

12. Loosen and remove the nitrogen valve from the

body.

FS014

13. Remove the shock body from the vise; then invert

the shock body and place it on a folded shop towel

open end down.

14. Using compressed air (NEVER USE HIGH

PRESSURE NITROGEN), insert the air gun noz-

zle into the nitrogen valve port and blow the IFP

out of the shock body and onto the folded shop

towel.

FS012

! WARNING

Point the nitrogen valve away from face and body to
avoid injury when discharging or charging the
shock.

7-153

7

15. Clean the body tube, reservoir tube, and the IFP

with solvent. Dry with compressed air in a well

ventilated area.

16. Set body assembly aside on a clean, lint-free

towel.

17. Clamp the shaft eyelet securely in vise with the

piston end up.

18. Remove the piston lock nut from the end of the

shaft.

FS008

19. Hold the tip of a screwdriver against the end of

shaft; then hold the piston assembly under the top-

out plate and lift upwards. 

FS009

„NOTE: Keeping the components in order is criti-
cal for proper performance of the shock absorber.
Doing steps 20-21 properly ensures that proper
order is kept. 

20. Slide the piston assembly onto the shaft of the

screwdriver. Pull the screwdriver away from shock

shaft while supporting the piston assembly and set

this on a clean, lint-free towel.

FS010

21. Slide bearing assembly off of shaft.

22. Remove the bleed screw from the bearing and set

them both on a clean, lint-free towel.

REBUILDING

1. Using a pair of snap ring pliers, remove the snap

ring from the bearing housing. Using fingers,

remove the FIST scraper from the housing. Using

a scribe, remove the O-ring from the inside of the

FIST scraper by “spearing” the seal with the point

of the scribe and pulling it out.

FS011

2. Using a scribe, remove the U-cup wiper and O-

ring seals from the bearing housing. 

3. Thoroughly clean the FIST bearing, bearing hous-

ing, and piston assembly with solvent. Dry with

compressed air in a well ventilated area.

! CAUTION

Use care when passing the bearing over the shaft
threads not to scratch the inside of the bearing
assembly.

! CAUTION

Care must be taken when using a scribe to remove a
seal. Always spear the seal with the point of the
scribe. Do not attempt to wedge the scribe behind
the seal as this could cause damage to the seal
groove and compromise the performance of the
shock.

7-154

4. Using a scribe, remove the O-ring seal from the

IFP.

5. Install the new, well lubricated O-ring into the

FIST bearing. Check to make sure the O-ring is

properly seated and is not twisted. 

„NOTE: To aid in proper seating of the O-ring, it
may be advisable to use a soft, blunt object (non-
writing end of a pen, etc.) to push it in.

6. Install the new, well lubricated O-rings into the

bearing housing making sure the shaft O-ring is in

the groove next to the DU bushing and that the O-

rings are properly seated and not twisted. It may

be advisable to use a soft, blunt object to push it in.

7. Install the new U-cup seal into bearing. U-cup

should be installed so the cupped end is facing the

DU bushing inside of bearing. Check to make sure

seal is properly seated. It may be advisable to use a

soft, blunt object to push it in. 

8. Install FIST bearing into housing. Check for

proper orientation of the FIST bearing. The

stepped side of the FIST bearing should be visible. 

9. Using a pair of snap ring pliers, install the snap

ring into the bearing housing. Check for proper

orientation of the snap ring. The flat side of the

snap ring should be visible. Check to make sure

the snap ring is properly seated.

FS007

10. Install the new, well greased O-ring onto the IFP.

11. Replace the bearing bleed screw O-ring. 

ASSEMBLING

1. Clamp shaft eyelet securely in vise and place a

seal tool on end of shaft. 

2. Lubricate the bearing assembly seals with an

assembly lube. Slide the bearing assembly onto

shaft with the FIST bearing facing the eyelet. This

should be done in a single smooth motion to avoid

damaging the seals.

3. Hold the piston assembly from underneath the top-

out plate and place the end of the screwdriver onto

the end of the shock shaft. Slide the piston assem-

bly onto the shaft end. Check to make sure the pis-

ton assembly is seated properly and install the

piston lock nut. Tighten nut to 18 ft-lb. Remove

shaft assembly from vise and set it aside on a

clean, lint-free paper towel.

FS008

4. Clamp the body of the shock securely in the vise

with the open end of the body facing up.

5. Lubricate the IFP O-ring with assembly lube and

wrap a new piston ring around it.

6. Insert the IFP into the shock body (with the dished

side facing up toward the open end of the shock

body) to just below the bearing threads. 

FS015

7. Using Floating Piston Installation/Location Tool,

install the floating piston while using the inflation

needle to vent the shock body.

„NOTE: Refer to the Rebuildable Shock Specifi-
cations sub-section in Section 1. 

„NOTE: Depth is measured from the edge of the
body opening to the outside edge of the IFP (not
the center depression of the IFP).

8. Lubricate the O-ring on the nitrogen valve with

assembly lube and thread it into the body. Tighten

securely.

7-155

7

FS014

9. Fill the body tube with oil to the bottom of the

bearing threads. Wrap the new piston band around

the piston making sure the rounded edges face out.

Insert the shaft assembly into the body tube.

Slowly push shaft into body until piston assembly

is approximately 12.7 mm (0.5 in.) below the oil

surface. 

10. Slowly stroke the shaft assembly up and down

over about a 1-inch range two to three times being

very careful not to pull the piston assembly out of

the oil. 

„NOTE: At this point, there should be no air bub-
bles rising from the piston assembly.

11. Top off the shock body with oil and slowly pull the

shaft up until the piston assembly is about in the

middle of the bearing threads.

12. Holding the shaft in that position, slide the bearing

assembly down the shaft and start threading it into

the body by hand. Oil should flow out of the bear-

ing bleed hole.

13. As the bearing assembly is being threaded down, it

will contact the damping piston assembly and pull

it down into the shock body with it. As the bearing

is being threaded in from this point, be sure the

damping piston assembly stays in contact with the

bearing.

14. When the bearing is threaded all the way down,

thread the bleed screw into the bearing assembly

and tighten it securely.

FS013

15. Tighten the bearing assembly into the body.

FS006

16. Push the shaft all the way down until the eyelet

lightly contacts the FIST scraper on the bearing

assembly. It should go all the way down without

any feeling of contact or interference. 

„NOTE: At this point, DO NOT attempt to pull the
shaft up out of the body.

17. If there is any interference while pushing the shaft

into the body, the IFP is in the wrong location.

18. If there is no interference, proceed to step 19.

19. Maintain the shock in the vise.

20. Make sure the nitrogen valve is directed outward.

21. Insert the needle squarely into the center of the

nitrogen valve (taking care that the valve is

directed away from face and body) and pressurize

the reservoir to 200 psi. The shock shaft should be

fully extended from the pressure before the final

pressure reading is taken. Continue charging while

pulling the reservoir away from the needle using a

smooth, straight motion. Keep the reservoir as

straight as possible to prevent the needle from

bending. As the reservoir and needle separate, a

“popping” sound should be heard.

! WARNING

If there is interference, unthread the bearing assem-
bly from the body and repeat steps 4-16 of Assem-
bling. Failure to repeat the steps and rid the shock of
the interference may cause damage to the shock
resulting in improper shock performance and could
cause operator injury.