2009-2010 Honda CRF450R – Front Fork Rebuild

How To Rebuild The Forks On Your 2009 – 2010 Honda CRF450R

2009-2010 Honda CRF450r - Front Fork Rebuild - Featured

The Tools You Need Are:

  • 35mm Fork Cap Wrench
  • 49mm Fork Damper Wrench
  • 15mm Box Wrench
  • 17mm Socket
  • Torque Wrench
  • Waste Oil Bucket
  • Plastic Wrap
  • Vise
  • Pick
  • Flathead Screwdriver
  • Lots of Towels
  • Safety Glasses

The Fork Rebuild Parts:

The only parts you need is a new ’09-’10 Honda CRF450r front fork rebuild kit and fresh fork oil. I am using a pivot works kit that includes almost everything for this fork service. The only thing this rebuild kit is missing is a spring seat bushing, but those rarely wear out.

Pre-Service Notes

  • Start with your bike on a stand with the front wheel, brake caliper, and fork protectors removed.
  • I recommend opening the Service & Torque Specs in a new tab for easy reference.
  • If you need parts and tools, make sure to buy them here!
  • Pictures with captions are after the steps below.
  • If you need any help don’t hesitate to ask!

Front Fork Disassembly

  1. Your fork cap wrench might not fit due to the handlebar risers, so loosen the top and bottom fork bridge pinch bolts, then drop your fork below the top bridge.
  2. Tighten the lower pinch bolts, and loosen the fork damper with the fork still mounted in the bridge.
    1. Do not remove the cap; get it loose.
  3. Loosen the bottom pinch bolts and remove your fork.
  4. Turn the compression adjuster (top) and rebound adjuster (bottom) out, and write down the number of clicks.
  5. Hold your fork at an upright angle, loosen the fork damper, and slide the outer tube down to the axle mount.
  6. Drain the old oil from the outer tube and damper holes.
  7. Reconnect the damper and tube, then loosen the center bolt.
  8. Flip your fork, so the axle holder is facing up and install your damper rod holder tool by pushing down on the axle holder.
  9. Loosen the center bolt lock nut, then remove the center bolt, followed by the pushrod.
  10. Remove the rod holder, then remove the damper from the fork tubes, followed by the spring.
  11. Remove the fork cap from the damper and set aside.
  12. Pump the damper several times to drain the old oil.
  13. Remove the dust seal and stopper ring from the fork tubes.
  14. Aggressively separate the outer fork tube from the inner fork tube.
  15. Using a flathead screwdriver, carefully remove the slider bushing, followed by the guide bushing, backup ring, oil seal, and dust seal.
  16. Clean and inspect the tubes.
1 - Loosen The Fork Damper
1 – Loosen The Fork Damper
2 - Back Out The Compression Adjuster
2 – Back Out The Compression Adjuster
3 - Back Out The Rebound Adjuster
3 – Back Out The Rebound Adjuster
4 - Unscrew The Damper Unit From Fork Tube
4 – Unscrew The Damper Unit From Fork Tube
5 - Drain The Fork Tubes
5 – Drain The Fork Tubes
6 - Loosen The Center Bolt
6 – Loosen The Center Bolt
7 - Install Your Damper Rod Holding Tool
7 – Install Your Damper Rod Holding Tool
8 - Loosen The Center Bolt Lock Nut
8 – Loosen The Center Bolt Lock Nut
9 - Remove The Center Bolt
9 – Remove The Center Bolt
10 - Remove The Rebound Adjuster Pushrod
10 – Remove The Rebound Adjuster Pushrod
11 - Remove The Damper Spring Seat And Spring
11 – Remove The Damper Spring Seat And Spring
12 - Loosen The Fork Cap
12 – Loosen The Fork Cap
13 - Remove The Fork Cap
13 – Remove The Fork Cap
14 - Remove The Dust Seal And Stopper Ring
14 – Remove The Dust Seal And Stopper Ring
15 - Separate The Inner From Outer Tube
15 – Separate The Inner From Outer Tube
16 - Remove Slider Bushing, Guide Bushing, Backup Ring, Stopper Ring, And Dust Seal
16 – Remove Slider Bushing, Guide Bushing, Backup Ring, Stopper Ring, And Dust Seal

Related: What oil are you going to refill your forks with?

New Fork Rebuild Parts

I am using a new Pivot Works rebuild kit for this ’09-’10 Honda CRF450r fork service. This kit comes with all the bushings and o-rings needed for the tubes, fork cap, and center bolt.17 - New Pivot Works Fork Rebuild Kit This kit does not come with a replacement stopper ring, backup ring, or spring seat bushing, but it does NOT have new wear rings for the outside of the tube.

Fork Tube Assembly

  1. Wrap the end of the inner tube with plastic wrap, and apply a light layer of fork oil.
  2. Install the dust seal, stopper ring, oil seal, backup ring, guide bushing, and slider bushing.
  3. Install the backup ring with the shoulder side facing the axle holder, and the open side facing the end of the tube.
  4. Oil the end of the inner tube and join it with the outer tube.
  5. If you don’t have a seal driver, you can use the old oil seal for seating the new one.
  6. Remove the stopper ring, cut the old oil seal, and wrap it around the tube upside down.
  7. Push the old seal up to the new seal, and use the axle holder to drive the new seal into place.
  8. You don’t need to use much force for seating the oil seal, so don’t go crazy with the pounding.
  9. Install the stopper ring, check for any binding or dragging, then install the dust seal.
18 - Wrap Tube End With Plastic Wrap
18 – Wrap Tube End With Plastic Wrap
19 - Backup Ring Orientation - Shoulder Toward Axle Holder
19 – Backup Ring Orientation – Shoulder Toward Axle Holder
20 - Join Inner Tube And Outer Tube
20 – Join Inner Tube And Outer Tube
21 - Use Old Oil Seal As Seal Driver
21 – Use Old Oil Seal As Seal Driver
22 - Align Old Seal With New Seal
22 – Align Old Seal With New Seal
23 - Carefully Drive New Oil Seal
23 – Carefully Drive New Oil Seal

Tube Cap Service

  1. Remove the o-rings in order from the bottom to top, and keep track of their order.
  2. Clean the fork cap as thoroughly as you can.
  3. Match up your new o-rings, and install them in order with a light coating of fork oil.
24 - Strip O-rings From Fork Cap
24 – Strip O-rings From Fork Cap
25 - Match Up New Fork Cap O-rings
25 – Match Up New Fork Cap O-rings

 

 

 

26 - Install New Fork Cap O-rings
26 – Install New Fork Cap O-rings

Clean And Inspect

Clean and inspect the center bolt, spring seat collar, and pushrod.

Fork Damper Assembly

  1. The fork damper uses hydraulic force only, so we need to take extra care when removing air.
  2. Hang your damper, and fill it with 7.1 ounces of fork oil.
  3. Slowly pump the damper piston to remove any trapped air, and bleed excess fluid.
  4. If you pump too fast, you will remove too much fluid, so start with short strokes, gradually getting longer, until you reach a full stroke.
  5. You should feel the air getting pushed out, and see the excess oil exiting the drain hole.
  6. To install the fork cap, you will need to compress it slightly to catch the threads.
    1. If the cap installs without resistance, you do not have enough oil in the damper. The fork cap will be impossible to install if there is too much fluid in the damper.
    2. Slowly drain the oil little by little until the cap can install while maintaining resistance. The apparent issue with this is getting the oil level just right, and the air voided completely.
    3. Fortunately, this damper is self-regulating and will expel excess fluid on its own, which you will experience during testing.
  7. With the cap wrestled into place, torque the fork cap to 21-foot-pounds.
27 - Add 7.1 Ounces Of Fork Oil To Damper Unit
27 – Add 7.1 Ounces Of Fork Oil To Damper Unit
28 - Stroke Damper Half Way
28 – Stroke Damper Half Way
29 - Stroke Damper Full Length
29 – Stroke Damper Full Length
30 - Watch The Damper Bleed
30 – Watch The Damper Bleed
31 - Install The Fork Cap With Resistance
31 – Install The Fork Cap With Resistance
32 - Tighten And Torque Fork Cap To 21 ft-lbs
32 – Tighten And Torque Fork Cap To 21 ft-lbs

Related: How the front wheel hub works on your dirt bike.

Fork Damper Testing

  1. Double-check that the compression adjuster is backed out all the way, wrap the top of your damper with a shop towel, then fully compress your damper several times to blow out any excess oil.
  2. To test your damper, hold it horizontally, and completely compress the piston.
  3. Release the piston, then watch and feel how it extends.
  4. The extension should be smooth. If you see jitters or feel air moving around, you will need to remove the cap and try again.
  5. If everything looks good, compress your damper and wedge it somewhere vertically for 10 minutes.
  6. Take you damper out of time out and check for any leaks. Perform the horizontal extension test again, and if your piston does not extend smoothly, you will need to repeat the bleeding process.
33 - Compress Damper Unit To Blow Out Remaining Oil
33 – Compress Damper Unit To Blow Out Remaining Oil
34 - Test Damper Extension
34 – Test Damper Extension
35 - Damper Extension Test Passed
35 – Damper Extension Test Passed
36 - Compress Damper For 10 Minutes To Test For Leaks
36 – Compress Damper For 10 Minutes To Test For Leaks

Fork Assembly

  1. Tighten the center bolt lock nut against the rod, and measure the distance from the locknut to the end of the threads.
  2. The distance should be 16 to 18 mm.
  3. Install the spring seat.
  4. Place your spring in the fork tube, and install the fork damper unit.
  5. Thread the outer tube onto the damper, flip your fork, and install the rod holding tool.
  6. Install the pushrod.
  7. Double-check that the rebound adjuster is backed out all the way, then thread it onto the damper rod.
  8. Measure the distance between the center bolt and the lock nut.
  9. The distance should measure between 1 and 3.5mm.
  10. Engage the center bolt lock nut, and torque the center bolt to 21-foot-pounds.
  11. Apply thread lock to the center bolt, then remove the holding tool.
  12. Tighten the center bolt and torque to 41 foot-pounds.
  13. Hold your fork vertical, and measure from the tube to the axle holder.
  14. The distance should be 319mm, or 12 and 5/8ths inches.
  15. Unscrew the damper, let the outer tube slide down to the axle holder, and hang your fork by the damper.
  16. Fill your tube with 10 to 12 ounces of fork oil, depending on how soft you want your suspension.
  17. Replace the damper o-ring, thread the fork tube onto the damper for the last time, and tighten.
37 - Backout Center Bolt Lock Nut
37 – Backout Center Bolt Lock Nut
38 - Measure Center Bolt Lock Nut
38 – Measure Center Bolt Lock Nut
39 - Install Spring, Spring Seat, And Damper Unit
39 – Install Spring, Spring Seat, And Damper Unit
40 - Assemble Fork Tube And Damper
40 – Assemble Fork Tube And Damper
41 - Install Rebound Adjuster PushRod
41 – Install Rebound Adjuster PushRod
42 - Double Check Rebound Adjuster
42 – Double Check Rebound Adjuster
43 - Install Center Bolt
43 – Install Center Bolt
44 - Measure Center Bolt To Lock Nut Clearance
44 – Measure Center Bolt To Lock Nut Clearance
45 - Torque Lock Nut To 41 ft-lbs
45 – Torque Lock Nut To 41 ft-lbs
46 - Torque Center Bolt To Fork To 41 ft-lbs
46 – Torque Center Bolt To Fork To 41 ft-lbs
47 - Measure Fork Free Length
47 – Measure Fork Free Length
48 - Hang Fork By The Damper
48 – Hang Fork By The Damper
49 - Fill The Fork Tube With 10 to 12 Ounces Of Fork Fluid
49 – Fill The Fork Tube With 10 to 12 Ounces Of Fork Fluid
50 - Install The Damper O-ring
50 – Install The Damper O-ring
51 - Assemble The Fork Fork For The Last Time
51 – Assemble The Fork Fork For The Last Time

Related: How to remove and install the front wheel on your dirt bike.

Fork Installation

  1. Reset your compression and rebound adjusters to the recorded number.
  2. Install your fork just under the top fork bridge and tighten the lower pinch bolts.
  3. Firmly tighten the damper, then loosen the lower pinch bolts.
  4. Install your forks with the bottom of the damper flush with the bridge.
  5. I like my geometry slightly forward, so I typically install my forks 3 to 5 mm above the fork bridge.
  6. Torque the top pinch bolts to 15-foot-pounds, and the bottom pinch bolts to 16-foot-pounds.
52 - Install The Fork Half Way
52 – Install The Fork Half Way
53 - Tighten The Damper
53 – Tighten The Damper
54 - Measure The Fork Above Bridge
54 – Measure The Fork Above Bridge
55 - Torque Pinch Bolts To 15 ft-lbs Top And 16 ft-lbs Bottom
55 – Torque Pinch Bolts To 15 ft-lbs Top And 16 ft-lbs Bottom

If you have any questions about this fork rebuild, please let me know in the comments or on social.

Keep Your ’09-’10 CRF450r Running Right!

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