Improved O-rings For Scotts Steering Stabilizer Damper Rebuild Repair Kit

Tools and Materials Needed

• Damper Oil: Bel-Ray HVI Light, Spectro Very Light, PJ1 2.5wt, or equivalent (3wt hydraulic oil, ~100ml). Do not use motor oil.
• Tools: Metric Allen wrenches (for 4x10 and 4x12 socket screws), torque wrench, flathead screwdriver, syringe or tapered-tip oil bottle (Scotts-specific recommended), pliers, clean rags, contact cleaner or brake cleaner, air compressor (optional for drying).
• Other: Drain pan, gloves, safety glasses, Scotts service manual (downloadable from scottsonline.com).
• Optional: Scotts link arm removal tool and seal replacement tool for easier servicing.

Step-by-Step Rebuild Instructions

1. Safety Precautions
• Park the vehicle or motorcycle on a flat surface, engage the parking brake, and disconnect the battery to prevent electrical issues.
• Work in a clean, well-lit area to avoid losing small parts or introducing debris.
• Wear gloves and safety glasses to protect against oil and sharp components.
2. Remove the Stabilizer
• Detach the stabilizer from the vehicle. For motorcycles, remove the link arm and tower pin using appropriate tools (e.g., 6x20 socket cap screws).
• Clean the exterior with contact cleaner to prevent dirt from entering during disassembly.
3. Disassemble the Stabilizer
• Remove Top Cover: Using a metric Allen wrench, remove the ten bolts from the top housing cover.  Twist the cover sideways to detach. Place a drain pan underneath to catch oil.
• Drain Old Oil: Remove the top cap O-ring  and dump the old oil into the drain pan. The oil may appear dirty due to metal wear or breakdown.
• Remove Internal Components:
• Carefully extract the main wing assembly and main seals.
• Remove the base valve assembly and its O-ring.
• Unscrew the sweep control assemblies and their O-rings.
• Remove the high-speed valve assembly and its O-ring.
• Remove the bottom bleed hole screws (4x6 socket flathead) and O-rings.
• If servicing the knob, remove the set screw, spring , steel ball , and brass knob O-ring.
• Caution: Handle internal components carefully to avoid damaging the main wing or valve assemblies. If parts like the shear pin or main housing  are worn, they may need replacement (additional cost).
4. Clean Components
• Clean all parts with contact cleaner or brake cleaner to remove old oil and debris. Focus on the O-ring grooves, main wing, and valve assemblies.
• If available, use an air compressor to blow-dry components to ensure no residue remains.
• Inspect the main seals, shear pin, and wing assembly for wear or damage. Replace if necessary.
5. Replace O-Rings and Seals
• Install new O-rings from the rebuild kit:
• Top cap-to-body O-ring (#0338-55): Lubricate lightly with damper oil and seat in the top cover groove.
• Main seals (#1027-02, x2): Place in the main wing assembly, ensuring proper alignment.
• Base valve needle O-ring (#0338-14): Install on the base valve (#4003-01 or #4003-02).
• Sweep control O-ring (#0338-58 or #0338-58-SD): Fit onto each sweep control assembly.
• High-speed valve O-ring (#0338-59): Install on the high-speed valve (#4005-01 or #4005-02).
• Bottom bleed hole O-rings (#0338-56, x2): Place in the bleed hole recesses.
• Knob-to-base valve O-ring (#0338-57): Install if servicing the brass knob (#4016-01).
• Use a small amount of damper oil to lubricate O-rings for easier installation and to prevent twisting. Ensure all O-rings seat properly without pinching.
6. Reassemble the Stabilizer
• Reinstall the main wing assembly, base valve, sweep controls, and high-speed valve into the main housing (#4002-01 or SD-specific).
• Partially fill the housing with damper oil (Bel-Ray HVI Light or equivalent) before reattaching the top cover to simplify bleeding.
• Grease the top cap O-ring and carefully press the top cover onto the housing, ensuring the seal remains seated. Tighten the ten bolts (4x12 and 4x10) to Scotts’ torque specs (consult service manual, typically 2-3 Nm).
• Reinstall the bottom bleed hole screws with their O-rings.
7. Fill and Bleed the Stabilizer
• Flip the stabilizer over to access the bottom bleed holes.
• Remove one bleed screw (#0382-05) and move the main wing fully to one side using the link arm.
• Using a syringe or Scotts tapered-tip oil bottle, inject damper oil into the opposite bleed hole to push out air. Fill until oil flows consistently without bubbles.
• Reinstall the bleed screw, then move the wing back and forth slowly to check for trapped air. Repeat the process if air remains, removing one screw at a time and injecting more oil.
• Leave a small air bubble to allow for oil expansion during heating, as recommended by Scotts.
• Tighten both bleed screws securely.
8. Test the Stabilizer
• Manually move the wing back and forth to ensure smooth damping with consistent resistance. If it feels sloppy or has no resistance, re-bleed the system.
• Reinstall the stabilizer on the vehicle, reconnecting the link arm and tower pin. Tighten all bolts to manufacturer specs (e.g., 6x20 screws to ~10 Nm).
• Test-ride the vehicle or motorcycle, checking for proper damping, no leaks, and smooth steering. Resistance should be adjustable via the knob and sweep controls.
9. Final Checks
• Inspect for oil leaks around the top cover, base valve, and bleed holes after a short ride.
• Verify the stabilizer provides consistent damping and doesn’t “let go” prematurely, which could indicate air in the system or worn internal components.
• Clean up any spilled oil and dispose of old oil properly.

Tips and Warnings

• Service Interval: Change the oil every 10-20 hours of heavy use (e.g., off-road riding) and replace seals every few oil changes to prevent leaks.
• Precision Required: Be cautious during disassembly, as internal components like the main wing or shear pin can be damaged. If unsure, send the unit to Scotts or an authorized service center like BRP ($75 basic service).
• Oil Type: Use only 3wt hydraulic oil (e.g., Bel-Ray HVI Light). Incorrect oil can degrade performance or damage seals.
• Ohlins/SD Compatibility: The Scotts rebuild kit is compatible with Ohlins/SD-style dampers, as they share the same design. Confirm part numbers for SD-specific components (e.g., top housing or sweep control).
• Cost Savings: A rebuild kit  is significantly cheaper than a new stabilizer ($400+) or professional service (~$75+).
• Video Resources: Watch “Scotts Steering Stabilizer Detailed Service” or “Scotts Damper Quick Oil Change” on YouTube for visual guidance.

Troubleshooting

• No Damping: Likely due to air in the system or worn internal components (e.g., main wing or shear pin). Re-bleed thoroughly or inspect for damage.
• Leaks: Check O-ring seating, surface cleanliness, and bolt torque. Replace damaged main seals or top cover.
• Sticky Operation: Contaminated oil or damaged seals may cause this. Clean thoroughly and replace all O-rings.

Persistent Issues: If rebuilding doesn’t restore performance, send the unit to Scotts or BRP for inspection of internal parts like the shaft or housing.