Öhlins TTX25 Revalve

Revalving an Öhlins TTX25 shock means replacing the low speed bleed adjuster orifice and needle and/or replacing the high speed poppet valve springs.  This procedure can be done without a complete disassembly of the shock.  With a little care the valve assemblies can be removed and reinstalled without trapping air inside the damper making the service quick and painless.  Below is an outline of our procedure for revalving an the Öhlins TTX25 using the revalve kit (U00052-01KitM).

The only special shock tools required for this service are the Öhlins gas fill needle adapter (U00050-16) and the Kaz Charge Tool.

Release Gas Charge

  1. Remove torx head screw from gas canister end cap  Pic1
  2. Apply a small amount of grease to the needle of the Öhlins gas fill needle adapter (U00050-16)
  3. Carefully pierce the bladder with the gas fill needle and thread in for stability  Pic1
  4. Depress Schrader valve core to release charge
  5. Carefully remove the gas fill needle

Prepare shock for valve assembly removal

  1. Fully open the bleed adjusters by turning them counterclockwise
  2. With no gas charge in the shock, clamp the shock in a vise with the valve adjusters up

Remove valve assemblies

  1. Screw in the high speed adjusters just enough so that there is ample room to access the circlips
  2. Clean out as much dirt and debris as possible
  3. Remove the circlips using a razor blade  Pic1
  4. Unthread the high speed adjusters to remove them  Pic1
  5. Each removed assembly will consist of the high speed adjuster housing, a spring, and a poppet  Pic1

Disassemble and reassemble valve assemblies as required

  1. Remove and replace the low speed needle o-ring.  How you do this depends on whether you have a new or old version adjuster design.
    • Old style with flat head version low speed adjuster
      • Thread the bleed adjuster so it is in the middle of its range of travel
      • Lightly clamp the hex head of the high speed housing in a vice (Clamping it tightly will deform the aluminum and ruin the adjuster)
      • Using a roll pin punch carefully tap out the roll pin
      • Fully unthread the bleed needle being careful not to lose the two small detent balls and spring
      • Remove the old o-ring and reinstall a new one from the rebuild kit
      • Thread the low speed needle with detent balls and spring back into the adjuster housing so it is again in the middle of its travel range
      • Reinstall the roll pin
    • New style with hex head version low speed adjuster
      • Thread in the bleed adjuster far enough to access the circlip
      • Remove the circlip
      • Fully unthread the bleed needle being careful not to lose the two small detent balls and spring  Pic1
      • Remove the old o-ring and reinstall a new one from the rebuild kit
      • Thread the low speed needle with detent balls and spring back into the adjuster housing
      • Reinstall the circlip
  2. Remove and replace the two o-rings on the high speed adjuster with new ones from the rebuild kit
  3. Install the desired rate valve spring and poppet onto the high speed adjuster  Pic1

Reinstall valve assemblies

  1. Fully open the bleed adjusters by turning them counterclockwise
  2. Make sure the valve adjuster housing is filled to the top with shock oil
  3. Place the adjusters into the valve ports and thread them in making sure fluid squirts out and no air is trapped underneath  Pic1
  4. Reinstall the circlips that retain the high speed adjusters  Pic1

Charge Shock

  1. If needed remove torx head screw from gas canister end cap  Pic1
  2. Apply a small amount of grease to Öhlins gas fill needle adapter (U00050-16)
  3. Carefully pierce the bladder with the gas fill needle and thread it in for stability
  4. Attach Kaz Charge Tool to Öhlins gas fill needle adapter
  5. Screw in the plunger of the no-loss air chuck on the Kaz Charge Tool which will depress the valve core of the fill adapter tying all reservoirs together  Pic1
  6. Fill the shock with nitrogen at the Schrader valve of the Kaz Charge Tool
  7. Bleed off pressure using the Schrader valve until the gauge indicates the desired pressure
  8. Back out the plunger of the no-loss air chuck on the Kaz Charge Tool which will isolate the gas reservoirs preventing nitrogen loss from the shock  Pic1
  9. Detach the Kaz Charge Tool from the Öhlins gas fill needle adapter
  10. Carefully remove the gas fill needle adapter
  11. Reinstall the torx head screw into the gas canister end cap  Pic1

Verify shock operation

  1. Check that the shock is charged and will extend on its own
  2. Check that the shock will fully extend to a firm stop
  3. Check that the shock will fully compress
  4. If the shock does not fully compress or properly extend, it is likely the floating piston is not positioned correctly, or the shock contains air and has not been properly bled
  5. Test shock in a shock dyno and verify the forces are correct, the adjusters behave properly, and there is no cavitation or excessive hysteresis
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