2020 Fox 34 FIT 4 damper

Fox Float 34 fork FIT4 8mm shaft damper

Valving on Fox 34 FIT4 damper compression stack

Outside diameter
Face shim against LSC portion of piston (inner holes)
Second LSC shim
Clamp shims for LSC - total stack height on LSC components needs to be somewhere around 1.15mm
Face shim for HSC circuit
HSC shims
HSC shims


  • There are two versions of the FIT4 damper.  This version is the later (2020+ version) which uses an 8mm damper shaft. Earlier versions used a 10mm damper shaft.
  • Inner diameter of all shims is 9.5mm

Damper rebuild instructions

Warning!!! The Fox website has not been updated with instructions on the 2020+ FIT4 dampers for the F34 forks.  The instructions you need to use are those for the 2016-2018 36mm F-S/P-Se FIT4 3pos w/Adj Damper Cartridge Rebuild

If I enter my serial number, it properly identifies the fork as having a FIT4 damper but then lists the "Service - 2017-2023 GRIP Damper Rebuild (32mm, 34mm, and 36mm)" which is clearly not right.

Fox fork serial number search lists wrong service procedures

Damper bleeding

To bleed the damper, you need to remove the compression adjust coupler from the top of the cartridge.  It is held in place by an extremely small wire circlip which is a total PITA to get out.  You need a very sharp pick to get it out.

Fox FIT4 circlip for compression adjust coupler

Mine went flying on removal and I could not find it so I had to make a replacement.  I was able to find a suitable sized spring and cut off a portion of the first spring coil to use as a replacement circlip.

DIY replacement wire circlip from a suitable size spring

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