The Samducksa CWL-309MJ-DX-QR-ST35 Quick Release Joystick lever contains a 35A shore tension silicone grommet. Available separately for this model are two light and heavy tension grommets - the white 25 tension and red 45 tension. The lighter tension ST25 offers a similar feel to the default Sanwa JLF spring (about.5lb tension).
To replace the original SDL-301-DX grommet:
First lift the battop and shaft from the joystick body. To do this, you must remove the e-clip at bottom of the lever. A mini screwdriver wedged into the e-clip often works, pulling the clip away from the shaft. Be careful not to lose the e-clip, as it can fly off the shaft from the pressure. Lift the shaft upwards and put aside. The actuator may also loosen from the microswitches which is normal - you can put it back on when reinstalling the e-clip.
Second, remove the 4 long screws that hold the mounting plate and upper body in place. Remove the original grommet from its housing by pulling on the plastic ring with your thumb and fingers.
Now, install the new grommet by placing it in the joystick lever housing. Line up the grommet in the same orientation as the original grommet. You should see the circular rings impressions on the grommet. If you don't, you need to flip the grommet over.
Once installed, place the upper housing onto the bottom housing, and replace the long screws into the metal plate.