I'm now in the habit of putting my thoughts down on procedures that might occur years apart. I had to consult the manual and read and reread the instructions on fork oil before it became clear. Also, there were gotchas. I'm going to assume the reader is a decent home mechanic and leave out bike jacking, wheel and fork removal procedures. These notes would supplement a thorough read of the Suzuki or other manual. Note also these instructions were revised on 10.4.22 to say the long thin rod that fits inside the "inner rod" is removed when setting fork level.
Fork oil replacement - notes from 10.2.22
1. Forks still on bike - loosen fork cap slightly
2. Remove forks from bike
3. Separate top cap from cartridge unit. Use a 14mm wrench to turn the preload adjuster in the opposite direction of nut #17 on the Suzuki parts diagram. Once nut #17 is released the top cap spins off and separates from the rest of the assembly.
4. Now remove the "spring guide" that sits at top of the white plastic spacer, the plastic spacer and the main spring. Also, remove the long thin rod from the body of the "cylinder" aka part #13". That thin inner rod displaces just about 3mm of fluid height. Don't ask me how I found that out. When setting oil level, everything else stays in the fork body. Another way to look at it is everything loose comes out when setting fork oil level. What remains is held in by the bolt at the bottom of the fork.
5. Dump the old oil. Optional - consider a method of more thoroughly cleaning the assembly internals by removing the bottom bolt. Note an air ratchet is sometimes necessary for that and thread locker is called for upon reassembly. Bottom bolt removal is not necessary for a routine fork oil change.
6. With the "inner tube aka part #12" all the way down in the "main body aka part #4", add roughly 450ml of oil.
7. With fingers, pull the "cylinder aka part #13" 5 inches up and down slowly 10 times. Wait 6 – 8 minutes more until all bubbles are gone. Recheck for bubbles by slowly pulling the cylinder up a few inches and pushing it back down slowly. If no bubbles then proceed.
8. Check oil level with a straight coat hanger section marked with white electrical tape or other nonabsorbent tape. It’s easy to dip and view the oil level on the nonabsorbent tape. Add oil a bit at a time until 162mm from top.
9. Insert spring
10. Reach through spring and pull cartridge aka part #13 upwards with long tape covered needle nose pliers.
11. Insert the long thin rod inside the cylinder. Interestingly there is no separate part number for that rod in the diagrams. It's considered to be part of part #13 even though removable.
12. Insert white spacer and locator over the cylinder aka part #13.
13. Make sure you set the height of nut #17 at 11mm from the top of the threaded section as per Suzuki.
14. Screw the fork cap onto the cartridge taking care not to rotate nut #17. (reverse of step 3) and then onto the fork body.
Fork oil replacement - notes from 10.2.22
1. Forks still on bike - loosen fork cap slightly
2. Remove forks from bike
3. Separate top cap from cartridge unit. Use a 14mm wrench to turn the preload adjuster in the opposite direction of nut #17 on the Suzuki parts diagram. Once nut #17 is released the top cap spins off and separates from the rest of the assembly.
4. Now remove the "spring guide" that sits at top of the white plastic spacer, the plastic spacer and the main spring. Also, remove the long thin rod from the body of the "cylinder" aka part #13". That thin inner rod displaces just about 3mm of fluid height. Don't ask me how I found that out. When setting oil level, everything else stays in the fork body. Another way to look at it is everything loose comes out when setting fork oil level. What remains is held in by the bolt at the bottom of the fork.
5. Dump the old oil. Optional - consider a method of more thoroughly cleaning the assembly internals by removing the bottom bolt. Note an air ratchet is sometimes necessary for that and thread locker is called for upon reassembly. Bottom bolt removal is not necessary for a routine fork oil change.
6. With the "inner tube aka part #12" all the way down in the "main body aka part #4", add roughly 450ml of oil.
7. With fingers, pull the "cylinder aka part #13" 5 inches up and down slowly 10 times. Wait 6 – 8 minutes more until all bubbles are gone. Recheck for bubbles by slowly pulling the cylinder up a few inches and pushing it back down slowly. If no bubbles then proceed.
8. Check oil level with a straight coat hanger section marked with white electrical tape or other nonabsorbent tape. It’s easy to dip and view the oil level on the nonabsorbent tape. Add oil a bit at a time until 162mm from top.
9. Insert spring
10. Reach through spring and pull cartridge aka part #13 upwards with long tape covered needle nose pliers.
11. Insert the long thin rod inside the cylinder. Interestingly there is no separate part number for that rod in the diagrams. It's considered to be part of part #13 even though removable.
12. Insert white spacer and locator over the cylinder aka part #13.
13. Make sure you set the height of nut #17 at 11mm from the top of the threaded section as per Suzuki.
14. Screw the fork cap onto the cartridge taking care not to rotate nut #17. (reverse of step 3) and then onto the fork body.
