Check Your Swing Arm’s Linkage

Street bikes do not usually have problems with the swing arm’s linkage, but dirt bikes/off roaders, duals, enduro, and especially MX and trials racers are prone to have problems with the linkage. Dirt is the no.1 enemy and it will enter the seals and damage the linkage bearings. A direct hit on the linkage (rocks, logs, etc can cause much damage to the bearings and the arms also. Street legal bikes have better seals than racer models because it is a must to regularly service/repair full racer models. You should check your linkage regularly.

Steps

  1. Lift up the rear tire (use a jack -- it's best if the rear tire is removed).
  2. Hold the swing arm and move it upwards, downwards, and sideways. It should not shake (walang kalog). If you have doubts, dismantle the shock absorber/spring and test the swing arm again. A small bit of shake is OK and it won't kill you but if the shaking is too much, you must replace the bearings.
  3. Remove the linkage.
  4. Pry the oil/dust deals, and push the bearing out by using a press, or get a stationary vise and use wood.
  5. Look for a socket that has the nearest size to the needle bearings and pump it out by compressing the vise (just be imaginative and this will work). Fit new bearings and seals.

Tips

  • So, you don’t have the parts. Remove the linkage, but do not pry the seals. Check for damage. If there is too much rust, check if the needle bearings will move and if not, dip the linkage in a pan of kerosene and go for lunch. Check the needle bearings again when you return and try to move the needles gradually, one at a time. WD40, CRC or any deep penetrating oil will help.

Warnings

  • Be very careful not to damage the seals. If the bearing is now moving and you’ve got most of the rust, dirt, oil, crap out from the bearing, dry it and put grease (the more the merrier). Assemble the parts together and check/shake the swing arm again. There will be a bit of shake but who can complain change the bearings if you have the parts at hand but this will do for now.
  • Some swing arms will not shake and may look OK because there is just to much rust build-up in the linkage and the movement will be hard. Some bikers will only change the shocks/springs but will not check the swing arm’s condition, naturally the performance of the “new” after market spring/shock will not be used 100% because of the rusty linkage bearings that stuffs up the swing arm’s movement It is like wearing brand new shoes but without washing the feet .
  • Using pressurized steam jets to wash the linkage is really not a very good idea because water will cause the linkage bearings to rust.
  • Driving in deep water is also not a very good thing to do if you will not dismantle and do a full grease up on the linkage bearings.

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