How to Inspect, Clean, and Replace Steering Head Stem Bearings


Steering head bearings are easy to overlook, until you have to replace them.  Mostly with dirt bikes the main culprit of bearing failure is lack of grease from lack of service, and corrosion because water has gotten into the bearing from power washers. The great news is that steering head bearings are easy to keep maintained, and with attention should last as long as many of us keep a bike (a few years, that is).  This article will show you how to inspect, clean, and replace if needed.

Check and grease the steering head bearings on our bikes about twice a season, which seems to be sufficient (as noted, we ride 2-4 times per month).

What you will need:

  • Wrenches and sockets
  • Steering head wrench or channel locks
  • Hammer
  • Torque Wrench
  • Waterproof grease
  • Nitrile gloves

Inspection

  • Set your bike up on a stand, and place a block of wood or something to act as a stop about 6 inches in front of the front tire.
  • Remove the bars, then loosed the bolts that hold the top triple clamps onto the forks.
  • Now loosen the steering head bolt, remove it and the washer, and set them aside. I suggest using a “steering head bolt wrench”, but you can get away with channel locks. The bolt is usually aluminum and is easily damaged.
  • Take a rubber mallet and tap on the top triple clamp on both sides to slide it up off the forks.
  • Now loosen the spindle bolt that was under the triple clamp.  When you loosen this bolt, the front wheel assembly is going to start sliding down and forward, and the block of wood you put in front of the wheel is going to keep your forks from dropping onto the garage floor.
  • With the bolt off, remove the top steering head bearing.  The other bearing is on the bottom of the steering stem, pressed onto the stem so you will not be able to slide it off.
  • Inspect both bearings for dirt, corrosion, nicks, etc.  If there is corrosion then it’s time to replace (go to the next section!)
  • If there is dirt or grime, you can clean the bearings by washing them out with solvent, but BE CAREFUL not to spin the bearings when they don’t have grease in them.  That will basically ruin them. Rinse them out with something like mineral spirits, and let them dry.  You can use an air compressor to dry them, but again be careful not to let the bearing spin.

If there is no dirt, just old grease, then you want to replenish the grease with fresh water-proof grease.

  • Place a healthy dob of grease in the palm of your hand.
  • Hold the clean bearing in your other hand, with the large diameter side facing the grease (if the bearing is a ball or non-tapered roller bearing, it can be packed from either side).
  • Draw the bearing across your palm as if you were using it to scrape the grease out of your hand, rotating it as each segment becomes fully packed.
  • When it’s done correctly you’ll see curls of fresh grease rolling out of the small end of the bearing.
  • The bearing that is stuck on the steering spindle obviously cannot be repacked this way, just get a dob of grease on your fingers, and press it into the face of the bearing, working your way all around the bearing.
  • Take a clean rag and wipe off the steering spindle, and also the inside of the frame steering head.
  • Make sure the steering head races (the surface that the bearing fits onto) are clean.
  • Before assembly I’ll put a light coat of grease on the steering spindle, just to ward off corrosion.
  • Re-insert the steering spindle/fork assembly into the frame head, taking care not to bang up the bearings.  Set the top bearing in place, drop the washer on, and put the first steering head bolt on HAND TIGHT.  Your manual will have instructions as to how tight to make this bolt, but you do NOT want to torque it down super tight.  How tight you make is based partly on personal preference as to how easily you want the bars to turn.
  • Re-assemble the rest of the triple clamp assembly as per your manual.  I always tighten the steering head bolt before I tighten the bolts that hold the triple clamps to the forks. If the triple clamps were not fully seated, and I tighten the fork bolts first, it could tweak the top triple clamp when I tighten the steering head bolt.

Replacement
Steering head bearings are not expensive, and the top one is a breeze to replace.  The bottom one is another story altogether, and of course you should replace them as a set. There are tools and methods for removing the bottom bearing, but unless you really know what your doing, you run the risk of damaging the steering stem – an expensive ‘oops.’ My suggestion is to take the forks and the bearing to a local motorcycle mechanic and let them handle it.  You’ll be glad you did.

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