Steering head bearing replacement
How to tell if your bearings need looking at
It takes a huge problem to feel anything while riding, so to check your bearings you need to get the front wheel in the air. Turn the bars from side to side with the wheel off the ground and feel for any slight notches. There should be no hesitation when turning the bars from side to side. If there's even the slightest notch or hesitation, they need greasing (at least).
To check for proper steering head tightness: With the wheel still in the air, grab the black part of the forks near the wheel (lower fork legs). Try to move them forward and backward. They should not move. If you have movement, chances are the steering head bearings are loose and need to be adjusted, and probably greased.
If you think there is a problem after you do the testing, you're going to have to take apart the front of your bike to get at the bearings. If they feel pretty bad, you might want to order parts before you do this.
If you just want to lube the bearings, the directions are basically the same, except for removing & replacing the bearings and races.
If all you're doing is adjusting the stem nut, you don't have to actually remove the upper triple. The adjusting nut will turn fairly easily once the clamping pressure is removed by loosening the stem head bolt.
If your races are notched, dented, or otherwise not smooth inside, you should replace them. Check to see that the bearings are in good shape and not pitted. If they just need to be lubed, lube them up and put everything back together.
Diagram and explanation
This is what the steering head of your bike looks like when you take it apart:
"Lock nut" is a bit of a confusing name (though that's what Kawasaki calls it). It's really the adjustment nut for the preload (pressure) on the bearings. It doesn't really lock anything, since it's not really tight. We'll call it the 'stem nut' from here forward. The stem head bolt clamps the upper triple tree against the stem nut to hold the adjustment.
If you want to replace the bearings with OEM parts, you need to get everything circled in these diagrams:
From FRAME diagram (left):
From FRONT FORK diagram (right):
Aftermarket roller bearings
You can also get tapered roller bearings from All Balls. Order them directly or check with a shop that sells from the Parts Unlimited or Tucker Rocky catalogs. These will last longer and require less maintenance. They will raise your bars 1/8-1/4", which is not something you're going to notice.
The part number for the All Balls kit is 22-1014, and this kit contains the following:
This kit contains a seal for the top bearing, which is not an OEM part and was not put on bikes from the factory. The seal fits fine, however, and helps keep dust and grime out and lubrication in.
Stuff that has to be removed
You're going to have to remove most everything on the front end of the bike. Removing the tank is optional, but a really good idea. As you did while testing, find a good method of propping the front end. Make sure it is all stable and not going anywhere.
It is highly recommended to loosen the stem head bolt (and other bolts) while the front of the bike is still on the ground. Turn the bars to their lock to the left. It will likely take a lot of force to loosen this bolt. A regular short ratchet will probably not work. Try a breaker bar with a length of pipe as an extension.
These things need to be removed:
Remove the stem head bolt that you already loosened. The top triple tree should come off now and reveal the stem nut itself. To remove the nut, use a spanner such as the kind used to adjust shock preload. An adjustable spanner like the one on the right should be usable for other tasks.
The alternative, and definitely not the right tool for the job, is to get a punch with a 90 degree nose or a #3 flat-tip screwdriver and carefully hammer the nut until it's loose. It's much harder to get the adjustment right at the end with this method, and it also provides more opportunities to slip and damage something (like your hand). A pipe wrench will also work for this (YMMV).
Removing the old bearings
Once the nut is removed, remove the dust cover, the upper bearing race, and all the ball bearings. Keep it all, in case it can be reused. Watch for balls rolling around your workspace. Put a box under the steering head to catch the ball bearings when they fall out.
Slide the triple tree down and remove the lower race and balls. Be prepared for the bearings to fall out of their own accord. Inspect these and set them aside for now. There are 20 ball bearings in the lower race and 19 in the upper. It's fairly obvious if you are missing some (which is quite likely, since they love to run and hide).
You now need to knock out the races that are stuck in the frame. Use a piece of steel rod and a hammer to push out each race. Just set it against the race in a different place for each whack of the hammer. Be especially careful not to knock the bike over when hitting upwards.
Other ways you might think about for this include using a bearing puller, a piece of PVC pipe in the correct size, or a punch.
Don't worry about damaging the races; they're going to be replaced. Clean the places that hold the races on the frame with a rag, getting out all the dirt and grime.
Removing the race that's stuck on the lower triple tree can be a bit harder. The steering tube and lower triple are all one piece. Clamp the tube that goes between the two triples (henceforth know as the 'steering tube') in a vice. Vice scuffs on that tube will not affect anything, as it doesn't come into contact with anything except at the ends through the bearings. There's a large enough gap between the outside of that tube and the inside of the steering head so burrs on the tube from the vice will not matter. So, turn the part upside down so it looks like a 'T', with the lower triple on top, then clamp the vertical portion of the 'T' in the vice.
Use the same punch method as you did above. Hammer with the metal rod through the bottom of the triple, then slide the race off down the steering tube. Don't worry about damaging the seal or washer, as they will also be replaced. Clean everything that will be reused.
Installing the new bearings
Bearings in the steering head
You might consider putting the races in the freezer overnight. This should shrink them a little and make them easier to put on.
Take the larger bearing race (#99-3503) and install it on the lower part of the frame's steering head. To do this, get a piece of pipe that's a teensy bit smaller on the outside diameter than the race, but large enough so it cannot slip into the bearing surface of the race. You want to apply pressure all around the edge of the race without touching the inside of it. You can also use a socket of just the right size.
PVC is safest for not damaging the metal, but it is harder to find the correct size. Take the bearing to a hardware store and try to find the correct size. PVC is the first choice; a socket or metal pipe is second.
If the part of the pipe you are hitting is wider than the hammer, put a flat piece of metal across the pipe, so the hammer blows are transmitted to all edges of the pipe equally (or use a wider hammer).
Be very careful to hit only the outside of the race. Even just a light tap on the inside of the race could ruin it.
Install the top race (#99-3504) in the steering head in the same way.
Don't install the races upside down. This is impossible with oem parts and should be apparent with the tapered bearings. These diagrams show the taper of the bearing and race. The race fits into the stem (frame), and then the bearing fits into the race.
Top bearing/race orientation:
\ / bearing
|\ /| race
Bottom bearing/race orientation:
|/ \| race
/ \ bearing
Installing the larger (#99-3503) bearing onto the lower triple tree can be fairly difficult. If you have a hydraulic press and some PVC tubing, use that. If not, use a hammer and something hard to hold the clamps against. Place the bottom of the triple clamps so they are completely flat. Any angle in them and you'll bend them - which means you will need a new triple.
First, slide the larger seal (#33-1006) down, with the metal side facing downwards. Now slide the bearing down the tube as far as you can, with the taper going up (looks like this / \ ).
Put on the old race, turned upside down to give the tubing more lip to bite onto. Only put pressure on the very inner (solid metal) portion of the bearing. Your pipe should only be large enough to slide over the stem tube and contact the inner ring, not the bearing rollers. In the below pictures, you can see a thin circle of metal closest to the tube. Press on that.
Hydraulic press method
Shown below is the lower triple with the steering tube attached. This is the fancy way of doing it, with a piece of black PVC over the tube so the press is pushing only on the bearing via the PVC pipe.
Be careful when you apply pressure. Do so slowly, and be ready for loud "pop" sounds as it goes on. Release the pressure once or twice to visually inspect for crookedness and make sure it's seating properly.
Lube everything up liberally, making sure you work the grease into the bearings well. Spin them several times and then re-apply to ensure it's getting deep into them. Put an extra bead just above the bottom bearing, as it will get forced down into the bearing when you install the forks and the bearings seat the grease in properly. Do the same for the races.
Slide the triple tree up into the frame. Take the upper bearing (#99-3504) that you already worked grease into and slide it, small end down, onto the tube (looks this \ / ). You will note this seems to stick up a bit - it does - and your bars will be a bit higher than before. Take the smaller seal (#33-1005-1) and place it, metal side up, onto the bearing. It should almost 'click' on, and on top of this you will place the dust cover and then the stem nut.
Tighten the stem nut up VERY tight, as hard as you think you can and still get it off. You are trying to seat the bearings, and you want maximum compression on all the bearings. Loosen it off until you can turn the triple tree freely.
If you're using OEM bearings, torque the stem nut once to 14 ft-lbs to seat the bearings, then back it off so there is no preload.
Now you have to adjust the tightness of the stem nut. Tighten the nut until it gets a bit of resistance, then back off a tad. You want it tight enough so the bars turn freely lock-to-lock with just a push of your hand (front end is still in the air). No tighter, no looser. Torque the stem head bolt to 35 ft-lbs.
Reassemble the front end, putting everything back on that you took off. Tighten up the fender, but leave the other nuts loose. Align the forks, then tighten everything to spec. Reassemble the horn, fairings, and gas tank. Put the bike on its centerstand. Turn the bars left and right, feeling for any notches or excess of friction. If there is too much, readjust the tightness of the stem nut.
Go for a very quick test ride, then check the torque on everything again. Recheck the stem head bolt torque after riding for a week or two, to make sure it hasn't settled and become loose.