1981 GPz550 Steering Stem Tapered Needle Bearings Source 2025?

I installed a set of All Balls Steering Stem Bearings in my GPz550 but when riding I feel movement when applying the front brake hard. Per FSM, I adjusted steering stem nut with a spanner several times over the years but the looseness persists. My winter project is to inspect and possibly correct if I assembled the All Balls Steering Stem Bearings incorrectly. While the steering stem is removed, I want a different replacement set of tapered needle bearings and races at the ready. Have great experience with Timken, I would like to install a set of Timken tapered needle bearings. Does Timken sell tapered needle bearings and races for KZ550 D1 aka GPz550?

Searching the forum threads, steell wrote in 2005  Kaw steering stem bearings chart.  he cross referenced SSK 400 fits KZ550 D1. steell stated, "this info is from a european catalogue, the bearing numbers (SSK XXX) and model names may be different in the US." Any GPz550 owners have experience with SSK 400?

I have decided not to install a new set of All Balls Steering Stem Bearings. 

TIA
Steve

All balls uses the cheapest bearing available. I believe the SSK used Nachi. I don't use these tapered bearing much because you have to compensate for the different stacked height with fork ears. In addition, you will find it really difficult to remove the lower outer race now. No room to push it out. You'll see what i'm talking about shortly. I always relieve the seat before installing these so you DO have a spot to push out if necessary.      

Doing a quick check of the OEM parts fishe shows that Kawasaki used loose ball headset bearings on those bikes...continuing many years after.  The same top bearing cone part number was used all the way to 2020.

I'm not sure what to suggest, other than maybe take things apart and see why the All Balls bearings are not working properly.  It would be nice to know what other aftermarket companies offer taper roller these days?  Trying to match up the size to general purpose bearings like Timken seems like a major longshot.

Absolutely ED! The original "individual" 1/4" balls worked just fine! One can purchase the races (4 total) for under 40usd if you shop around. The balls you can buy 100 of them for 10bucks. I'll bet since you have to keep adjusting Supertrap you didn't properly seat one or all races initially. OR, started driving them in cocked and peeled slivers from frame headstock as to prevent them from fully seating till they got knocked around from riding.  

srsupertrap wrote:

I installed a set of All Balls Steering Stem Bearings in my GPz550 but when riding I feel movement when applying the front brake hard. Per FSM, I adjusted steering stem nut with a spanner several times over the years but the looseness persists. My winter project is to inspect and possibly correct if I assembled the All Balls Steering Stem Bearings incorrectly. 

Steve I don't want to offend but which "nut" are you tightening (tapered bearings don't normally need this much maintenance) Are you adjusting the "castle nut" under the top tree then slackening the top tree clamps and pulling the tree down onto the adjusted "castle nut" so it can't back off?

Here are a couple of links from Mike Nixon regarding steering issues.

motorcycleproject.com/text/steering_bearings.html

motorcycleproject.com/text/shucking.html

asphalt900 post=919740 userid=19828All balls uses the cheapest bearing available. I believe the SSK used Nachi. I don't use these tapered bearing much because you have to compensate for the different stacked height with fork ears. In addition, you will find it really difficult to remove the lower outer race now. No room to push it out. You'll see what i'm talking about shortly. I always relieve the seat before installing these so you DO have a spot to push out if necessary. 

I appreciate your experience asphalt900 with All Balls and using SSK tapered bearings.

Q: When you installed SSK bearings in your GPz550 sounds like because the SSK bearing height, e.g. stack height is less than the OEM Bearing stack height you may have either removed some of the washers that are installed above and below the Rt & Lt fork ears? Or did you have to remove material from both the Rt Fork Cover 44033-1072 & Lt fork Cover 44033-1071 reducing the cover height in order to tighten the Steering Stem Nut?
 
 

I've never used them on a 550, only the Z1/KZ. Note the photo print of application on the SSK package. But all the aftermarket tapered bearings resulted in a slightly taller stacked height resulting in sloppy headlight ears, have to shim them Not removal of any material. But don't think your 550 has such arrangement? You might have a bracket, don't know would have to look that one up. 

Wookie58 post=919758 userid=60568

Steve I don't want to offend but which "nut" are you tightening (tapered bearings don't normally need this much maintenance) Are you adjusting the "castle nut" under the top tree then slackening the top tree clamps and pulling the tree down onto the adjusted "castle nut" so it can't back off?

Yes, I adjusted the the castle nut, e.g. steering stem nut which has the 4 rectangular slots. My adjustment process was put the GPz550 on the center stand. Place some wood blocks under the front wheel to relieve the weight. Loosen the top triple clamp pinch bolts which allows the tree and forks to move up as needed with the adjustment. Back off the castle nut CCW and then retighten the castle nut to snug. I do not think I was trying to tighten the castle nut while all the upper and lower fork pinch bolts were tight.

Critiquing my process: What I failed to do was jack the engine, remove the front wheel & brakes so I could move the forks back n forth after the adjusting the castle nut. With the wheel removed, and moving the forks back n forth you can feel play. I wish I had case guards installed which makes jacking up the engine easier. 

 

srsupertrap wrote:

Wookie58 post=919758 userid=60568

Steve I don't want to offend but which "nut" are you tightening (tapered bearings don't normally need this much maintenance) Are you adjusting the "castle nut" under the top tree then slackening the top tree clamps and pulling the tree down onto the adjusted "castle nut" so it can't back off?

Yes, I adjusted the the castle nut, e.g. steering stem nut which has the 4 rectangular slots. My adjustment process was put the GPz550 on the center stand. Place some wood blocks under the front wheel to relieve the weight. Loosen the top triple clamp pinch bolts which allows the tree and forks to move up as needed with the adjustment. Back off the castle nut CCW and then retighten the castle nut to snug. I do not think I was trying to tighten the castle nut while all the upper and lower fork pinch bolts were tight.

Critiquing my process: What I failed to do was jack the engine, remove the front wheel & brakes so I could move the forks back n forth after the adjusting the castle nut. With the wheel removed, and moving the forks back n forth you can feel play. I wish I had case guards installed which makes jacking up the engine easier. 


 

My preferred method would be to have the front wheel hanging free, then nip the castle nut while jiggling the wheel up and down until there is no play. Nip the castle nut until there is some resistance when turning the steering then back off slightly so the steering will fall to the lock stop under it's own weight. Tighten the top nut, then the clamp bolts. This should remove any play.

Another option is to keep the bike on the ground, tighten the adjustment nut while holding the front brake, and rocking the bike forwards and back, tightening until all knocking/rocking is eliminated.  Taper rollers are okay with a small amount of preload also.  At this point, there is nothing to loose if you overtighten, since you are contemplating replacing the bearings regardless.  With ball bearing steering bearings, preload is bad, but not with tapered rollers.  Just not too much.

Nessism wrote:

Another option is to keep the bike on the ground, tighten the adjustment nut while holding the front brake, and rocking the bike forwards and back, tightening until all knocking/rocking is eliminated.  Taper rollers are okay with a small amount of preload also.  At this point, there is nothing to loose if you overtighten, since you are contemplating replacing the bearings regardless.  With ball bearing steering bearings, preload is bad, but not with tapered rollers.  Just not too much.

Completely agree Ed, the only thing I would add is that the "not too much" statement is absolutely key - too much will stop the "self centring" action of the steering coming out of turns which would make for a very unpleasant ride