This How to article will be in two parts.
Part 1. How to clean and inspect shock arm linkage bearings.
Part 2. How to replace shock arm linkage bearings.
One of the most overlooked area's of most dirt bikes is the linkage bearings and swing arm bearings.
Why?
Probably because they aren't the easiest to get to and many people simply don't even bother with them.
Older bikes use to have Zerk fittings but few if any of the new bikes do.
For some reason the manufactures have decided to vastly reduce the amount of grease they put in their bearings.
It almost appears that they use the grease that comes on the bearings but do not add any of their own.
I have seen some bikes only a year old with ruined linkage bearings.
So just a thought for all you new bike owners, GREASE your bearings before it's too late.
Often we buy bikes that are in otherwise excellent condition.
Upon disassembly and inspection we see that the linkage bearings and swing arm bearings have been completely neglected and are rusty or completely broken apart.
Even one of our sponsored riders had his linkage bearings and swing arm bearing completely worn out.
It was so bad that we couldn't correctly set his sag.
No wonder he had so many problems with correct steering, jumping, and whoops.
I was following behind him on a single track woods ride and noticed that as we went over the jumps his suspension did not seem to to travel any where near it's limit.
Once we stopped I had him get off the bike and compressed the suspension.
It went down ok but it was very slow coming back up.
In this article I will show you how to inspect and grease your bearings.
In this example we are using a shock arm linkage from a 2000 Kawasaki KX500.
Here is the setup:
As you can see, it is a little dirty, one of the bearings is shot, and one of the arms is very worn.
No question there, replace that arm.
One of the first things we do is clean the parts externally BEFORE we take it all apart.
Why?
If your bearings are good, you want to minimize the chance of contaminating the bearings with dirt, sand, or other debris.
If the part is clean before hand you greatly reduce that chance.
Here is the assembly after it was disassembled:
One of the first indicators if the bearings are good or bad is how hard the sleeves are to pull out from the bearing.
If they are stuck or hard to get out most likely you will need to replace them.
If the sleeves pull out fairly easy take a look at the surface of the sleeves.
Are they very smooth or are they pitted or rusty?
In this example the sleeves look good after wiping them off with some WD-40 as a cleaner (Not a lubricant).
To get these bearings ultra clean you can remove the seals, put the bearings into a can of diesel or kerosene, scrub them with a nylon brush (Your wife's tooth brush) let the reader use discretion
Once they are clean, put your finger inside the bearing and see if the individual needles spin.
Also, spin the bearings around and see if it is smooth.
This pic was taken after the bearings were cleaned:
In the picture you can see that the bearings are clean and ready for grease.
If it feels gritty clean again.
If it still feels gritty you will need to decide if you need bearings.
If you plan on keeping the bike in excellent condition, replace the bearings.
If they are smooth or you do not plan on replacing them right away go ahead and use a good quality grease and grease the bearings liberally.
Note: Consult your manual to see grease recommendations for your specific bike.
Be sure to spin the bearings and roll the grease into the bearings.
Once this is done and the rest of the parts have been cleaned, go ahead and reassemble one of the sleeves with the seals.
Spin the sleeve around to make sure it is very smooth.
There should be no up or down play, only side to side.
BE SURE TO CONSULT YOUR MANUAL FOR THE CORRECT TORQUE SPECS.
If it still spins smooth you can reassemble the rest and you are ready for a ride.
If any of the bearings feel gritty I recommend that you replace them while you have it all apart.
Minus the bearing and the arm this unit is ready to install.
Remember, this information is provided free of charge and is not intended as a replacement for the directions in your manual.
ALWAYS consult your manual before you start a job like this.
Any questions?
Feel free to join in with your thoughts.