tech tip "chain adjuster maintainence"


Pete Payne

MX-Tech Suspension Agent
Nov 3, 2000
933
38
This is one area of the bikes that I see is neglected, the chain adjusters. Recently I have had several come through the shop that are froze/rusted and will not turn. These need to be took oput frequently and lubed, preferably with anti-seize. This will help keep these working properly. On some bikes such as the Yamaha's , the swing arm will take on water and dirt from thje hole near the front of the swingarm that is there to access one of the linkage bolts. If memory serves me right , the right side is not blocked off and water etc. can go down the swing arm and start to rust the end of the chain adjuster bolt . Also the yamaha's have a hole drilled on the bottom side of the swing arm at the back to allow water etc. to drain out of the swing arm. This hole needs to be kept open. I have also seen other bikes (KTM) have water drain out of the adj. bolt hole once the bolt is took out to be lubed. This bike's swing arm does not have any holes in it to access anything (linkless suspension) and still there was water in the swing arm and the bolts were rusting to the point tht they were going to rust shut and would not turn.

It just takes a little time to save alot of agrivation and will keep you from taking the swing arm to a machine shop to have the bolts drilled out from rusting shut. The bolts are in an awkward spot to be drilled out and requires a drill bit that is longer than standard issue.
 

rickyd

Hot Sauce
Oct 28, 2001
3,447
0
Great tip!!
Had a adjuster bolt break due too rusting.. Caused a bent axle and a pain too get out of the swingarm..
Thanks for the tip..
Rick
 

Smit-Dog

Mi. Trail Riders
LIFETIME SPONSOR
Oct 28, 2001
4,704
0
How about using some silicone sealant to plug up all the holes (where possible). Even mounting holes, i.e. brake hose support - calk the threaded holes.
 

Jaybird

Apprentice Goon
LIFETIME SPONSOR
Mar 16, 2001
6,452
0
Charlestown, IN
Not only is water a problem for corrosion on adjuster bolts, they can also experience galvanic corrosion. This occurs when two dissimilar type of metals are in contact with one another in the presence of moisture. An electrical process takes place and causes the less noble of the two metals to corrode.
The easy answer to this is to coat the fastners with anti-seize, as Pete has explained. But shop for anti-seize and you will find a plethora of different brands with as many types of make-ups.
With regular maintenance you can probably chose any of the anti-seize compounds available and do fine.

However, by simply coating the bolt threads with a wateproof grease may have you thinking the threads are protected, but they may not be for an extended amount of time.
Grease, in simple terms is oil that is whipped up in with soap base such as lithium, to provide a less fluid lubricant that will stay in place much better than the raw oil would. Lubrication and corrosion protection from grease depends on the oil seperating from the soap base and coating the surfaces.
When we paint on a grease, there will come a time when the finite amount of oil will have seperated, or left the soap base and is no longer present. The remaining soap base is not a good protector against corrosion. In some cases, as in that of grease that is made with a calcium base, the remaining base soap can actually harden up like concrete. Not a good situation.

Many anti-seize compounds, as well as many greases, contain molybdenum, or "moly". The molecular structure of moly works quite a bit differently than plain petroleum oil does. Moly is a polar solid, meaning it is like little molecular magnets that adhere themselves to the oxide layer of the metals surface. They will fill in all the microscopic craters and valleys that are present in all metal surfaces. Even when the base oil has left the carrier (soap), moly will still remain providing continued protection of both the bolt and the reciever threads.

If you are going to coat your adjuster threads with grease, or with anti-seize compounds, regular maintenance will mean you will probably be fine no matter the choice of product. However, if you feel you may take an extended amount of time before you address your adjuster bolts, you should use a grease or compound that contains molybdenum.
 

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