Uni Trak Shock Linkage Lubrication

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This service is often ignored, but is very important. The bike shown here was only 14 months old (a 2006 in 2007) with 13,700 miles. This should be done at the same time that the swingarm lubrication is performed (6000 miles), but the trained monkey was asleep at the wheel when his swingarm service was performed, so 7000 miles later here we are. If you are going to do one or the other, do the unitrak first; it sees much more of the elements than the swingarm, as the pictures below seem to show.

Tools needed:

  • Suitable jack, jack stands and/or other means of supporting the bike safely without the centerstand and with the rear wheel off the ground.
  • 12, 14, 17 and 19mm wrenches and/or sockets
  • Molybdenum disulfide grease; See this article and this one for grease type discussions.
  • O-rings. Kawasaki part #92055-1215 (size 19.8 X 2.2) Same as in the swingarm service article.
  • Kerosene or other low flashpoint solvent
  • Solvent safe container
  • Lots of towels

Caution: There are better/safer ways to do this than shown here. Use EXTREME CAUTION when supporting the bike in this manner, or serious injury could result. Ideally, someone to steady the bike would have been helpful, but 'cheap labor' was not available for this article.

Why jackstands? The bolt that holds the suspension linkage to the frame will not clear the center stand. The center stand does not need to be removed, just in the 'up' position. When it is 'down' it covers the front bolt on the linkage. If you can find a secure way to hold up the rear of the bike using the grab bar, go ahead. Using secondary support with jackstands (as described) and a jack under the engine is still highly recommended. The straps on the front are for stabilizing the bike only; don't lift it by the bars.

EX250 SuspensionMaintenance 05.jpg

Here goes:

1) Remove the mufflers (12 and 14mm nuts/bolts) and passenger footpegs.

2) Loosen all the unitrak nuts while the bike is on the sidestand. This will eliminate some of the danger in trying to break them free while the bike is precariously balanced. Use 19mm; you may need to hold the 17mm bolt head on the other side


3) Have jackstands at the ready on either side of the bike.

4) Put the bike on the centerstand.

5) Position a floor jack securely on the bottom of the engine as far back as you can get it and still get to the unitrak nuts.

6) Slowly and carefully raise the bike with the floor jack until the centerstand can be raised. Use one hand to steady the bike and the other to raise the jack. This is where a second person would be nice.

7) When the bike is high enough, while still steadying the bike with one hand, position the jackstands under the muffler brackets, making sure the rear wheel does not touch the ground while on the stands. Once the jackstands are positioned, lower the floor jack slightly, so just a teeny bit of the weight is supported by the jackstands. Those muffler brackets are reportedly made out of an aluminum/butter alloy, so don't trust them to do anything but steady the bike. The floor jack supports the weight.

TheStand.jpg TheStandStrikesBack.jpg

8) Remove the unitrak nuts (19mm x 3).

9) Support the wheel/tire with your hand and lift while removing the lower shock bolt. Ease the tire back to the ground. Once the shock is disconnected, the linkage can be moved around with ease to remove the remaining two bolts.

10) Once the linkage is removed, it is ready to be disassembled and cleaned. There are 3 shafts that go through the linkage. The shafts on each end of the linkage have a thin rubber seal (O-ring, #92055-1215) at each end, and the middle shaft has a plastic/metal seal (#92049-1109) on each end. Work each shaft back and forth gently, so as to not damage the seals, until you can slide them out of one end far enough to pull the seal out of the other side. It is recommended that you have spare seals handy before starting this, but if your bike is fairly new and you are careful, you might be okay without. All of the seals should come out with your fingernail; avoid using anything to pry at them. Just 'massage' them out.


11) The Service Manual shows an outer sleeve (bushing) around the inner sleeves you just removed, but it seems unnecessary to remove these for 'normal' service. Even with as bad as these were (you'll see) the bushing cleaned up nice and smooth, so they were left in place.

12) Once the sleeves and seals are out, it's time to start cleaning. Here is where the supply of towels and kerosene come in handy. This photo also shows the seals discussed in step 10.


13) If you neglect this service you may come across sleeves that look as bad as these. Try to replace them, but as a stop-gap measure, sand the corrosion off lightly, being sure to clean all of the grit from the sleeve when done sanding. These pictures show unserviced sleeves from a bike with 13,700 miles (service interval is 6000 miles) that saw a lot of wet weather. Avoid this result by performing this service on time.


14) Clean all of the old grease out of the unitrak linkage using kerosene soaked rags pulled through the pivot shaft holes. Keep at it until the towel comes out clean. Each of the holes has a crevice between the two halves of the outer sleeve (that we left in); try to get as much of the old grease out of there as possible.


15) Once everything is clean, take care not to let any dirt or other foreign particles get on any of the parts.

CleanGubbins.jpg TheVictims.jpg

16) Now it's time to get your fingers (or gloves) goopy. Grease up the sleeves, bolts and pivot shafts. Pack as much grease as you can into the crevices inside the holes in the linkage. There is no such thing as too much. You can wipe off the excess easier than you can put more grease in after it's assembled.

17) Insert the three clean/greased shafts into the linkage. If you are confused about what goes where, just remember that each shaft is just a teeny bit longer than the hole it goes in. Roll them around to spread the grease. If you put enough in, the sleeve should have squeezed a bit of grease out of the other end. Wipe all of this off.

18) Use the corner of a towel to clean the grease off of each end of the protruding shafts, and out of the little channel where the seal will go. The seals for the middle shaft in particular will not seat all the way unless the grease is wiped out of the channel. If you are having trouble getting the middle seals to seat, just slide the shaft halfway out so the grease under the seal can squeeze out from under the seal. Repeat for the other side. The little rubber O-rings on the end shafts will press in with your fingernail and displace any excess grease.

19) Once the linkage is reassembled, wipe any remaining grease off of all the exterior.


20) You are now ready to reassemble the bike. Reinstall everything in the reverse order of removal. For instance, the shock bolt should be the last bolt on the linkage you put on, since you will have to lift the tire again to get it seated. Install the three linkage bolts and put the nuts on them, but do not tighten all the way.

21) Put the centerstand down. MAKE SURE IT IS ALL THE WAY DOWN/FORWARD.

22) Raise the bike a smidge with the floor jack while supporting the bike with your other hand. You just need clearance to move the jackstands away from the bike. Keep a hand on the bike at all times to steady it. The bike is only supported by the floor jack and your hand at this time. Slowly lower the floor jack until the bike is sitting on the centerstand, MAKING SURE THE CENTERSTAND IS ALL THE WAY FORWARD SO IT WILL NOT COLLAPSE UNDER THE BIKE.

23) Once the bike is on the centerstand fully, remove the floor jack.

24) Tighten all the linkage nuts that you can get to to 33 ft-lbs torque. You may need to put a wrench on the bolt head to hold it. One of the nuts, and maybe more, will be blocked by the centerstand. For these, put the bike on the sidestand to finish torquing.

25) Reinstall the mufflers and passenger footpegs.

26) Clean up the mess you made, and you're done.


.....what are you still reading this for ? Go Ride !