Servicing the swingarm

From Ninja250Wiki
Jump to: navigation, search

This is an important, but often neglected, part of your bike's maintenance. One reason that this operation is so important is that Kawasaki is sometimes stingy with the grease in this area. (One member said the factory lube felt like a light coating of machine oil.) If you let it go too long, the lack of lubrication could lead to dried-out and/or rusty swingarm bearings. Poor swingarm lubrication can lead to corroded parts, excess or inconsistent rear suspension damping, limited suspension travel, and a creaking sound which is particularly pronounced mounting and dismounting the motorcycle. The service schedule specifies lubrication of the swingarm pivot every 6000 miles.

Please note: The service schedule calls for the suspension linkage lubrication to be done at the same time as the swingarm service.

Tools and supplies

  • 22, 19, 17, 14, and 12mm sockets and appropriate ratchet handle, and/or wrenches. In particular, a 19mm open-end wrench (suspension linkage 'holder wrench') and a 17mm open-end (brake torque link arm). A 12" extension and a 30" breaker bar or piece of iron pipe will make this job a lot easier.
  • Plenty of clean, lint-free rags
  • Kerosene (or low flash point solvent) and a kerosene-safe container
Kerosene is findable more easily in some places than others. Try a mom & pop hardware store or the camping section at Big Box, Inc. Or you can use one of the many alternatives: automotive parts cleaner, carb cleaner, mineral spirits, lacquer thinner, WD-40, electrical contact cleaner, diesel (stinky) or Simple Green.
  • Molybdenum disulphide ("moly") grease - Any high-pressure bearing grease will do. However, a waterproof lithium grease containing molybdenum disulphide is the best choice. The factory explicitly calls for molybdenum disulphide, as it is an extremely effective additive for needle bearings in oscillating applications. It reduces wear by plating the bearing needles.
This grease is an excellent choice; it is a lithium soap and contains molybdenum disulphide:
Grease2.jpg Grease.jpg
  • O-rings. Kawasaki part #92055-1215 (size 19.8 X 2.2) The Unitrak linkage uses a LOT of O-rings around the bushings, and it isn't that unusual to find some damaged ones on a high-miles bike. It is imperative that these O-rings are in good shape. You normally don't need any, but stalling the job for 3-4 days because you're missing a $2 part would be bad.

Procedure

Make sure you use cheap labor as much as possible. Why should you get your hands any dirtier? They may even appreciate the bonding experience... in 15 or 20 years. If cheap labour is unavailable, blue nitrile gloves make an excellent alternative.

Mywrencher.jpg

1) Remove the muffler(s) using a 12mm (header pipe) and 14mm socket (footpeg bracket). You may need to "rotate" the muffler to get it off the header. While it is off, you can clean the chain lube off the header and muffler.

Note: The factory suggests you remove both mufflers. It is only necessary to remove the left one.

Withoutmuffler.jpg Withoutmuffler2.jpg

2) Remove the upper chain guard (warning: soft bolts) and rear wheel. Make sure to tie your brake caliper out of the way and ensure there is no pressure on the hydraulic brake line. One way to keep it out of the way is to slide a long extension (or piece of threaded rod) through it and hang it through the passenger peg brackets. Make sure your chain will not lie in the dirt. (A big piece of cardboard works well here.)

Brakeremoved.jpg Wheelremoved.jpg

3) Remove the nuts from the swingarm pivot (22mm), lower shock mount (19mm) and upper tie rod arms (19mm), but do not remove the bolts or pivot shaft. The easiest way to remove the 19mm nuts is to "lock" them in place with a 19mm open-end wrench, then spin their corresponding bolt heads with a 17mm socket, extension, and breaker bar (or ratchet + piece of pipe).

Swingarmclose.jpg Pivotnutremoved.jpg

4) Slide something under the swingarm to hold it up (like a milk crate) and remove the lower shock bolt and upper tie rod bolts.

5) Remove the swingarm pivot shaft. This comes out just like a wheel axle. An easy way to get this out is to tap it out with a long extension and rubber mallet, or a piece of 2x4. When the pivot comes out, the extension will be in, providing support for the swingarm. Now remove the extension.

Alternatively, you can support the swingarm with your hand while removing the pivot shaft. Push the shaft through from the left first, then run around the bike and grab the shaft and pull from the right. There is some stress on the bike at this point, so please don't put a finger inside the swingarm pivot.

6) Untangle the swingarm from the chain and shock by pulling back on the swingarm until the bottom of the shock clears the cross brace. Then, rotate the swingarm to the right to unhook the chain and remove it. Be sure your brake lines are disconnected from the swingarm.

Swingarmoff.jpg

Remove the rubber chain guard from the swingarm. Wipe off any crud from it and the swingarm. If you are planning to re-paint the swingarm when you see how horrible it looks, Duplicolor silver wheel paint, available at fine Wal-Mart stores everywhere, is a perfect match.

7) Remove the plastic rings from either end of the pivot shaft sleeve and clean them. They pop out easily with your fingernails.

8) Remove the pivot shaft sleeve from the front of the swingarm by sliding it out one end.

9) Wash the pivot shaft, pivot shaft sleeve, and needle bearings with kerosene and dry thoroughly.

Cleanparts.jpg

10) Try to wipe as much old grease out of the front of the swingarm as you can. You can use a wooden dowel rod with a kerosene-soaked rag and push it through the front of the swingarm a few times to get most of the grease. Then use a kerosene-soaked rag on a finger to clean the bearings in place. Ideally, the bearings should be pressed out, cleaned, and pressed back in, but the risk of damaging the bearings is likely the greater of two evils.

Dirtyneedlebearings.jpg Cleanishneedlebearings.jpg

11) After all parts are dry, inspect for wear or damage. Minor wear signs are normal, but discoloration of the shaft or bearings is not. The discoloration below isn't a problem - it's an indicator. You have too much heat because you have too little lube.

000 0334.jpg

If you have rust, such as in these photos, you have a problem. For very light surface rust, or if you are really cheap and not particularly concerned with your safety, you can sand down the shaft and hope for the best. The real answer is to replace the rusty parts. You can probably find them on eBay, or in a motorcycle wrecking yard. The parts can also be purchased new from the usual sources.

000 0333.jpg 000 0330.jpg

Note: The rusty parts shown above are from a bike with only 15,000 miles on it. The pivot shaft shown below was from a five year-old bike with only 5000 miles.

Swarmpivot3.jpg

12) If bearings, sleeve, or shaft need replacing, replace the bearings and sleeve as a unit.

13) If everything is okay, pack the bearings with moly grease with your finger. Use lots of grease; there is plenty of room inside the swingarm. Lightly grease the pivot sleeve and reinstall it through the bearings. Reinstall the plastic rings after wiping any crud off of them.

14) Reinstall the swingarm by supporting the swingarm with one hand and feeding the pivot shaft through from the right side of the bike. Be sure the rubber chain guard is on the swingarm before doing this. Also make sure the chain is installed. Those two things are easily forgotten and are a major time-suck to take apart again if you forget. Put the nut on the swingarm shaft a few turns, but do not tighten.

15) Install the upper tie rod and lower shock bolts. Put the nuts on them, but do not tighten. Be sure the bolts are installed in the same direction as they came off. There is a lip on the swingarm mounting point to keep the nut from turning on the upper tie rod bolt, which can't do its job if the nut is on the other side. This lip will not hold the bolt head, so you will know if you have the bolt in backwards.

16) Tighten the pivot shaft nut to 65 ft-lbs/88 N-m. Tighten the lower shock bolt and tie rod bolts to 33 ft-lbs/44 N-m.

17) Reinstall the rear wheel, being sure to align the sprockets, adjust the chain slack and torque all fasteners to the proper specs. You might as well clean and lube the chain while you're there, too.

18) Reinstall the mufflers.

19) Test ride with a smile of satisfaction.