Wednesday, April 15, 2015

Beware of a squeaking Yamaha...

The rear suspension of the Yamaha had squeaked a little from day one. Yamaha had diagnosed it as the swingarm seals and said it was nothing to worry about, ‘they all do that sir’. Some days it was hardly there while on others you could hear it quite clearly. Gradually it had become, at times, louder. Embarrassing even. We actually thought it was the rear shock absorber… it wasn’t… it was far worse than that.

If only Yamaha had fitted grease nipples...
With the shock and the links removed, the squeaking was still there, and just as loud too. Upon removing the swingarm, I couldn’t find anything wrong with the seals which were the culprit according to Yamaha. Trying to rotate the spacers in the swingarm bearings made clear where the problem was. I could hardly rotate them at all! But when they did rotate, the sound was horrible. 

Rust is a continuous problem on
the XT too...
The repair manual simply states 'pull out the spacers'… I needed a press to do that as the whole lot inside had seized. When they eventually did come out I found a wrecked spacer and a rusty mess that once was a needle bearing. The spacers had the needle rollers engraved in them, the swing arm was rusted on the inside where the bearings reside too. It was obvious they had been assembled with hardly any (if any at all…) grease. What a mess! 

For some incomprehensible reason the OTR swingarm overhaul kit only contains the needle bearings but not the spacers. The Wemoto kit is incomplete as well, while Kedo doesn't list them at all. As the spacers are an integral part of the bearing assembly, they should be included in a rebuilt kit. In fact the only one I could find that list them is Yamaha. I could foresee some fitment issues when ordering half a bearing from manufacturer A while ordering the other half from B. Therefore decided to get original Yamaha parts and said goodbye to a tonne of money... 

Removing old and, in this case, fitting new swing arm bearings with the aid of the swingarm pivot bolt and spacers as a press, rather than using a hammer
Moving parts will eventually wear out of course, especially when they aren't lubricated. Yamaha states that to do just that we should prop the rear of the bike up, remove the rear brake calliper, the rear wheel, the chain, the shock absorber links, both riders foot pegs, the brake master cylinder, remove the swing arm spindle and then remove the complete swingarm. Lubricating then becomes a messy job of pulling out the spacers, cleaning old grease from the bearings and poke new in with your fingers... Nice!

Grease nipples fitted, from now on the swing arm bearings can be greased without stripping the whole back end of the bike
Of course the other option would have been to fit grease nipples in the factory... I fitted two and they cost me all of 57 cents. Greasing is now a matter of attaching a grease gun and give it a couple of squirts until the grease comes out. It literally takes 2 minutes to do now. Had Yamaha been customer friendly enough to fit the grease nipples then non of this would have happened. Grease nipples cost all of 57 cents, the Yamaha rebuild kit a whopping 164 Euro...

As you can see in the photos I've fitted the grease nipples between the bearings, which is an easy process. On an XT-R the bearing recesses 4 mm in the swingarm, while the bush recess is 8 mm. In between is a nice spot for an M6 (or 1/4") 45° grease nipple. The one on the chain side faces inwards for easier access from the right hand side. This modification can be done with the bearings still in place too, but you'll have to remove the swingarm to do it. Just protect the needle bearing from debris while drilling by sliding the spacer half into it and clean out any debris from the other side. Tap M6 (or 1/4" depending on the nipple), fit the grease nipple with a dab of Loctite and... done! Well, almost! Once assembled again, hookup the grease gun and squirt some grease into it. Depending on use once every 5.000 to 10.000 km should be enough. Don't overdo it by pumping a mass of grease into it as this will push the end-seals out. A small mod I did to those seals is zip-ties around the swingarm to keep them in place. 

The squeaking in Mike's XT660R is gone and with just a small regular dose of grease the swingarm bearings should now last forever.

Having seen the state of the swingarm bearings, I wondered about the steering head ones... I'm glad I did! Sure enough they were pretty dry too. Fitting a grease nipple here isn't practical as there is no seal above the bearing. Re-greasing them is not a big job however. Contrary to popular believe there is no need to disassemble the front end. 

Freshly repainted with a brush, as it
isn't visible behind the plastic
panels anyway
All we did was prop the bike up slightly at the front, making sure it is stable. Remove the handlebars and suspend them from the ceiling or so to prevent removing the cables and such. Then slacken off the central steering head nut, loosen the leg clamping bolts of the top yoke (or triple clamp) and remove it. Undo the two top nuts and locking washer, which gives acces to the top bearing. Remove it completely and make sure everything inside is clean. Inspect the bearing and then jack the bike up slowly, this will give access to the bottom bearing of the steering head. Again clean it and inspect it, re-grease if the bearing isn't worn. Don't skimp on the quality of the grease, bearings are much more expensive than a grease cartridge. 

Slowly drop the bike down again. It's best to do this with the aid of an assistant guiding the forks back in place. Then grease the top bearing and assemble it.
While we were at it we also did, another, de-rusting session. Not sure what kind of paint they used but anything available in the local hardware store is going to better than what's on there! Especially the bottom of the fuel tank was getting slightly worrying. As this is an area which is usually dry due to the heat from the engine rising up, it must have been very poor quality paint or painting, or both!