I just completed a quick inspection and lube of the front suspension in response to hearing a slight squeak at times. Reports abound of finding one or both of the upper suspension arm bearings corroded away so the old girl has been parked for a few weeks so as not to cause any further damage while I got around to tackling the project.
It turned out to be a bit easier than expected. Not being used to working on a fully-faired motorcycle, removal of all the crap necessary just to get to the bits I was interested in was the main obstacle.
Here are some notes and photos:
Removed the four allen-head cap screws holding the front of the fender and the six bolts for the rear. Removing all the allen screws holding the brackets, etc., turned out to be unnecessary.
After removing the front wheel, bellypan, lower fairing panels, rubber flap over the A-arm and rubber cover over the right side bearing (right side of the bike, left side of these photos,) plus detaching the steering tube and tying it up, I could get at the bearing bolts. A long extension allowed a straight-shot at the nuts.
The A-arm is set up so the left side can be adjusted left-to-right (the camber adjuster) and the right slides on a bearing sleeve with no sideways thrust control.
The right side bearing bolt pulls out of the frame to release that end of the A-arm. The left bearing is a spherical bushing (basically a captured ball with a bolt through it) so once you remove the alignment sleeves, the A-arm can pivot out enough to slide it off the left side pin (which remains in place). It was necessary to pull the brake hose and ABS sensor wires out of their clips underneath the arm.
The right side needle bearing showed some signs of wear and the grease was dry - but it was tight and spun freely and the seals looked ok so I simply cleaned and re-greased it.
Yamaha recommends a moly grease although that did not look like what was in there. I happened to have some on the shelf.
The spherical bushing had a trace of red, indicating that perhaps the bearing seals are not as water-tight as they should be and from the wear is almost certainly the source of the "squeak!" - Just as expected. Strangely, this side is not also protected by a rubber boot.
Despite its appearance, the bearing appeared tight and smooth so I rotated it around to clean it in-situ and repack the groove with grease
When retorquing the left pivot bolt nut, I had to hold it from the outside with an allen wrench to prevent the bolt from turning, thereby messing up the camber adjustment.
I'm a great believer in "if it ain't broke, don't mess with it". As the upper and lower ball joints supporting the knuckle arm were both moving freely with no play when gently levered and the boots were in good condition, I left those alone.
With the lower suspension arm suitably supported, the shock could be unbolted. The lower eye is another spherical bushing and was in perfect condition. I added a little grease and put it back together. As there was no discernable play in the upper eye, I left that alone too.
I removed both the lower suspension arm bearing pivots by undoing the castellated nuts and pulling the pivot bolts out. The bearings on both sides appeared to be sealed units in great shape with no signs of water intrusion, free play or roughness, so they went back together with no action taken.
Reassembly was a reverse of the dis-assembly process. I pulled some of the attachment "tits" off the A-arm rubber cover while removing it, but it proved easy enough to hold in place with cable ties through the existing holes.
All that remained was to check everything was back together, brake hose clipped back in place, bolts torqued, etc., then replace all the bodywork. There are so many screws and bolts holding this all on but after doing it a few times now, it doesn't take long.
Initial testing seems to show that the "squeak!" has gone.