Rear shock movement at the bottom - MOT fail

[papercutout]

It was what my MOT tester was most concerned about with my bike. If you put the bike on the centre stand and lifted the rear wheel up at down, the movement is at the bolt at the bottom of the rear shock, where it goes through the pivot arm.


It's got 1-2mm of movement, and a little off-putting. Are they all like this?


I've taken the bolt out and looked, but it's a metal sleeve through the pivot arm, so I cannot see any way it could be rectified (I did try putting some sealant in there to see if it'd fill the space, but it hasn't worked). It was tight when I came to it, so not caused by slop. It's only a 25K bike, so it shouldn't be 'worn out' already.


Any suggestions?
Thanks

[stevierst]

Erm, I'm pretty sure they all have a little 'movement' there, otherwise it would be an engineering fit, and that would be rather costly to produce.
Your MOT bloke should know that.

[Fazerider]

If that movement is at the linkage it sounds like the bearings are shot.
The sleeves run in needle rollers... dismantle a bit further and you'll doubtless find some have a bunch of rusty rods instead of nice shiny rollers.
About 2mm vertical movement at the rear wheel is normal though, the tiny amount of slop at each pivot adds up and is magnified by the leverage.

[papercutout]

I've just pulled it apart again, and there's slop in the rubber bush that is around the metal sleeve. It's not disintegrating though, as you'd see in an old bush, no cracks etc.

I'd expect a normal bush to 'flex' not clonk up and down...


Fazerider - the movement is only in the one place, the rest of the pivot arm is fine. Literally only where the bolt goes through the shock and arm.

[Fazerider]

The rubber "bush" is just an oil seal to try to keep the weather out of the bearings... you need to lever those out then drift the remains of the bearing out and replace them.

[papercutout]

Where would I get one of those bearings? Yamaha only?
Thanks

[Fazerider]

I bought Yamaha ones last time I had to replace them, though you can probably find them at a bearing factors.
It's a pain, but well worth taking the whole relay arm/dogbones off and regreasing them, especially if you ride in all weathers. I try to do it every two years, but find that's not really frequently enough for my riding habits... winter road salt gets in there too easily as they're so exposed to spray.