Flakes in FD

[Canuck]

So I saw a few flakes of metal on my magnetic drain plug during the last oil change (2000 miles ago). As i have the week off I thought I'd use the time to investigate further . Today I drained the oil and there must have been about 10-20 small flakes... probably about the size of the whistle note in this smilie

What do I know...

1. That I'll be changing the paralever bearings as they are past their best...just need to get a better heat gun as mine isn't melting the loctite.

2. Just pulled out the FD seal and the bearing looks perfect... to my untrained eye.

3. Rear wheel has movement at 9 and 3 even with the rear brake on... hence the paralever bearing change.

What I don't know...

Where else could these flakes be coming from if the FD looks fine?

I won't get the paralever bearings out till tomorrow afternoon (when I borrow a heat gun) so I'll have a good idea then though I am planning to replace the lot.

Should I replace the FD bearing anyway? or are the flakes possibly from the paralever bearings if they are completely shot?

Any advice would be greatly appreciated.

 

[Sempione]

Does the bearing feel notchy when you turn the crownwheel by hand?

I had flakes in the FD oil when my crownwheel output bearing races were starting to desintegrate at about 70k miles. It was also noticeable as a vibration/rumbling through the foot pegs while riding.
I changed the bearing with the help of a thread on here and so far it is still ok after 15k miles.

The flakes will not be from the paralever bearings as these are not running in the oil. Candidates for the flakes are the crownwheel or pinion bearings.

 

[Canuck]

I have compared it to my 1100 GS... both bikes have 32000 miles on them. My GSA doesn't seem to turn as smoothly as the 1100... and although it is not crunching it does seem to have not 'not so smooth' areas.

There a slight vibrations through the footpegs on the GSA though I'm not sure if it is just the tyres. I'll look up these other bearings and see how I access them... what thread are you referring to? Thanks for the tip!

 

[littleredrooster]

Unfortunately my best guess is that the bearing cage is starting to break up; that's possibly/probably the source of the metallic flakes - it's an early sign of bearing failure. The cage eventually lets loose and the balls are free to run to the 'unloaded' side of the bearing.

This is called 'crowding' and bearing failure often happens soon afterwards.

 

[Sempione]

I first thought that the vibration was from the Heidenau K60 tyres but it quickly got worse. Within 200 miles I decided to stop riding until it's fixed.

Have you removed the caliper before turning the wheel?

Once you have the FD off the bike to change the paralever bearings the damage to the crownwheel output bearing should the pretty obvious when you turn it.

This thread and the contained link might help if you need to change the crownwheel output bearing.
http://www.ukgser.com/forums/showthread.php?t=119346&highlight=rear+wheel+bearing

 

[Canuck]

Thanks for the tips. I've done some more reading and once I get the pieces apart it should be obvious what has gone wrong. I'll post back up here when I figure it out... and I'll get some photos if I can find the camera.

So much for the quick and easy paralever bearing replacement! Looks like I may need some new tools as well! In particular I'm missing a 7mm hex bit... I have every other size but a 7! Would also like to get a bearing puller... but with funds a bit low may have to wait for another time.

 

[MattW]

Thanks for the tips. I've done some more reading and once I get the pieces apart it should be obvious what has gone wrong. I'll post back up here when I figure it out... and I'll get some photos if I can find the camera.

So much for the quick and easy paralever bearing replacement! Looks like I may need some new tools as well! In particular I'm missing a 7mm hex bit... I have every other size but a 7! Would also like to get a bearing puller... but with funds a bit low may have to wait for another time.

You can drift the bearings out from inside the swingarm using a socket and extension bar (assemble it by posting the extension through the other bearing).

 

[Canuck]

Okay I have everything pulled apart... the first heat gun didn't work so I had to go back to town to buy another. For the record... if you get those two bolts holding the paralever bearings nice and hot... they come undone really easy... so I don't want to hear of people stripping their swingarm because of the loctite!

Anyhow there are no flakes or anything that looks remotely damaged inside the FD. However the bearing is a bit rough... so I'm going to swap it out. Perhpa I'll see some wear on it when I remove it.

The Paralever bearings were worn but still in place and intact... there was wear on the right side threaded bolt so I'm guessing the bearing wasn't doing its job properly. That will be replaced as well.

I'll replace the bearings then put it all back together and see how it feels. I can't find my camera so no pictures I'm afraid... the in-laws took it by mistake a few weeks ago and were supposed to bring it back but that didn't happen.


Hopefully I don't get any more flecks in the FD oil next change otherwise I'll really be scratching my head.

 

[Welshman]

In an aid to prevent paranoia...

I had a failed FD bearing with the flecks and drained the oil changed the bearing etc... later on probably drained off oil and left the residue in the bottom of the drain tray...

Later (a month or two) used same drain tray for an engine oil change (no I had not put it through the dishwasher)....

On getting rid of the engine oil, (I assume the final drive flecks had settled into the residue at the tray bottom).. Oh kark.... just see the metal flecks, spend the next month or so expecting the motor to detonate, nothing 2 oil changes nothing, ok assume it was the FD kark....