My wife and I are currently in Buenos Aires and this morning I changed the gear oil (1998 bmw 1100gs with 90000 km, last changed the oil about 12000 km ago). I noticed that the magnetic drain plug was covered with grey paste. In addition, there were very fine flecks of metal on the plug (also in the oil).

Is this a major issue or can we head down to Ushuaia?

Thanks,

Brian

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Brian

www.2uprtw.com

I suppose it depends how many crunchy gear changes you have done in the 12000 km. If everything seems to be ok with the bike, I wouldn't worry to much but would do the next oil change a little prematurely just to see if it's an on-going issue.

I have no BMW specific knowledge but have found metal in the oil on my bikes on much shorter service intervals than 12000 km and haven't worried about it.

I have a 1999 R1100GS and there I always some 'gray paste' when changing the gearbox and final drive oil. I have never had metal fleks ...yet . I think the advice akready given is sound - do the next oil change a bit early and keep and eye on it but don't let it bother you too much , after all what can you do about it now - carry a spare gearbox and final drive on your trip ? :confused1:
Are you using mineral or synthetic gear oil ? I use fully synthetic in mine and have done for years .

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If the oil is filled with very fine particles such that it resembles thin metallic silver paint, it's the aluminium selector forks that are wearing. As aluminium isn't magnetic, the particles will not stick to the magnet in the drain plug. Eventually you'll find the bike will start jumping out of gear as you try and shift up.

If that's 'all' that's producing the flecks you'll be OK until shifting becomes a problem. If it's OK now it's should be fine for a good while more, but as suggested, keep an eye on the oil. My 1100 produced shiney oil for a few thousand miles before it started jumping out of gear.

Some grey sludge on the magnet is normal. Big flecks of ferrous metal are not a good sign and indicate that either a bearing or gear teeth are damaged, or you have been crashing through the gears a lot..

1100 gearboxes have undergone several modifications to prevent premature wear of the bearings and moved from open to sealed bearings along the way. Have a good search in the UKGSER site as there are loads of threads on this giving lots of good info'.

Good luck

As said before.

On '98 you have the M97 gearbox, which has a lot less problems than the M94 gearboxes (1994-1996 models).

Mine is '98 1100 also and I get normal amount of metal-grain collected on the magnet at every service when I inspect it.

I change gearbox and finaldrive oil at every 10Kkm, the same time as engine oil, so it's all the oils every service for me. Since it's so easy yet cheap to change the transmission oils. If you ride your bike on very bad roads think how much work they have to do.

If the metal particles aren't more than few millimeters long "slices" and no more than one millimeters thick sticking out of magnet then it's a normal wear for gearbox and nothing to worry about. And very fine metallic dust mixed with oil, "gray paste" as you call it, is absolutely nothing to worry about. Typical bigger metal particles on my gearbox magnet can be relatively long (few millimetres) but very thin. My bike is now over 80,000km, and it's been the same from the beginning.

On final drive magnet I mostly get only metallic dust - very fine particles "gausially" collected around the magnet. Reading at UKGSer or ADVrider - if big noticable metal bits stick to the FD magnet, then it's a warning sign for the crownwheel bearing is about to end it's work contract .

Ride safe, Margus

Thanks to all for taking the time to respond. On the advice of others and based on the fact that I found a small piece of metal on the magnet (big enough to roll around on my fingers) we decided to take the gearbox apart here at Dakar Motos. What we found was that 5 of the 6 bearings were worn, some more than others. One in particular was obviously worn on the outside (the rear bearing of the input shaft gear). Other than the worn bearings everything seemed to be OK and the gearbox is now back together. Hopefully this change of bearings will resolve the issue!

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Brian

www.2uprtw.com

Glad you are sorted now.
For future reference, grey paste is fine, flakes are not. Always a sign of impending bearing failure. Ie if you can feel any individual particle it is a problem. ( although not usually of the sudden catastrophic type)