Final Drive - metal 'dust' in oil

[azellner]

So I'm changing my final drive oil for the first time, and there's a glob of metal 'dust' on the drain plug. Skimming through the post on final drive failures, I see reference to 'shavings' and 'metal slivers', but that's not how I would describe what I'm seeing. Its a oily, silver glob, maybe the size of a large pea. So is this normal, or am I counting down to a rebuild?

More info: Its a 2002 R1150R with 37k miles. I've owned it for less than 2k of those miles, so its possible that the oil has never been changed, but I don't know.

Thanks!

[Xdot]

I can't comment directly on the final drive but I can say that almost any rotating mechanical system will create the metal dust you describe. The very reason for incorporating the magnetic drain plug. From that standpoint this sounds normal. Can't imagine a final drive being much different.

John

[iowabeakster]

a dark glob of goo is normal... nothing to worry about.

shiny metal shavings is bad... those are pieces of the bearings or bearing races

[CycleRob]

A glob the size of a large pea is normal, considering the near pencil size of the magnetic cylinder it has grown on. What is real important is the size of those particles. Pinch the mass between your thumb and index finger, then rub the digits together. If all you feel is a paste like moosh, you're OK. That silver paste occurs as normal wear when the spiral bevel gear teeth "slide" over each other as they mesh when they turn. It should only be there on the first few oil changes when the gears are breaking in.

If you feel a gritty/grainy particle infestation, there's a serious and looming disaster in your future. That is likely bearing inner/outer race and ball wear material.

When my 2002 R1150R's FD bearings got loose enough to affect the handling, showing a visual rear wheel clunk-wobble by hand force, there was no unusual metal broccoli bush on the drain plug magnet or particles in the drainpan. Go figure.

.

[page62]

Mine was exactly the same when I changed the fluid at about 5K miles. I didn't worry about it...and according to what I'm reading here you shouldn't either!