Noise from final drive

[spacesenator]

Hi there,

I'm having a problem with my '98 R1100R.

The bike has about 12,000mls on it, I've ridden it mostly on long trips with a lot of luggage. I don't know what the previous owner did with it except for dropping it on both sides within his 4,800mls. Also, it looks like the front of the engine case has been disassembled before as there are rests of silicone sticking out (didn't see that until after I bought the bike in Dec).

Here my problem:
At a speed of 60mph and up, I get this weird noise very similar to a car driven fast in reverse. It gets worse at lean angle in turns.
The problem occurs whithin the first 20mls and then usually gets a little better for a while. The noise is completely independent from the RPM of the engine, if clutch engaged or not, or which gear I'm in.

I first thought it came from the gearbox, but I'm pretty sure that it's actually from the end of the drive shaft.

Any idea what I'm looking at? Is that a common problem?

[boxermania]

spacesenator

The first thing that comes to mind is a bad diferential bearing......put the bike on the center stand, with the gearset in neutral and rotate, by hand, the rear tire in the direction of rotation. If the rotation is not smooth and kind of grindy that is a sign of a bad bearing.

The reason it gets better is because the oil warms up and so does the bearing, tightening the clearances.

Good luck and let us know how you make out.......

[spacesenator]

Hi Boxermania, thanks for your reply.

I rotated the wheel on the center stand in neutral, but other than the rear brake pads I didn't hear or feel any rough running.
I'll probably pull the caliper to be 100% sure and let you know.

It's kind of weird: 12,000mls is kind of young for the bike, and even lots of luggage should not cause excessive wear...

[bang]

Might also be the rear wheel bearing. I had to have mine replaced on my 2000 1100R while on a cross country trip. Logics of low milage or usage have nothing to do with it. Since having the problem I have learned that this is not an uncommon mechanical failure - even on bikes with low miles and light use.

Find the problem before it parks you in the middle of nowhere!

[reidmct]

A shot in the dark... but, check your tire.

[Paul White]

I drain my final drive oil into a white plastic tub. I also wipe the magnetic drain plug to see if any of the usual dark residue is hard. While I'm at 54K and no problems, this is probably the bike's biggest weakness from Internet posts and from the BMW Owners News magazine articles... The final drive oil change interval is 12K - I'm changing mine more frequently. I use synthetic but am very careful to use the bike's oil spec - Mobil 1 Synthetic 75W90 Gear Oil