‘04 K1200GT Uh, oh... metal shavings in final drive oil!

[corey61]

A question for the Collective:

After a recent long tour, my 2004 K1200GT was ready for an oil change. Though it had only been 6k miles since the final drive gear oil had been changed, I went ahead and changed that, too. I found some substantial metal slivers or shavings collected at the drain plug magnet, the likes of which I have never seen before on this bike, in 17 years of ownership:

1. Drain plug, immediately after removal
2. Drain plug after dabbing away some of the oil (shavings easier to see, stuck to the magnet)
3. Oil dabbed onto a shop towel, with some shavings
4. Shavings picked out and dried

This is new and different and probably not good. Something is going to pieces in my FD, and I’m wondering if anyone here has seen something similar. Anyone care to weigh in with an opinion on what’s going on?

There is some additional backstory regarding recent developments with this FD - which is why I changed the gear oil after only 6k miles - but nothing that gives me an Aha!-type guess as to what’s failing.

Anyone…?
Thanks!

 

[pauls1150]

SWAG: Either a bearing or a seal is coming apart. Or both, since if a seal goes, then the bearing it's protecting loses its lubrication.

 

[corey61]

Yes, thanks - that's my guess, too. It's a long story, but I do know that the pinion-gear bearing's plastic cage (holding the bearing balls) is cracked, split in two. My local independent mechanic found that back in early June and re-assembled the pinion gear ass'y with that cracked cage. So the pinion-gear bearing is suspect #1 for the root cause.

 

[riderr1150gsadv]

How many miles on that FD?? If it is near 100K then all you need to do is replace the main bearing and the big seal and that is really it. If it lasted that long the general consensus was that the FD was shimmed properly from the factory. You do have to check all the other parts and pinion seal etc since it is apart at that point , but there is no reason to panic. YMMV JMHO...

 

[jandhumphreyme]

Yes, thanks - that's my guess, too. It's a long story, but I do know that the pinion-gear bearing's plastic cage (holding the bearing balls) is cracked, split in two. My local independent mechanic found that back in early June and re-assembled the pinion gear ass'y with that cracked cage. So the pinion-gear bearing is suspect #1 for the root cause.

If your running the pinion bearing with a cracked cage, winner winner. Stupid question but why if you had the drive housing apart would you put a defective bearing back in? I would think it needs a rebuild before you wallow out the pinion bearing seat and need a new housing. Good luck, please post photos if you do the work yourself or report back the final diagnosis and repair.

 

[corey61]

How many miles on that FD?? If it is near 100K then all you need to do is replace the main bearing and the big seal and that is really it. If it lasted that long the general consensus was that the FD was shimmed properly from the factory. You do have to check all the other parts and pinion seal etc since it is apart at that point , but there is no reason to panic. YMMV JMHO...

The bike has only 46k. I bought it five years ago with 11.6k miles on the clock. Have ridden it over 11k since March of this year - several long tours.

 

[corey61]

If your running the pinion bearing with a cracked cage, winner winner. Stupid question but why if you had the drive housing apart would you put a defective bearing back in? I would think it needs a rebuild before you wallow out the pinion bearing seat and need a new housing. Good luck, please post photos if you do the work yourself or report back the final diagnosis and repair.

Not a stupid question at all - it is, of course, what we'd all do in a perfect world!

The reason my mechanic put the cracked cage back in place was that he couldn't find a replacement anywhere in California; it would've had to come from Germany. (He was into the FD to replace a leaky pinion gear seal.) AND, I was scheduled to leave on a 5-week tour only four days after he did that work - with itinerary and reservations locked in.

BTW, he had a heckuva time getting the pinion gear assy apart so he could swap out the seal. Had to disassemble it - something he said he'd never had to do before, in many pinion gear seal replacements over the years. I was sitting in his shop watching him work and he showed the cracked part to me when he found it. After calling around and not locating a replacement, we put our heads together and agreed that given the configuration of the bearing, the cage wasn't subject to any significant loads and would be well seated, even though it was in two pieces rather than one.

So... that's what he did, and off I went on that long trip. 5800 miles and 38 days later, I was back home and the bike was due for an oil change. It was for this reason (the cracked bearing cage) that I decided to change the FD gear oil as well. And discovered this disturbing situation...

MEANWHILE...

Since I posted, a contributor on another forum has stepped up and offered me a loaner FD; in fact, it shipped today and I'll have it on Tuesday. That'll allow me to keep riding the bike while I take the existing FD unit back to my mechanic. I won't do the work on it myself because I lack the special BMW fixture that holds the unit while you wrench it open. Another possible path is for that forum contributor - who says he has rebuilt over 150 of these FDs - to do the rebuild or a swap for me, and I install it sometime down the road.

In any event, I'll report back when the root cause is found!

 

[jandhumphreyme]

Great news that you found a replacement and a path forward to getting things sorted. My question was more rhetorical but unfortunately the internet is bad at capturing voice inflection and facial cues. I do understand life getting in the way all too well. Looking forward to your next report, good luck.

 

[riderr1150gsadv]

The bike has only 46k. I bought it five years ago with 11.6k miles on the clock. Have ridden it over 11k since March of this year - several long tours.

That's a tough one but my suspicion is that it (bearing) wasn't shimmed right and this would need checking for sure when it is being rebuild. It really is unfortunate that with such low miles this issue is popping up...

 

[AntonLargiader]

I see a LOT of failed FDs but that is not the typical debris. Are those shards steel or aluminum?

Does your mechanic do a lot of BMW final drive work?

 

[pauls1150]

Pics 1 and 2 say steel, but pic 4 says "mixed"....