Rear Drive Bearing Failure

[redcat255]

I believe the bearing in my final drive (2007 R1200RT) is failing.  While the wheel spins freely, after my last ride, I noticed grease coming from the final drive, and the final drive was quite warm.  I have grease on the rear wheel and brake rotor (actually the ABS warning was what tipped me off).  I had the drive serviced (fluid changed) about 7K miles ago.  The bike is now parked until I figure out what to do next. 
The options as I see it:
·        - Have the bike towed to the BMW dealership for (probably) an expensive repair (plus $150+ for the tow).
·        - Remove the final drive from the bike and bring it to the BMW dealership for refurbishment.
·        - Remove the final drive and send it elsewhere to be refurbished (I have two recommendations, and both of these are dealerships, also).
·        - Buy a completely new drive ($2K)
·        - Buy a used drive of unknown history off of eBay for $800 and install myself.
Anyone have any similar history or suggestions?  On a related note, has the original P/N been superseded by a redesign of this assembly?
Thanks in advance.

[David.]

Have the final drive unit bearings been check for play. Where is the oil coming from, could it be an FD unit seal, "O" ring on the drain plug or ABS sensor. The FD unit is likely to get warm during normal use. I believe that the ABS sensor needs to be removed to fill the FD unit with oil. Was there any evidence of the oil being contaminated when it was changed.

[redcat255]

David, thank you for the reply and your thoughts.  The fluid does not at all appear to be the gear oil as the viscosity seems too high for gear oil, even cold gear oil and this was hot.  I had no reports of contamination when the gear oil was changed 7K and 12K miles ago.  I have never had any shop (when changing the rear tire or the gear oil) mention any issue with bearing play, although I am not sure it was ever specifically checked.

[David.]

In which case, if it's grease, it could be from the splined UJ driveshaft to FD unit joint which has to be split to drop the FD unit to drain the oil.

What kind of condition is the rubber boot between the FD unit & swingarm in, could this be where the grease has come from.

Or, could it be grease from the wheel bolts.

[redcat255]

Boot is good and clean.  Ran my hand under the swing arm and drive, and did not find grease until almost completely under the rear hub.
I thought about grease from the drive u-joint area but (based on videos I’ve seen on rear drive service) this seems to be more than what I’d expect from that area or wheel bolts.  The gear oil is for the gears, but are the bearings lubed by the same gear oil?  I was thinking they were grease packed.
And I need to clarify, while the wheel spins, there is something “dragging”.
I suppose I need to go in and drop the drive and get a better look around.  That will have to wait until next week.

[David.]

Before spinning the rear wheel, remove the rear brake caliper and suspend it out of the way, that will eliminate any interference when checking the FD unit.

[David.]

The gear oil is for the gears, but are the bearings lubed by the same gear oil? I was thinking they were grease packed.

This thread may be helpful, viewtopic.php?p=37648#p37648

[redcat255]

Thanks again for advice and link.  I won't be able to pull the caliper and FD until next week, but will let you know.


I found the thread you referenced extremely interesting, particularly the comments that . . .


"On RT final drives on the hex heads (05-09) the FD "big bearing" is placed in the housing on the flange side of the bevel gears and is not running in the 75W90 gear oil.""Starting in 2010 up to present (2017) on the RT, the "big bearing" is on the inside of the housing WITH the bevel gears and running in the 75W90 gear oil."


. . . which makes me want to ask . . .

1. Are the 2010 and up FD's interchangeable with the earlier (2007) FD's?  The reference thread indicates maybe 2017 or beyond will work.


2. Why wouldn't I just be looking to find a used 2010 and up FD on eBay to swap?  Swapping looks easy if they are compatible (and would be more durable with the bearing running in gear oil) and would likely be less expensive than to rebuild the non-oil-running design I have.

[David.]

If there is no evidence of mechanical damage, the FD unit oil is clean without any metallic particles in it, plus no play in the bearings themselves, you might get away with re-greasing the big bearing & replacing the seal.

[David.]

Are the 2010 and up FD's interchangeable with the earlier (2007) FD's?

I panicked when I had my FD large bearing failure a week before an Alaska ride back in 2014 on my 08RT...I bought 2 complete FD units to insure I had one good one to swap out for my ride. The one that I installed that worked perfectly was from a 2010 RT that I removed when I got home and did the rebuild of the original 2008 FD.

[redcat255]

Thanks again.  Will update next week.  Enjoy your weekend.

[redcat255]

Finally able to get the bike into my workshop.  Disassembly is going well.  A couple observation and a couple of questions.  I am on a path to get the current drive rebuilt once I remove and send off.  The drive has 29,543 miles, and was last serviced at my local BMW motorcycle dealer a little less than 2.5 years ago and 8,230 miles ago
With the rear brake caliper removed, the rear wheel is definitely dragging.  It turns, but not freely.
The ABS sensor is loaded with fresh chips.  Maybe not too surprising, does that mean anything in particular?
When I drained the final drive gear oil, I noticed the magnetic drain plug was full of magnetic slurry or a mix of oil and magnetic material.  I assume that is not good.
Driveshaft-to-drive spline looks great.  Well lubricated.
Any immediate comments, thoughts or guidance on moving forward?
I’ll be pulling the lower drive bolt later today or tomorrow.  I think this is installed typically with red Locktite.  YouTube video (go to 2:20 mark of https://www.youtube.com/watch?v=eO_RbcNTaic&ab_channel=AdventureDream) shows heat applied (104 deg. C) to release Locktite, and then hook and drift to remove right and left hand side sleeves, respectively. I have a small propane torch, but am concerned propane is too hot. Anyone have experience with disassemble of nut/bolt and removal of sleeve? 
This is a hassle, and will be expensive, but is kind of fun, too.

[Beagle]

You could try a heat gun

[redcat255]

Agree!  I just bought one from my local hardware store.  Variable settings from 125 to 750 deg. F in 10 degree increments.

[redcat255]

[size=2px]Drive is headed out for rebuild.  Three week turn time estimated.[/size]