Poll about Final Drive (Bevel Gear) Oil Spillage on the rim and tyre
- Thread starter Didi
- Start date
kate_brett
Active member
First noticed Aug 2023. Dealer cleaned and inspected. Told to observe. Informed them in Oct 2023 still occurring. Told that they needed “ special tool” to be made before could attempt service. Called by dealer in early Jan 2024 that “special tool” yet to arrive ( from Germany/Australia ? ). Still waiting. Fabulous customer service by BMW. NOT blaming dealer. They have been good. JMac74 - have you had your problem with leakage fixed yet ?
DaveO
Member
Where are you in Aus? I had mine done in Brisbane in August 23, they inspected it told me the seal had gone and booked me in for warranty, I did have to wait for the seal to arrive but no mention of a ”special tool”.
Before and after.
Attachments
These are sealed units, aren't they? This problem sounds eerily familiar to the old r1200c final drive seal leak issue, except the leak on the r1200c could end up in catastrophic failure of the final drive unit....
The issue was that, BMW refill specs were such that, when the air expanded in the sealed final drive unit, it had nowhere to go except the weakest point, which was the output seal to the tire itself. Over time, heated air would pneumatically press the output seal outwards until one day...BAM! total loss of all final drive fluid, and total loss of the final drive unit itself!
The solution that the Chromeheads forum came up with was to NOT fill the final drive to the capacity that BMW laid out in the service manual (remember those???
). Instead, we would fill to the BOTTOM of the screw threads, not until the lube drips out. I went onto https://www.chromeheads.org/ to see if I could find the posts talking about the final drive fixes, but they've since gone into the old archives (it's been a minute since I owned my first r1200c 
, and I'm going completely from memory here).
The gears splashed the gear lube onto themselves regardless of the lesser quantity of gear lube, and nobody in the community reporting any ill effects from the reduced fill amount.
I'm wondering if history is repeating itself here....
Mike
The issue was that, BMW refill specs were such that, when the air expanded in the sealed final drive unit, it had nowhere to go except the weakest point, which was the output seal to the tire itself. Over time, heated air would pneumatically press the output seal outwards until one day...BAM! total loss of all final drive fluid, and total loss of the final drive unit itself!
The solution that the Chromeheads forum came up with was to NOT fill the final drive to the capacity that BMW laid out in the service manual (remember those???
). Instead, we would fill to the BOTTOM of the screw threads, not until the lube drips out. I went onto https://www.chromeheads.org/ to see if I could find the posts talking about the final drive fixes, but they've since gone into the old archives (it's been a minute since I owned my first r1200c , and I'm going completely from memory here).The gears splashed the gear lube onto themselves regardless of the lesser quantity of gear lube, and nobody in the community reporting any ill effects from the reduced fill amount.
I'm wondering if history is repeating itself here....
Mike
kate_brett
Active member
Melbourne. They keep mentioning “ Special tool” yet to be made / procured.
Ulrich
Well-known member
That is 100% what I did on my 'ChromeHead' ... and never had an issue after.These are sealed units, aren't they? This problem sounds eerily familiar to the old r1200c final drive seal leak issue, except the leak on the r1200c could end up in catastrophic failure of the final drive unit....
The issue was that, BMW refill specs were such that, when the air expanded in the sealed final drive unit, it had nowhere to go except the weakest point, which was the output seal to the tire itself. Over time, heated air would pneumatically press the output seal outwards until one day...BAM! total loss of all final drive fluid, and total loss of the final drive unit itself!
The solution that the Chromeheads forum came up with was to NOT fill the final drive to the capacity that BMW laid out in the service manual (remember those???
The gears splashed the gear lube onto themselves regardless of the lesser quantity of gear lube, and nobody in the community reporting any ill effects from the reduced fill amount.
I'm wondering if history is repeating itself here....
Mike
Crna Gora
New member
I am having a small rusting spots on the reverse lever on my BMW R18. As far as oil leakage I do not have this problems for now.
Yeah,
I'm thinking when I do the final drive fluid change on Alcina next, I'm going to refer back to my old Chromehead days and underfill the final drive by a little bit.
BMW calls for 210ml. I don't see any harm in underfilling around 190ml. That gives the air that much more room to compress in during operation.
Mike
Ulrich
Well-known member
I agree .. on the 1200C it only took @-30 ml to make it stop seeping ... it didn't weep when I got her, but I changed all the fluids after a short while and then she did start seeping ... actually so bad there were stripes on the tire. Then I took a syringe and drew 30 ml out and after that, absolutely noting ... then I put 20 000 miles on hat rear end and had 0 problems
McGyver
New member
Had mine for a year and 1/2 before I could ride it Got the miles on it for 600 mile service . No problem noted. Took it in for annual and mentioned this had them check it out again. Yep leaking. Of course, my bike is out of warranty... Good dealership they are gonna try and get it done thru anyway as they have full service records and its low mileage due to not being ridden. We'll see
Good luck, BMW dealers can ask the Mothership for a Good Will repair for you and it sounds like your shop is on top of it. Please let us know how things play out.
My thoughts on the final drive fluid leak. The book says drain and refill at 210ml. Could the problem be that in the process of draining the old drive fluid, that enough residue fluid would remain on internal surfaces and crevices to make a 210ml refill an over fill? Question: How long do you let the old drive fluid drain....? Until you see the last few drips? Wait an hour or two? Overnight? I have no clue how critical the 210ml maximum fluid level is. Is factory recommended 210ml fill take into account remaining residue? After refilling with 210ml, could the residue make it 211ml, 215ml, 220ml?
Perhaps when the outside temp is 50F degrees vs. 95F degrees, the draining residue after a 20 minute draining would differ? Draining a cold vs. hot fluid make a difference? Maybe going back to post #48 is a good idea?
I know that changing a car engine oil there is a dipstick leeway between low level and full, but warnings just don't overfill. No dipstick in the final drive! My own experience when taking our car to the dealer for oil/filter changes there is typically a slight over the full mark dipstick level. They quickly drain until a few drips, plug it back and fill with book required 4 quarts or 5 with filter...just wonder how much old oil is still in the crankcase vs. draining overnight or crevices where old oil will accumulate regardless of drain time?
I guess the final question is "how critical is the final drive fluid level of 210ml"? Does 210ml take into account remaining internal old fluid residue and crevices? Maybe the 210ml is what a factory assembly line new final drive requires as opposed to replacement of old fluids?
Again, just thoughts......
EDIT: I guess the simplest way to not overfill your final drive if you have no indication of leakage....carefully drain the old fluid into a measuring container...if you drain 200ml., only refill 200ml. with fresh fluid. If you refill with 210ml., of course the drive will be overfilled...not good. Look at it in long term over several final drive fluid changes.....you could be overfilling as in this example...every time 10ml times the number of fluid changes. REALLY NOT GOOD!
Makes me wonder if dealer final drive/transmission changes take this into consideration ???
Perhaps when the outside temp is 50F degrees vs. 95F degrees, the draining residue after a 20 minute draining would differ? Draining a cold vs. hot fluid make a difference? Maybe going back to post #48 is a good idea?
I know that changing a car engine oil there is a dipstick leeway between low level and full, but warnings just don't overfill. No dipstick in the final drive! My own experience when taking our car to the dealer for oil/filter changes there is typically a slight over the full mark dipstick level. They quickly drain until a few drips, plug it back and fill with book required 4 quarts or 5 with filter...just wonder how much old oil is still in the crankcase vs. draining overnight or crevices where old oil will accumulate regardless of drain time?
I guess the final question is "how critical is the final drive fluid level of 210ml"? Does 210ml take into account remaining internal old fluid residue and crevices? Maybe the 210ml is what a factory assembly line new final drive requires as opposed to replacement of old fluids?
Again, just thoughts......
EDIT: I guess the simplest way to not overfill your final drive if you have no indication of leakage....carefully drain the old fluid into a measuring container...if you drain 200ml., only refill 200ml. with fresh fluid. If you refill with 210ml., of course the drive will be overfilled...not good. Look at it in long term over several final drive fluid changes.....you could be overfilling as in this example...every time 10ml times the number of fluid changes. REALLY NOT GOOD!
Makes me wonder if dealer final drive/transmission changes take this into consideration ???
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