Final Drive

[Our Gee]

On my previous RT a Final Drive oil changed involved removing the Rear Wheel speed sensor and using the aperture as a fill point. On my 2011 bike there is a M12 Screwed Plug (Part No. 07 11 9 904 550) in the hub backplate, positioned at about 9 o,clock when viewed from the off-side. Is this plug intended as an oil fill point ?.
Many Thanks.

 

[Dennis the Menace]

There has always been a screwed plug there, (used to be oil drain plug on older 1200) so yes you can use as an oil fill point (180cc of oil)

 

[Our Gee]

Thank you for the reply Dennis. My previous bike did not have a plug in the position I described. That's why I used the Speed Sensor location for adding oil.
Draining oil was carried out by lowering the Final Drive through 90 degrees and drained by removing the screwed plug located in the actual "Hub" casting.
I didn't want to remove the plug I described above until I knew exactly what it was for.

 

[Dennis the Menace]

Why not just use the screwed plug hole in the Hub casting, the amount of oil used wont overflow the plug level

 

[mikeyboy]

There has always been a screwed plug there, (used to be oil drain plug on older 1200) so yes you can use as an oil fill point (180cc of oil)

i would refill with 200ml of oil.
in my experience 180 is not enough and causes premature pinion nose bearing wear

 

[Cortina]

i would refill with 200ml of oil.
in my experience 180 is not enough and causes premature pinion nose bearing wear

Interesting (how do you know this exactly ?) since BMW changed (revised) the quantity down to 180cc from what was originally used (and from what is on my service CD) !! ??

 

[Miggs]

Interesting (how do you know this exactly ?) since BMW changed (revised) the quantity down to 180cc from what was originally used (and from what is on my service CD) !! ??

As I understand it...200ml was an error in the manual. Overfilling by that 20ml was the main reason for blown seals.

 

[Cortina]

As I understand it...200ml was an error in the manual. Overfilling by that 20ml was the main reason for blown seals.

so the 180cc figure is correct ! ? .... hence my question above.

 

[seahorse]

180ml

 

[Mr Bean]

180ml

My suspicion is that the 200mls was the correct figure at the time of design but subsequent seal failures meant that it was easier to recommend a lower volume to reduce the number of warranty claims on leaking seals.

Changing the seal is a very quick and inexpensive job - compared to bearing failures in the FD

 

[seahorse]

220 was the original spec. I used to use 200 but in the hot weather recently I had a minor leak. Decided to change the seal anyway as its a piece of piss to do. When I levered the seal lip away from the axle tube there was a little psssst.... so there was definitely a pressure build up in there. Will use 180 in future.

 

[mikeyboy]

Interesting (how do you know this exactly ?) since BMW changed (revised) the quantity down to 180cc from what was originally used (and from what is on my service CD) !! ??

i strip and rebuild final drives as a core part of my bmw service and repair business.
every final drive unit i overhaul has worn out pinion nose bearings.
the original capacity was quoted as 220ml,
this was reduced to 180ml due to seal "misting"
i personally think it is better to have a bit of misting or at worst replace a £10 seal ,than have premature bearing failure.
that said i have never had any negative feedback from customers when the unit has been filled with 200ml.zero reports of seal failure.
mike

 

[Dennis the Menace]

So there you go, 220, 200 or 180 the choice is yours

 

[Our Gee]

220 was the original spec. I used to use 200 but in the hot weather recently I had a minor leak. Decided to change the seal anyway as its a piece of piss to do. When I levered the seal lip away from the axle tube there was a little psssst.... so there was definitely a pressure build up in there. Will use 180 in future.

Interesting to hear of the Pssssst you heard Seahorse. I take it that your Final Drive is the pre breather type. My other RT, the one without the Screwed Plug I mentioned in my original post did not have the breather whereas my 2011 build bike does. As the later bikes have the breather type final drive I would have thought it would be impossible for any pressure "build-up" to occur and in this case adding a few more drops of oil over the recommended 180cc should not be a problem and should help avoiding the bearing failure as described by mikeyboy. Well that's the way I see it !!.

 

[seahorse]

Mine is a 2008 so correct, no breather. Never understoosd that as every other FD I have seen has a breather

 

[dicktheleg]

Is this the "filler plug" you mean, and can it be used to refill the FD.

 

[Our Gee]

Nice clear picture there" dicktheleg". Yup, that's the one. Having another "think" on the subject could it be that the original 220 ml of oil was too much without any vent for thermal expansion which did cause some seals to fail, as an interim solution BMW reduced the quantity to 180ml prior to the introduction of the modified unit with the "breather". It would be nice to know if the oil quantity was then increased to the original 220 ml. Anyone in the know out there ?.

 

[dicktheleg]

Has anyone removed that plug and refilled through it?

 

[Cortina]

Has anyone removed that plug and refilled through it?

Yes , I have ... no problem. Bike now with 72,000 ... no issues...... 180cc used , and I guess about 180cc came out (visual check , not measured exactly)