Differential SEAL failure .....

[motorhead]

I finally picked up my diff rebuild parts last week and got into the bike Sunday.

Removing the differential assembly was easy enough, as was taking it apart.

** Whats odd was the seal had leaked halting my vacation trip 50 miles from home a few weeks ago, but thats it !! .....
Upon inspection after disassemble, there was NOTHING wrong with the crown bearing, retainer fully intact and smooth as silk rotation with no ball fretting ..... WTF ?

Found no nick in seals lip, no string wound up around it, no obvious reason why the seal allowed the oil out ?

Anyways, pulled off the old bearing and seal replacing them. At 42K+ figured it was a good preventative measure.

Talk about missing a bullet .... but still dead, life's odd that way :rolleyes:

[RocketRon]

Sure would make a tight right hander a little scary!
Good job!

[jzeiler]

Any oil seal is subject to failure at any time - just luck of the draw.

[Ted Shred]

I finally picked up my diff rebuild parts last week and got into the bike Sunday.

Removing the differential assembly was easy enough, as was taking it apart.

** Whats odd was the seal had leaked halting my vacation trip 50 miles from home a few weeks ago, but thats it !! .....
Upon inspection after disassemble, there was NOTHING wrong with the crown bearing, retainer fully intact and smooth as silk rotation with no ball fretting ..... WTF ?

Found no nick in seals lip, no string wound up around it, no obvious reason why the seal allowed the oil out ?

Anyways, pulled off the old bearing and seal replacing them. At 42K+ figured it was a good preventative measure.

Talk about missing a bullet .... but still dead, life's odd that way :rolleyes:

Thanks for the update. Glad it was a relatively easy fix.

[motorman587]

Looks like my rear tire a couple of days ago................Glad all is well.

[dshealey]

Glad it is going good for you.

Just a bit of information for future knowledge. The final drive is not a differential. It is only a right angle drive unit. A differential has "spider" gears driving two individual axles in a four wheel vehicle to allow the two tires to rotate at a "differential" speed when turning. Otherwise, one or both tires would have to slide around the turn. When only one wheel is involved, no differential drive is needed.

[hallzee]

Scott,

Glad it all came together!

[motorhead]

Glad it is going good for you.

Just a bit of information for future knowledge. The final drive is not a differential. It is only a right angle drive unit. A differential has "spider" gears driving two individual axles in a four wheel vehicle to allow the two tires to rotate at a "differential" speed when turning. Otherwise, one or both tires would have to slide around the turn. When only one wheel is involved, no differential drive is needed.

Error in my obvious ignorant naming of said part .... error noted :crazy:

[CharlieVT]

Even the BMW parts fische viewable on Max and A&S BMW's website refers to the "differential gear set" components of the final drive so it is easy to understand how the term "differential" gets used by folks here rather than the term "final drive" when referring to the assembled unit. I wonder if the "crown wheel" used in our final drive isn't the same part used in some differentials in other applications.

Glad it is going good for you.

Just a bit of information for future knowledge. The final drive is not a differential. It is only a right angle drive unit. A differential has "spider" gears driving two individual axles in a four wheel vehicle to allow the two tires to rotate at a "differential" speed when turning. Otherwise, one or both tires would have to slide around the turn. When only one wheel is involved, no differential drive is needed.

[rattler50]

If you hadn't stopped when you did, you might have had an FD failure and blamed it on the bearing.......Mine was just the opposite, the FD failed and the seal didn't leak. Good think your seal dumped enough for you to see............ :)

[Voyager]

Glad it is going good for you.

Just a bit of information for future knowledge. The final drive is not a differential. It is only a right angle drive unit. A differential has "spider" gears driving two individual axles in a four wheel vehicle to allow the two tires to rotate at a "differential" speed when turning. Otherwise, one or both tires would have to slide around the turn. When only one wheel is involved, no differential drive is needed.

Since the gear ratio isn't 1:1, the output is turning at a different speed than the input so it is still a "differential" drive in a sense. ;)

Sorry, I couldn't resist. :bmw:

[zippy_gg]

The final drive seal was going out on my 05, and replaced under warranty before it got to leak as much as yours.