25 CC

[Bamboo812]

You'll need to remove the threaded ring as well to clean and seal the threads themselves from leaking. This could very well be where the oil is going, bypassing the seal. Use some modern thread sealing compound; Hylomar does NOT work in this application. Cycle Works sells the tools for this job. If I remember correctly, the shaft seal is mounted inside the threaded ring...

[Airbear]

You'll need to remove the threaded ring as well to clean and seal the threads themselves from leaking. This could very well be where the oil is going, bypassing the seal. Cycle Works sells the tools for this job. If I remember correctly, the shaft seal is mounted inside the threaded ring...

Thanks for that extra information, Timo. Makes sense.

[Bamboo812]

Easy Peasy!

[KellyVB 75R90S]

Timo,
Thais what I thought, I read the article on snowbums site atleast 20 times, he also states that the housing MUST he heated in in order to remove/install the the threaded ring. Also I looked on the Cycle Works site and don't see any tools there anymore. have a good link for one.

[tsa]

One of the benefits of being a member of the BMW Club here in the UK is loan access to all the Special Tools the Club has. Currently I'm doing some Final Drive work and have the Threaded Ring tool sitting (almost) next to me. This is what it looks like:

Threaded ring tool 486.jpg (42.37 KiB) Viewed 1585 times

As you perhaps may see, it's (like many of the other "special" tools) not very complicated. As for dimensions, I'd be happy to provide some measurements, but those can easily be taken from the FD itself.

Your problems with the slippery brake shoes is not actually due to the migrating oil itself, but a blocked drain hole that can be seen next to the FD drain plug. This hole is the orifice of a narrow drilling into the space outside the "big" oil seal that sits inside of the FD splines, where the brake shoes live. The point is that when (i.e. not if) oil leaks past the big oil seal, it should be drained out instead of collecting there and eventually be thrown up and around and onto the brake shoes. BTDT, I actually managed to clean off contaminating oil with petrol, acetone and other nasty stuff, which requiered me to glue the brake material back to the carrying shoe again. Been working fine for > 5 years now. Of course, if you do as I did, you may die, therefore a disclaimer: only leave such work to "professionals" or other people who know what they do. You cannot sue me!

The mentioned drain canal usually clogs up with excess grease thrown off the drive splines, and needs to be cleaned out regularly, e.g. every time the rear wheel is off.

[Bamboo812]

Apparently Cycle Works doesn't sell a /5 specific tool. You have to buy a /2 tool and a set of pins, and the big socket, for it to work on a /5; http://www.cycleworks.net/index.php?mai ... l&x=17&y=4

[Duane Ausherman]

The oil can also leak down the drive splines. Know all three paths.

When I read some of snowbum's stuff and know the procedure very well, I still have trouble following his writing. In person he doesn't talk that way at all. I am similar, I talk better than I write.

[KellyVB 75R90S]

My main question is why does this oil get into the final drive so fast? The drive splines have nothing to do with that. It's like there's no seal there at all I did find the tools I need for the job at Cycle Works after all. They will cost be probably $120 with shipping. Going to call the local BMW shop here in San Antonio and see how much it will cost me for them to do the job. (I will remove the FD and take it in) If they are GREEDY and want to charge me a fortune, I will order the stuff myself and do the job. Thanks to all who chimed in. BTW, I did try to clean out both weep holes with a piece of wire. I will also seal the threaded ring threads as you say to do Duane.

Kelly

[KellyVB 75R90S]

Since I started this post I have read all I could about this oil transfer on Duane's site as well as Snowbum's site plus and listened to what all you guys have told me. Well tonight I couldn't stand it any longer and I pulled the FD off and all I can say again is OMG
The nut that holds the input gear on was only on the shaft by about 3 turns, There is also no gasket ring (Part #3 on the fisch) installed after the washer. This has been like this for over 30 years as I have NEVER had the FD off. The input gear and matching driveshaft gear also show no wear at all. How could the nut have even stayed on that shaft so long without falling off No wonder the oil leaks into the final drive! Duane, are these splines in the shaft that the gear goes on the ones your talking about that need to be sealed? (I don't know how to add a photo or I would)
I MUST THANK THE MAJOR for posting that I need to fix this or I would have probably never looked at it. I'm sure it would eventually have come off, causing a lockup and crash Those of you that have NEVER looked at this area of their bikes PLEASE do so.

SO GREATFULL
Kelly

[Airbear]

The nut in mine was found to be only finger-tight the last time I had access to the FD. I have no idea what would happen if that nut actually came off.

Well done finding your problem and a path to deal with it.