Hi guys 

I just installed a new seal at the final drive since it was leaking. But it still is leaking... Yes I mounted the seal correctly and the inner lip is not folded. 
The seal is not original, it is from tills.de and made out of viton and I have ordered a couple of seals made of viton with out any problem. 

Right now i need some different parts and I would like to place the whole order from tills.de. But should I go for an original seal instead? Tills.de only offers viton seals.

Is the surface the seal runs on flat and clean, that is not marked in any way or worn due to the old seal.

RicK G wrote:Is the surface the seal runs on flat and clean, that is not marked in any way or worn due to the old seal.

The surface did have some surface rust on it where the old seal did not cover, but I carefully scuffed off the surface rust with 600 grit. When I was almost down to the surface I carefully used 800 grit at last. I have experience with polishing from work and there are no scratches which should prevent it to seal tight.

I am able to get a thin piece of plastic under the outer lip on the seal, so I guess something is not right

I would measure the diameter of the sealing surface and check the seal matches because that clearance is not right.

Tommy2305 wrote:The seal is not original, it is from tills.de . . .

Is the seal you purchased the one that is offered on this page I viewed today?

To measure the seal I have to pull the housing apart once again, would rather avoid that. Does the 8v and 16v bikes have different diameters? 

Yes the link you provide is the one I ordered and I'm considering ordering once more.

Is this the right measurements?:  85X110X10mm


(found on this website: https://www.mc-importen.dk/reservedele/article/630344/10106020300 )

Tommy2305 wrote:Does the 8v and 16v bikes have different diameters?
Yes the link you provide is the one I ordered and I'm considering ordering once more.
Is this the right measurements?:  85X110X10mm

The seal fits both 8V and 16V models. The dimension you give is the same as provided by MaxBMW's parts fiche in the USA. The part number at tills.de is the same as Max's. The coloration of the seal on the tills.de site differs from the color of the seal you are holding in the photograph. That might be a function of monitor color choice.

Where did you get information that the tills.de seal is Viton? Did you heat the cover before bolting it on?

This would appear to be the seal spec'd for most of the K-bikes.
Why not just try one form a local bearing shop?
Seal material shouldn't make any difference to the size

Shaft seal     85X110X10     1             33121241938

A word of caution, I have seldom found that seals fail without some other factor such as vibration from a bearing that is past it's best before date. So I have found it best to change the bearing and avoid re-visiting the seal in the near future.
Just my experiance

Well I read somewhere the seal should be viton, but actually it doesn't say in the product description, I might have made a mistake. The cover was heated slightly for easy fitment over the bearing, I could still touch it with my bare hands. 
The color was also brown on the seal I fitted, I guess it's just the light which makes it look black-ish. 
But good to hear it is the same diameter for 8v and 16v, that's what the description says.


The bearing seemed all right, and I might go down and check at the local bearing store, a actually knows someone who maybe can supply one with those measurements.

Let us know how it all works out. I would love to know if there is a difference in dimensions of some of the seals. It would make the rest of us pay attention when purchasing new ones.

Unfortunately it has made extra work for you by the look of it.

Can you confirm that there was a spring in the rear of the seal? In seals of that type, the inner lip holds the oil, while the outer lip keeps the dirt out. The spring forces the inner lip against the sealing surface.

It's also possible that the inner lip has been distorted when you assembled the housing. Can you take it apart to inspect the condition of the lip? Did it pick up a bit of dirt or was it distorted during assembly? A bit of Vaseline on the sealing surface before assembly helps the seal slide over the hub.

As far as I know, there is no dimensional difference in seals made with Viton vs. other materials. 85mm is 85mm regardless of what the seal material is.

Well I'm not able to measure the old seal since it folded when I pulled it out. It can measure what ever you want it to be.. Yes the spring sits as I should on the old seal, and I did lube the lip before installing. 
The make seems to be: Jago 85x110x10

I measured the new seal to be around 83.3mm around the inner lip, but this lip Is smooth without any riddles and it has no specific rotation. Also the outer lip is around 85.3 but it is really hard to measure since the rubber is very soft, but it seems big!
I bought it at the local transport industry store, with the measurements 85x110x10. A lot cheaper than oem! Unfortunately I did not have the time to fit the new seal today, I only had time to pull out the old one.

Another thing, is the hub supposed to measure 84.65mm???  seems like a odd measurement, why not 85?

Left field suggestion..
...but I have just stripped and cleaned a Mitutoyo digital vernier after discovering that it was reading off....and had been doing so for some time when it finally dawned on me 

- it still zeroed fine, but the reading 'missed' around half a millimeter near the 8mm point....

This caliper is from work. I'm a toolmaker and it is calibrated 2 times a year and measures very precise, otherwise I'm not able to work 

Just an update: The new seal seems to do the trick. No oil on the rim or brake rotor so the rear brake actually works 

I have had 2 final drive fails in 11 years. Both in fact resulted from failing big bearings. Seal fails even before you feel play in that bearing.

I have 2 spare final drives I got that have failed seals so they are getting big bearings too.

I just changed my '85 K100RS final drive shaft seal using your photos, etc. Pretty easy, I drilled the seal (ring is metal) and used grabber screws to pry out the old seal. New one went in OK and seems to be holding. Seal was $50 from Max BMW. 3 days for priority mail. Cheers!