[cluainsi]

Hi All,
My bike is a 2003 K1200lt with 50k Km.

I wonder if anyone can help me. I had a clutch slave cylinder failure which I replaced myself. That now works fine. While doing this I noticed that the gear box drive shaft output seal was leaking some so I decided to change it. Reassembled everything and went for a long ride around the north of Ireland (I live in Limerick, Ireland) after 3 days I noticed that I had gear oil coming from the rubber gaitor between the final drive and the swinging arm. On investigation I found the oil lever low in the gearbox and had to top up to get home. When I opened the gaitor at home I had a large amount of gear oil in the swing arm. The new seal which I replaced on the drive shaft is leaking much worse than the original.

I decided that I might have done something wrong ( or I had a faulty seal) so I installed another new seal. Both seals were supplied by BMW through Motorworks in the UK and look identical to the original except red in colour instead of black.

On Sunday I went for a spin of about 200Km and this morning the result is the same. Gear oil in the swingarm again.
What have I done wrong? Has anyone out there experienced a similar problem?
What is the fix for this.
Please help as I dont know where to go next.

 

[casualemt]

Had a problem like that on a rear main seal on a VW van, replaced the seal twice, both times leaked badly, discovered I was installing the seal backwards....the third one did the trick!!

 

[cluainsi]

Seal installed in same direction as original, lip and spring towards gearbox. Seal tapped home with deep socket into groove. Is it possible to push seal too far in?

 

[K100Dennis]

Make certain you are not caving the seal body in by using the socket. The steel seal casing under the outer covering won't take much impact to distort and this will affect the seal's ability to function. Also make sure it is not "cocked" when driven in, and that there is nothing for the inner lip to catch on and get damaged (like a shaft step). If this is the case you can carefully wrap the shaft with some pvc tape, push the seal in the remove the tape from under the seal. Also need to be certain you haven't caused a scratch on the shaft when removing the old seal. Take you time and very thoroughly examine everything. Hope this helps.

 

[cluainsi]

Thanks for your replies, I used the absolute minimum force requires to seat the seal (did not require a lot), Socket I used is a deep 27mm used for injector removal on some cars and is just smaller in diameter than the seal. The first new seal used had absolutely no distortion when removed except for the gouge left by the screwdriver on removal. Outer face of seal still flat. The screwdriver used for removal never reached the seal lip position so I could not have damaged the shaft as all force used to remove it was away from the shaft. The shaft has no lip to catch the seal on the way in and very little resistance was felt on the shaft until the seal contacted the gearbox casing.

 

[casualemt]

in the bmw manual, a sealing washer is mentioned behind the seal, in front of the bearing, it has a warning to be careful not to damage that washer when removing the seal...don't know if it has any effect on the seal if the washer is damaged, but might be something to check as long as you are in there..

 

[saddleman]

If the seal is installed to far in it will leak. The seal you got from the dealer is the updated seal with better material. Sometimes the transmission housing can get nicked removing the old seal. If that happened you can drain the gear oil & clean the area with brake clean until no oil is leaking out. Add some silicone to the outside diameter to the seal. Install the seal & let it cure for 24 hours. I can get a measurement of the seal depth installation for you this afternoon when I get home from work.

 

[cluainsi]

Thank you saddleman. Of course I did not measure the depth when I removed the old seal, but at a guess I would say that the new one is only slightly further in possibly less than a millimter.

 

[jzeiler]

That seal is a tough one to set just right. I re-built a tranny for another member and had to re seat the darn thing three times before I was happy with it and then 3 months later it started leaking on him.

Also oil only the sealing lip not the outer part of the seal - it must be installed dry.

 

[saddleman]

My measurement from the output shaft to the seal shows 28.00mm. This is the best I could do with a pic using the camera with one hand.

 

[cluainsi]

Thanks again saddleman. I will check my measurement tomorrow.
Can this seal be removed without damage for reinsertion at the correct depth?

 

[1dbweldor]

The only way to remove the seal without disassembling the tranny will ruin the seal. Unless you're better than me. I always put silicone sealant on the outside of these seals to install. Which will lubricate for installation and then seal when cured. Check the depth real close, My money says that's the culprit.

 

[rattler50]

If you've left any kind of scratch on the inside surface where the seal goes it's a good idea to use silicone. I also put a little Vaseline on the inside of the seal to keep the spring in place when I hit the seal. Sometimes they'll jump out. Covering it with Vaseline keeps it steady. I drive seals every day. It's my job..........

I'm replacing this very seal this weekend and drilling the weep hole.

 

[Rocketsled]

I drive seals every day. It's my job.

Context is key!

 

[cluainsi]

Thanks to everyone for your valuable help. Today I removed the swing arm etc for the third time and could clearly see Gear oil oozing from between the shaft and the new seal even with the bike not started. Removed the seal and examined everything and I have no damage but I noticed that the shaft diameter increases quite quickly just inside where the seal sits, therefore by pushing the seal too far in the lip reaches this section of shaft and leaks badly. I inserted another new seal and this time only just recessed it using the measurements from saddleman in an earlier post. the distance is between 27 and 28 mm from the end of the output shaft. The 2 seals the leaked were recessed just a couple of extra mm. Oil seepage has now stopped and to be extra sure I ran the bike in 3rd gear for 15 to 20 mins before I inspected the seal and reassembled everything, hopefully for the last time . No leakage now thank God.
The moral of the story is, measure depth etc of old seal before removal. :bmw: