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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: slipring on May 25, 2015, 04:51:03 PM

Title: K75 Final Drive Unit Oil
Post by: slipring on May 25, 2015, 04:51:03 PM
Hey all.  I'm starting to go through my K75 for the first time (this bike is new to me as of last fall).

After removing the final drive unit and cleaning the splines, I see that there appears to be gear oil outside of the final drive case, beneath the splines (see photo). 

Q1.  Does this necessarily mean that the oil seal needs to be replaced? (see item no. 25 in the exploded ass'y diagram)

Q2.  Does brown-ish color of oil pose any concerns?


(http://i172.photobucket.com/albums/w36/theidrathers/gear%20oil%20leak%20x%200.33_zpsx3zrdg9k.jpg)


(http://i172.photobucket.com/albums/w36/theidrathers/final%20drive%20exploded%20x%200.5_zpsv5ob36s8.jpg)



Thanks.
Title: Re: K75 Final Drive Unit Oil
Post by: RobP on May 26, 2015, 11:50:22 AM
What grease was used ON the splines for lubrication?   Some types of grease will separate and leave oily deposits. 
Title: Re: K75 Final Drive Unit Oil
Post by: slipring on May 26, 2015, 01:17:29 PM
Rob,

Not sure what grease was previously used for spline lube (bike is recently new to me).  I cleaned the splines to assess overall condition (answer, I believe, is "excellent").  I also cleaned the silver part of the final drive casing (around the splines).  The oil that's visible in picture, "puddled" a day or two after my wipe-down. 

Would it be possible for previous grease to separate and have the oily portion get between items numbered 22, 23 and 24 and the oil seal, item no. 25, in the previously posted diagram? 

Note 1.  The final drive unit is completely removed from the bike and room temperature (not warm or hot) gear oil was drained out of the final drive case.  Some gear oil must have remained - clinging to internals.  Note 2.  I've purchased and plan on using Guard Dog GD525, for spline lube, when I get to the reassembly stage

I suppose I could re-fill the final drive with new gear oil and keep wiping the silver casing around the splines and see if the brown-ish oily puddle goes away or starts to change color (i.e. to that of the new gear oil).  Thoughts?
Title: Re: K75 Final Drive Unit Oil
Post by: pallum on May 27, 2015, 01:31:44 AM
My final drive leaked like that for 80k miles. Never got better or worse, and never lost enough between oil changes to make a difference. As long as it's not dripping onto your rear tire I would just keep it rollin'!
Title: Re: K75 Final Drive Unit Oil
Post by: wmax351 on May 27, 2015, 09:34:53 AM
Quote from: pallum on May 27, 2015, 01:31:44 AM
My final drive leaked like that for 80k miles. Never got better or worse, and never lost enough between oil changes to make a difference. As long as it's not dripping onto your rear tire I would just keep it rollin'!

Frankly, having oil in there is probably good!
Title: Re: K75 Final Drive Unit Oil
Post by: TimTyler on January 05, 2016, 01:15:08 AM
Quote from: slipring on May 25, 2015, 04:51:03 PM
... I see that there appears to be gear oil outside of the final drive case, beneath the splines (see photo). 

I always find a little gear oil pooled under the final drive splines. I assume it has leaked from the rear gearbox seal and drips down the swing arm.

I was worried the first time but when I check the oil levels in the FD and gearbox, they are where they're supposed to be.