My Spine Report - Add it to your stats...

[87K75S]

The clutch input spline was opened up today on my new-to-me -87 K75S.  It was very dry but showed very little, if any, wear.  The middle spline was also very dry but in great shape.  The RD spline had some lube and was also in very good condition.


I assume the RD was lubed at least once before.  Who knows.  I have no record of it.  The Service History book has a BMW Inspection II on 7-7-94 at 10,023 miles.  I'm going to assume that that is the last time the clutch/input shaft was done. The bike currently has 21,000 miles.  I see that the Service History book says:

Clutch splines / Input shaft
This vital area must be lubricated once a year. If vehicle is used in costal areas or other high humidity areas this service must be performed bi-anually.

It'll be done now though and I'm going to call it good probably for the length of my ownership as I don't put a whole bunch of miles on my motorcycle.  I'll continue to do the RD (and other end of the DS) with tire changes.  FWIW, in my 300 miles of riding the bike, I did experience downshifting difficulties numerous times.  Hopefully that will be cured!

[technostructural]

Clutch and input splines once a year? That seems extremely excessive. I thought it was a 40,000 mile service, or something like that.

Now, the final drive and driveshaft splines should probably be done annually. Those are not so bad though. I believe even for those, the recommended service is only when you are changing the rear tire.

[Laitch]

Clutch and input splines once a year? . . . thought it was a 40,000 mile service, or something like that.
Now, the final drive and driveshaft splines should probably be done annually. . . . I believe even for those, the recommended service is only when you are changing the rear tire.

Sounds about right to me. If I weren't already using up a set of tires per year, I'd be changing rear drive oil and lubing the rear drive input spline annually anyway. Gear oil isn't too costly and the procedure is uncomplicated.

[technostructural]

I'd be changing rear drive oil and lubing the rear drive input spline annually anyway. Gear oil isn't too costly and the procedure is uncomplicated.

Good call on that Laitch. I confess that it has slipped my radar for the past year or so. I should probably replace it!

Now to start reading the abyss of threads about "the right gear oil to use"...  :computer-noworky:

[pinhead]

Its a myth that the engine to trans splines need periodic lubrication as the drive shaft splines do.  Lubrication at the time of clutch replacement is all that is necessary.  The trans is bolted fixed to the engine and doesn't move unlike the drive shaft splines that accommodates the movement of the rear drive suspension.  If such was the case, then 2 wheel drive cars and trucks with clutch would need the same, but they don't!  Think about it.  The unsavory experience of having your drive shaft splines burn up from lack of lubrication has created a hysteria with the BMW shade tree mechanics that all splines on the BMW need periodic lubrication.  Cars and trucks with rear wheel drive and drive shaft splines have grease fittings for periodic lubrication.  The flying brick BMW engineers thoughtlessly left that out and no means to lubricate except for disassembly.  Every time you replace rear tire, disassemble the drive and lubricate the splines.  A simple grease fitting with access would have alleviated that need but BMW didn't consider it necessary.  Or more sinister, a planned need for service by your friendly BMW dealer. 

[Laitch]

 :tinhat2

[johnny]

 ˌənˈkämpləˌkādəd

[stokester]

Its a myth that the engine to trans splines need periodic lubrication as the drive shaft splines do.  Lubrication at the time of clutch replacement is all that is necessary.  The trans is bolted fixed to the engine and doesn't move unlike the drive shaft splines that accommodates the movement of the rear drive suspension.  If such was the case, then 2 wheel drive cars and trucks with clutch would need the same, but they don't!  Think about it.  The unsavory experience of having your drive shaft splines burn up from lack of lubrication has created a hysteria with the BMW shade tree mechanics that all splines on the BMW need periodic lubrication.  Cars and trucks with rear wheel drive and drive shaft splines have grease fittings for periodic lubrication.  The flying brick BMW engineers thoughtlessly left that out and no means to lubricate except for disassembly.  Every time you replace rear tire, disassemble the drive and lubricate the splines.  A simple grease fitting with access would have alleviated that need but BMW didn't consider it necessary.  Or more sinister, a planned need for service by your friendly BMW dealer.

I can't give you an engineer's response to the clutch splines need of lube but in my experience it is needed more often than when the clutch is replaced. 

My '93 K75S was suffering with frequent false neutrals especially when down-shifting.  I read on this forum that it was a sign of a dry clutch spline so I performed the duty and it went away.  It is also well known in the Airhead community that the fine splines will corrode and strip if this is not performed periodically.

Why it is needed on our motorcycles and not on autos, I can't answer.

[schrocketeer]

Yesterday did my final drive splines. 47k miles on an '85 k100rt. The attached pictures are what it looked like when I took it apart. I used a pick to clean out the valleys, and carb clean to clean out the old. Then I applied new grease.
Since a previous owner had kept the splines in this good of shape, and the coolant was nice as clear, I'm not pulling the transmission to do the clutch side yet. I'll probably do that at rear tire change time.
The Chris Harris "final drive pre-buy inspection" video on youtube was very helpful.

[pinhead]

I can't give you an engineer's response to the clutch splines need of lube but in my experience it is needed more often than when the clutch is replaced. 

My '93 K75S was suffering with frequent false neutrals especially when down-shifting.  I read on this forum that it was a sign of a dry clutch spline so I performed the duty and it went away.  It is also well known in the Airhead community that the fine splines will corrode and strip if this is not performed periodically.

Why it is needed on our motorcycles and not on autos, I can't answer.

This is where we agree to disagree.  I am sure you had valid clutch/transmission problems but I still am skeptical on its relation to the splines.  I talked to BMW service department and was told no special lubrication is needed for engine/trans splines other than when clutch replacement happens.  And I will be the guinea pig on this one.  I refuse to disassemble my trans/engine for spline lube.  Bike has 84,000 miles on it now.  No problems yet.  I do lubricate the drive splines every tire change. 

[Chaos]

with mine I had the transmission out for a bent shift fork around 90,000 miles.  Never had any shifting problems and I think we lubed the splines.  That was 100,000+ miles ago and it still shifts fine.  I have seen some with shifting issues early on, I think they might have been improperly lubed during conception.

[Laitch]

I refuse to disassemble my trans/engine for spline lube.  Bike has 84,000 miles on it now.  No problems yet.  I do lubricate the drive splines every tire change.

How many miles have you put on it?

[stokester]

This is where we agree to disagree.  I am sure you had valid clutch/transmission problems but I still am skeptical on its relation to the splines.  I talked to BMW service department and was told no special lubrication is needed for engine/trans splines other than when clutch replacement happens.  And I will be the guinea pig on this one.  I refuse to disassemble my trans/engine for spline lube.  Bike has 84,000 miles on it now.  No problems yet.  I do lubricate the drive splines every tire change.

With my Airhead experience and the known need for periodic clutch spline lube along with the thread on this list regarding false neutrals I found the clutch spline lube took care of the issue.  The procedure was not difficult but was a bit time consuming and I was pleased with the results.

As with all recommendations regarding my Airheads and K75Ss I always lean to all those who have been there before and remember it is my motorcycle and I choose what I want to do.

[87K75S]

My false neutrals are better but I have no way of knowing if I'm just getting used to the bike or the clutch spline was the issue. I can remember on or two since I've had the spline lubed.

Another thing that had me doing bad things was the '04 RT I owned just before I bought the K. That bike liked to have a little preload on the shift lever while upshifting. The K does not like that at all and I just recently figured that out. Upshifting is a little crunchy (?) until the bike is fully warm but it definitely helps to not preload AT ALL (for me).

And just a side note: this bike has used ZERO oil in the 1,500 miles I've owned it. So nice compared to the RT!

[Martin]

Make sure you have adjusted the clutch correctly using the correct procedure.
Regards Martin.

[Laitch]

Make sure you have adjusted the clutch correctly using the correct procedure.

+1   Also, remember to shift assertively. The gear box can handle it. Twinkle-toes are for dancing.  :yes Check the gear box fluid level, too.

Many riders here lubricate the transmission splines at 20K mile to 40K mile intervals, without hysteria. Those intervals should be good enough for a rider who isn't flogging the bike. Some riders like Chaos, who has over 100K miles of K-bike riding and maintenance experience—and pinhead, who has a small fraction that—don't conform to intervals at all concerning the procedure.

You'll find your way.

[Filmcamera]

[size=0px]Make sure you have adjusted the clutch correctly using the correct procedure.[/size]

I did mine this morning, it only takes a few minutes and Chris Harris has a great video showing you how to do it.