Friday, January 17, 2014

Opportunistic Spline Lube

Airhead Beemers use a dry clutch and the spline on the transmission input shaft needs to be greased every couple of years. I believe that I did it last year since I had gone on my road trip the previous summer. Since all the other parts and pieces were removed, it was a simple task to remove the clutch throw out lever, two transmission/engine mounting bolts and the two rear swing arm pivots. Then the whole transmission/driveshaft/rear wheel assembly was moved back until there was about an inch of space between the transmission and the engine.

This is the view looking at the transmission input shaft n.b. the shiny areas and how it seems pretty dry. No major wear but this maintenance was needed. The splines shown fit into the clutch disc located on the left. Kind of dirty but not too bad for 31 years and 75k miles. The front of the transmission is on the right.

According to "experts" on the forums, the preferred lubrications is Honda Moly 60 though I mix it with some arctic grade grease to make it a little tackier. I brush it on the transmission input spline with a disposable brush stuck on the end of a chopstick. I picked up this tube in 2008 and have used about a quarter of it since then. It is also used on the rear wheel splines and the gear drive for the throttle cable.

This is after the application. Not much is needed. The transmission is simply slid back into place and the transmission mounting bolts reattached.

The swing arm pivots were cleaned and reinstalled taking care to re center the rear swing arm in the frame. Since it is very difficult to actually measure the gap between the body of the swing arm and the frame, I simply stick a fingertip into the gap and measure by touch. Then double check by eye before torquing the pivot lock nuts down. Total time for this entire maintenance task was 15 minutes due to all of the other pieces already having been removed. The first time I performed this task it took the better part of a day.

The new alternator did not arrive yet though the USPS tracking site says it left Anchorage Wednesday morning. I'm expecting it today. This was another attempt at blogging directly from the phone. The only negative is the pictures link into some Google+/Picassa no-mans-land with pages and pages of all of the pictures that I've used on the blog instead of the specific photo. I modified the href tags but it is still not what I want. After all aren't these fascinating photos that you HAVE to see in vivid detail ;-)

Maybe blogging directly from the iPhone is an unrealistic goal...
- Posted using BlogPress from my iPhone


Unknown said...


I clicked on a photo and Google+ wanted me to tag my face on all my photos and it went to Google+ (not Picassa) with all your other photos

My spline was done this Spring before my trip and it looked dry but there was trace of some white stuff on the splines

Can't wait to find out about your long distance plans this year. Seems you are getting everything prepped up

Riding the Wet Coast

Erik R said...

That reminds me, I need to pick up another tube of Moly60 one of these days. I use it on the FJR splines and all suspension links and pivots.

RichardM said...

I think that is a result of a limitation with the iPhone app. I keep hoping that I'll find a way or one that works as expected instead of all this Google+ weirdness.

No solid plans but I'm thinking of riding down to MT then over to MN for the MOA rally then maybe to L.A. for another reunion then back. Just thinking...

RichardM said...

Great stuff. I picked it up at the Honda/Harley/BMW shop and they couldn't find any. A mechanic came out and told them that it was in their shop supplies.

Unknown said...


Amazingly the local Honda dealer did not stock any. I had to pay up front and special order it. Up here it cost about $40. CDN

Riding the Wet Coast

redlegsrides said...

Spline lube only every couple of years? I've heard mileage figures ranging from 8000-15000 depending on the airhead SME. I've settled on every 10K miles, and yes, fail to do this lube and you will strip the splines and incur a costly transmission repair job! Been there, done that.

Now that I've done it once, I no longer "fear" this maintenance task. :)

RichardM said...

Wow! I think the Harley dealer charged ~$10.

RichardM said...

I think that's what I remember reading on Snowbum's site is 12k to 18k miles for 1981+ bikes due to the plated input shaft. More often for older bikes. For me, that is about every other year. I was doing it at the same time as I changed the brake fluid but I think that's supposed to be every year.

Pretty straightforward task after you do it a couple of times.

Coop a.k.a. Coopdway said...

I've been away and it seems I've missed a lot here Richard; our Marine is home. I'm busy today with other motorcycle activities but will return and study more closely your recent posts. Thanks for sharing!

BMW HACKER said...

For "gapping" the swing arm bolts, I use a small "Allen" or "Hex" key wrench. Choose one from your assortment and just make it equal to both sides...but then by "touch" is surely just fine too.
A "little" lube goes a long way on a spline lube. I use the red "BMW" grease. Bought a tube 20 years ago and still haven't used it all up yet.