• Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password.

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?

  • Beginning April 1st, and running through April 30th, there is a new 2024 BMW MOA Election discussion area within The Club section of the forum. Within this forum area is also a sticky post that provides the ground rules for participating in the Election forum area. Also, the candidates statements are provided. Please read before joining the conversation, because the rules are very specific to maintain civility.

    The Election forum is here: Election Forum

Spline Lube: How much time the first time?

stanley83

New member
I need to check/re-lube the splines on my '75 R75/6. This will be a first for me, how much time should I set aside for this task?

TIA,
Justin
 
That depends a little on your mechanical skills. It can be done in around 2 1/2 hours to 3 hours. First time maybe 4 to 5 hours... as with most things, taking it apart is usually easier and faster, the actual lubing is a snap (once you have your brush cutomized and longer), but the "buttoning up" takes longer, especially the MM work to get the rear tire centered again.

Take your time, don't rush!! Maybe do this on an Airhead Tech Day in your area for the first time, to learn some of the "short cut" and "Dah" moments...
 
The last one I did I only slide the back end of the bike back about a couple of inches. The full method is to remove the transmission.

I did mine over a weekend, part one day and part the next. The first day, I just organized and moved things back and gained access where needed. The second day, I cleaned things up, lubed the exposed splines, and slid everything forward. Torqued things down and went for a ride.
 
Tech Days

Maybe do this on an Airhead Tech Day in your area for the first time, to learn some of the "short cut" and "Dah" moments...

Massachusetts seems to be sorely lacking in these events. If I had a garage at my house I'd love to host one. I have access to a nice location in central NH, and would I'd be willing to host one there if there's enough interest.

-- Justin
 
Consider posting a question in the regional forum...see if other's might be interested as well. Get all the tech stuff done before winter sets in!!
 
According to the Clymer's manual, the end of the trans pushrod that contacts the pressure plate should also get a dab of lube. Doesn't require full removal of transmission, but it does mean that you have to do more than just expose the splines. YMMV.
 
According to the Clymer's manual, the end of the trans pushrod that contacts the pressure plate should also get a dab of lube. Doesn't require full removal of transmission, but it does mean that you have to do more than just expose the splines. YMMV.

From memory, that is still possible even if you just pull the tranny/swingarm back.
 
I've got a heated garage, so projects such as spline lubes are wintertime entertainment for me. There must be someone in your area with a love of airheads and a garage. Ask around. Check the Anaonymous book. Start a thread in the regional forum. Check the Airheads site.

The splines won't be your last need for working space or down time.

You'll want to extract the throwout bearings to clean, check, and lube. Note that the clutch arm pivots on a shaft that's held in place by a somewhat flimsy clip. At the suggestion of the gurus (I can't remember whether Paul or Matt) I replaced the pivot shaft/clip with a 6mm bolt, held securely in place with a nylock nut. Insurance against breaking the tabs on the transmission case.

While doing the splines and throwout bearing, it's a good time to lube the clutch cable pivot barrels (both ends), swing arm bearings, rear brake pedal pivot and rod end barrel, and squirt a little WD-40 on the sliding rod on the rear brake switch.

pmdave
 
Manicmechanic, BE, and myself gang banged a spline lub on an R80 ST a few years back. Done in less than an hour with 3 competent mechanics. If your'e by yourself with out experience, first time, I'd budget 8 to 10 hours. Each of us has done it "the first time". fear not and ask questions, you'll need a special tool for the swing arm lock nuts. (27mm with the outside wall ground downto fit in the frame boss) best practice is to use new bolts for the U-joint flange, but you can slide the whole drive line back enough to get to the splines .
 
I did mine for the first time a couple of months ago. It took 3 1/2 hours not counting the time it took to grind down the big socket for the swing arm. The actual lube time on the splines took took maybe 60 seconds.
 
Massachusetts seems to be sorely lacking in these events. If I had a garage at my house I'd love to host one. I have access to a nice location in central NH, and would I'd be willing to host one there if there's enough interest.

-- Justin

Justin:

Tech days don't really work that way...

What you should probably do is announce your tech day through your states Airlist and via the Airhead Newsletter to let everyone know where and when and where your tech day will take place. (A grill, a few hot dogs and some cold beer helps!)

If you specify it in your announcement, Airhead members will contact you to let you know that they'll be coming. Perhaps only one guy will be interested but you'll probably be inundated with participants.

All I know is that every Tech day I've ever been to, has had more than enough Airheads show up to make it a great party, where a lot of Airhead type work gets done and new friends get made.

It's just like at a Jr High School dance. You have to take the first step!
 
Last edited:
Took me most of a day the first time. I also did the throwout assembly,swingarm bearings. You do not need to completely remove trans. Since you disturb carbs, you may have to resynch them, unless you use a most gentle touch. Best to assume resynch is part of task as far as time goes.
 
Sockets, 27mm:)

Some companies sockets fit without grinding on them, so its a search for the right one at times. I think "Easco" is mine, but its been years. Grinding works too, but options exist if you're lucky enough to find the right socket company. You're always better to drop that tranny all the way, if you're IN that far already, why not. You get to clean up and inspect it soooooo much better this way. Another 10-15 minutes gets you a better job,imo:). A good clutch inspect is also a good idea, if its been years and lots of miles, even the rear main seal, oil pump and all else in there needs a look see. The newer style teflon main seals are about 500% better than the original seals. Go slow is great advice from others above, so take heed:). Randy
 
Stan - in Needham here, have the tools, happy to help. Garage not heated, but attached, so no real seasonal constraints. It is about a half day job, taking it easy. Don't recall upsetting the carbs at all.
 
Spline Lube - Done!

Well, I finally got around to doing the spline lube. Not nearly as involved as I had feared and should take much, much less time next time around. FWIW, chopsticks work really well as acid brush extenders.

I did discover that the seals on the clutch control were shot and need to be replaced, so I'm not out of the woods yet. Everything went back together easily without any extra parts and I got in a short test ride before the snow began to fall.

Thanks for the advice,
Justin

p.s. Any locals who want to borrow my swing-arm socket, contact me via email.
 
swing arm socket

Jeff Trapp at Nortwoods Airheads sells the pre-ground socket for $14.50. He'll also sell you a small amount of proper lube. Check out his website as he has lots of airhead tools. I've purchased most of them and all have worked fine. He's a great help to any airhead owner.
 
The first time I did mine I borrowed a swing arm nut socket that had been ground down to fit. I took everything apart and removed the transmission as I was doing some other work.

Along the way after that I bought a Crapsman socket and checked the fit in one side of the frame. It fit into the hole in the frame and onto the nut so all I did was have a machine shop grind the open side flat. I put the socket in the tool box awaiting a need for it. When I did the spline lube the second time I found that socket fit into one side of the bike but not the other so this delayed the job until I ground the circumference down.
 
My first time I also had to replace the clutch, so I spread it out over (2) days and took it slow. I documented my steps with pictures and words and can email a PDF to anyone who wants it. This was on a 1982 R65, but many of the steps are similar if not the same on other vintage airheads. I pulled the swingarm back and completely removed the transmission in the process.

Mike in NH
 
Back
Top