Dry Splines

[Dave 2]

Hello, Today I removed the transmission from the engine and here is what I found, very dry no grease whatsoever, and lots of fine rust dust which I guess is from the splines. Although they are dry, to me they look like they are in acceptable condition. I would like to know what others think. Another question is what are the symptoms of having dry splines? I have thought that the bike was shifting harder, or clunkier than I remember my R/60 used to do, could this be because of the dry splines? When I drained the transmission fluid there was a small amount of a very fine "paste" on the magnetic plug, I think that this is normal. Do any of you think that there is any reason for me to open up the transmission? Thanks, Dave 2

[Bob_Roller]

The clutch splines look good, but the picture of the transmission splines doesn't provide a clear enough look at the splines .

Is there a 'step' in the splines closest to the seal where the clutch didn't touch them ?

[Dave 2]

Bob, I'll take a look and put my camera on the tripod to try and get a better picture, Thanks Dave2

[Barry]

Splines look OK to me. I don't think you have anything to worry about and you should feel an improvement in the gear change when they are cleaned and lubed.

A small amount of smooth grey paste is normal. I changed my oil recently and there was just about enough to fill the recess around the magnet which is very little really and if anything less than previous changes. The box has only done 14000 miles though so maybe it's just run in.

In thinking about the paste it's tempting to assume there might be none. On the other hand our gear change can be noisy on down shifts and you can't generate that metal to metal contact noise without some small amount being worn off the dogs over time.

[montmil]

Yo, D2...

The splines should have sorta squared-off shoulders. Some wear is to be expected but your splines do need to be cleaned up and have a dab of Honda Moly-60 applied.

The trick with the moly grease is to use just enough. Too much and the grease will be flung out and contaminate the clutch friction disc. Too little and, well, you're already experiencing hard shifting.

Apply a thin but complete coating to the splines on the male/gearbox  teeth. Temporarily install the trans and withdraw, checking for excessive squeeze out.

Hopefully, you'll be OK. No one wants to open a gearbox.

Monte

[azcycle]

You know of my recent stripped-spline issue. I do remember shifting becoming more difficult before the splines went kaboom. Your clutch splines look good to me, but I'm far from an expert. Compare them to how mine were.  

You can see the tiny "step" that Bob refers to in this photo of my original transmission with damaged splines:


Good luck!
And of course the badly stripped clutch plate:

[Rob Valdez 79 R65]

Dave, everything that has been said is good.
I just want to emphasize that you put the moly-grease on the gearbox spline teeth, but DO NOT put any grease on the splines on the clutch disk.  That is the grease that gets pushed off.

And put a small dab of moly-grease on the tip of the push-rod.  

It doesn't sound like you need to open the gearbox for anything right now.
You might want to check out your throw-out bearing if you haven't already.

[nhmaf]

+1 for taking the throwout assembly apart for cleaning, inspection, and a bit of oiling, as well.
The bearing in there is lubed by slight oil migration from the gearbox along the pushrod, but until that starts to happen, you can't run the bearing dry.  So, I pre-soak the bearing in fresh gearbox oil and "paint" some oil on the pushrod itself when re-inserting it.   Be careful with removing the rubber "bellows" as the spring inside can tear the rubber if you let it "sproing" out too quickly/forcefully when removing the actuating arm on the back cover of the gearbox.

When the clutch disk splines strip, as they did for me and azcycle, I think that BMW had hoped that the softer friction disk metal would sacrifice itself without incurring damage to the gearbox input shaft.  Well, it doesn't quite work that well in practice.   My old gearbox splines (which look just like az's) *might* still work for awhile, but with the tips of the splines ground away, they are already working with much less surface area than they should have, and will / would more completely self destruct in time.  So, rather than keep that time bomb going, replacing the partially stripped gearbox splines are highly strongly recommended.   Your splines appear to be OK, just clean them and lube as Monte and Rob indicate (a bit of Moly60 on the tip of the pushrod, where it goes to push on the center of the diaphragm spring, will help reduce squeaking.   IT is also recommended to put a thin schmear on the back side of the pressure plate where the fingers of the diaphragm spring press against it.    I have a whole article (With pictures) of replacing the clutch parts on the forum here somewhere.

[Dave 2]

Thank you all for your pictures and advice. I just got a few minutes to take another picture and post it. I'd say that these look fine. although I need to clean them. What I understand from all of you is that I do not apply grease to the "female" splines on the engine/clutch, only on the male spline. I fit them together and turn the gears then remove the transmission and wipe of any excess grease. I should carefully remove the  bellows to control the sproing, and clean and cote the rod and bearing with fresh gear oil. Then put a schmear on the back side of the pressure plate where the fingers of the diaphragm spring contact the plate. [smiley=bmw_smiley.gif] One other question is that you all recommend Honda moly-60, but my dealer sold me a grease called SIG 3000 Super Impact Grease. Manufactured by The Wurth Co. It also has the name "saBesto" . Have any of you heard of this stuff? Thanks for all your help. Dave2

[montmil]

Hey, D2

You should be just fine with the Wurth material. IIRC, that's a BMW recommended grease (?).

http://www.wurthcanada.com/en/webkit/produkte_1/new_product/2011/04.2011%20-%20SIG%203000%2022%20kg.pdf

Monte

[nhmaf]

If the SIG 3000 is like the Wurth 3000 grease, it is good stuff, and quite tacky/sticky (very good in this application).   Look to see if it has at least 10% Moly (molybdenum disulfide) content.  IF it doesn't have at least this much, what I would do (and what I now do) is to mix a bit of it in with equal part Honda Moly60, which is about 60% moly, and then put the mixture on.   Honda Moly60 is good stuff and works pretty well, but it doesn't provide a sticky enough coating to resist corrosion over long term.     Mixing the (2) together gives you plenty of Moly protection for high-force/stress/sliding interaction, and the sticky grease part help provide a corrosion resistant coating.   This is also what Paul Glaves and other airhead gurus do, so I figure that I'm in good company on this suggestion.

[Dave 2]

Very Cool Information 8-) Thanks Monte and nhmaf. I think the Wurth 3000 and the Sig 3000 are the same thing. There is no Moly...in the Sig 3000. The parts man at the BMW dealer said that it is very sticky and to not use it to grease bearings. I like the idea of mixing the Honda Moly with the Sig 3000. Thanks for all your insights it is so much fun to learn all the stuff you need to know to do this restoration work. [smiley=bmw_smiley.gif] Dave2

[Rob Valdez 79 R65]

As long as you have your gearbox sitting there, grab hold of the input shaft (splines) and push the shaft in and out, checking for fore/aft play in that shaft.
There should be a small amount, but not too much.

[Dave 2]

Hey Rob, I just read your post, so out to the Garage I went to check the freeplay I can detect none, forward/back and side to side. Everything  feels like it is turning smoothly, (although I don't have a stethoscope two hear the movement) I have nothing to compare in terms of my experience with transmissions, but this feels fine to me but should it have some freeplay? I was also wondering if I should replace the Throw-Out Bearing since I have the transmission out and the bearing is pushing 30 years old? I think I can tell if the bearing is bad but I'm not sure. Rob I was looking at a past post of yours with a link to your photo albums 8-) nice pictures, although your bike on it's side was a bit harsh. Dave2

[tvrla]

If the throw-out bearing looks good (no pitting or galling - just a smooth race and nice shiny round balls), no reason to replace. And the transmission sounds good too - they're shimmed at the factory to have a slight amount of play, just enough to rotate freely. If it's got more than that, it possibly wasn't shimmed properly in the first place.

So nothing to worry about there!