My First (Full) Spline Lube

[technostructural]

Hey folks,


So, rather than pollute the "What did you do with your motobrick today?" thread with updates on my spline lubing, I figured I'd just create a thread in the Workshop where I can ask questions about the process. I've done the rear drive and drive shaft splines before, but I haven't tackled these forward ones. I've only had the bike for two years (only one of which I was actually riding the bike). I figured it's time to crack it open and see what we're dealing with.


I finally got the transmission out today (using guide pins made from 125mm M8 bolts with the heads cut off). Here's what I found:





Does the inside of the bell housing look a little oily to you? My understanding was that this was supposed to be dry. There does appear to be a bit of a film, but I can't tell if this is really evidence of the rear main seal leaking or some sort of other oily incontinence from the transmission, or over-application of lube on the clutch/input splines.

Any thoughts on that?


Secondly, why the hell is their so much dirt and grime in the bell housing here. What would cause this? I think this might be sand?





Thirdly, my clutch rod appears to be different than the ones I've seen in manuals and online. Rather than have a cup and a bearing behind the clutch boot, there is this rather strange looking thing:





It appears to do the same thing that the other design does. Is this a newer design? It goes hand in hand with a clutch rod that also appears a bit different than the ones I've seen here on Motobrick and elsewhere:





The input splines seem to be in pretty good shape. I still need to clean them a bit more thoroughly:





Whatever was on them before appears to be pretty black. It could be Honda Moly? I'll be using Staburags NPU 30 PTM for these forward splines and Honda Moly for the rear drive / drive shaft:





Thanks all. Looking forward to your thoughts on some of these questions / observations.

[Laitch]

Looking forward to your thoughts on some of these questions / observations.

Your clutch rod piston is the updated version. The rod and the piston are appropriate. Is the boot in good shape? The oily film on the housing is likely caused by a leaking o-ring or seal. You should remove the clutch pack to find out. Whichever lube was on the splines previously doesn't matter now that you are using the right stuff. Let's have a clear, straight photo of the clutch disc splines, too. Have you viewed the Chris Harris clutch replacement video?

[The Mighty Gryphon]

As long as the transmission is off, I would replace the O-ring.  I've been into two of my bricks, and both of them had hardened O-rings.  One of them leaked pretty bad, the other hadn't started to leak YET.

The rear seals on the other hand, both looked good and had pliable sealing lips that didn't leak.  It probably was overkill to have replaced them.

Pull the clutch, change the O-ring, and look for any oil running down from the lip of the rear seal.   If not, it's your call, but unless it was leaking I would let sleeping dogs snore.   

[technostructural]

As long as the transmission is off, I would replace the O-ring.  I've been into two of my bricks, and both of them had hardened O-rings.  One of them leaked pretty bad, the other hadn't started to leak YET.

The rear seals on the other hand, both looked good and had pliable sealing lips that didn't leak.  It probably was overkill to have replaced them.

Pull the clutch, change the O-ring, and look for any oil running down from the lip of the rear seal.   If not, it's your call, but unless it was leaking I would let sleeping dogs snore.

Thanks Gryphon. I'm inclined to do the same. Which o ring are you referring to?

[The Mighty Gryphon]

#11 on the drawing.  It's under the clutch nut(#8) and spacer(#9) that hold the clutch pack in place.

[technostructural]

#11 on the drawing.  It's under the clutch nut(#8) and spacer(#9) that hold the clutch pack in place.

Thanks Gryphon. I'll have a look today. I don't need to be worried about anything being unsupported with this bolt off? I'll confess that this is about as far into the job as I am familiar by watching videos and reading tutorials.

Your clutch rod piston is the updated version. The rod and the piston are appropriate. Is the boot in good shape? The oily film on the housing is likely caused by a leaking o-ring or seal. You should remove the clutch pack to find out. Whichever lube was on the splines previously doesn't matter now that you are using the right stuff. Let's have a clear, straight photo of the clutch disc splines, too. Have you viewed the Chris Harris clutch replacement video?

Thanks Laitch. The boot is in pretty good shape, but I am planning on replacing it in any event. I will keep the one I took as out as a spare. It's not torn or ripped, but some of the rubber feels a bit old and "gummy", if that description is understandable:





I will grab a clear photo of the clutch disc splines today as well. I have viewed all of Chris Harris' videos on this topic quite religiously, though he stopped at the flywheel and didn't bother with the o-ring seal mentioned by Gryphon. Is there an alternate part for this o-ring? I don't have a dealer nearby, and placing an order for this o-ring alone is going to be pricey =/


More photos and descriptions will be posted this evening. Thanks everyone.

[Laitch]

Is there an alternate part for this o-ring? I don't have a dealer nearby, and placing an order for this o-ring alone is going to be pricey =/

I don't use my nearby dealer. I buy from dealers online.

If the friction disc is oil soaked, you probably should replace it. The good news is if that is the case then the o-ring won't be likely to add to the shipping cost. :giggles

[technostructural]

Alright, so here are a whole bunch of photos. I believe that what has happened here is that someone put an excessive amount of lube on the splines, and it flung out all over the clutch and bell housing. Here's a photo of the disc:





See those streaks in the centre near the splines? Well, there's more of that coming in the next few photos. Don't worry Laitch, I've got you covered for good images of the splines later on in this post. They appear to look pretty good, with some minimal wear.


Here's what the spring plate looked like before I took it out. Notice the streaks of lube/grease on this as well? It's also this same dark grey/black colour as the stuff found elsewhere:





When I took the spring plate off, what I found was very clean and dry:





Meanwhile, the bell housing surrounding the flywheel is noticeably more oily and dirty:





Notice how you can see those consistent streaks outside of the area where the spring plate would rest? This makes me think that this is excess lube from the splines rather than the rear main seal leaking.


I figured I'd go ahead and measure and inspect the clutch disc. As far as thickness goes, I appear to be OK at 5.28mm:





The disc does look a bit grimey though. What is odd is that I have never experienced any performance issues with the clutch. It seems to be caked in a combination of clutch dust and moly lube. Is this salvageable with some brake clean and sandpaper perhaps?





Another shot of the disc / pack:





The friction plates look to be tainted with a bit of this gunk too:










And lastly - the splines on the disc. They look pretty good to be honest:








So, I guess all of this begs a couple of questions:


(1) Should I clean up these clutch parts and put them back together, or is the 5.28mm close enough to minimum spec that I should replace at least the disc anyway? I am not sure what the thickness of a new clutch disc is (i.e. the "maximum thickness"), and so I don't know how worn down this really is.


(2) Since the rear main seal does not appear to be leaking, should I still replace the o ring mentioned by Gryphon? If so, can anyone provide me with some guidance on removing this large (what appears to be 26mm) nut? Nothing is going to fall off, is it? How does it get torqued back on?


Thanks for the help and guidance everyone.

[Laitch]

Your disc splines are the envy of the neighborhood. If your clutch has been working well, the seal or o-ring are not leaking, and the clutch housing can be cleaned spic and span, what is there to fix? What do you think is the wear limit of the friction disc? What is your opinion concerning new carrier bolts? Have you made the parts measurements for SJK as promised?

Two schools of thought:
Replace the clutch nut and o-ring even if they are not leaking so they'll never need service again.
Don't replace the clutch nut and o-ring because they are not leaking and nobody knows how long never is.

[The Mighty Gryphon]

I haven't looked it up in my Clymer manual tonight, but I seem to recall that a new clutch is 5.5mm and the service limit is 4.5 mm so it looks like you are barely worn on your disc. (check the  manual to confirm).

I suppose a good solvent soak and a bit of sanding could help, but you need to be very careful that the friction surface stays perfectly flat, otherwise any gain in the coefficient of friction will be offset by the loss in contact area due to unevenness.

The o-ring is a tough call.  If it has not been previously replaced, there is a good chance that it is hard and not sealing as well as a new one.  But there is no leakage at this time that demands it be changed.  How much additional work do you want to do, and how soon do you want to go in there again?

As far as removing the nut.  I used an impact wrench with a socket and it spun right off.  A torque wrench is mandatory for reinstalling. 

[alexis291]

Interesting post with some great photos.
I think your diagnosis of the oily deposits (albeit not having seen / felt / smelled them myself) is correct in that they are likely to be spline grease and clutch dust.
My view on the o-ring is that, if you leave it,  you may end up forever wondering how long it will last and wishing you'd changed it. Unless you think changing it carries risks of making a mess of the job (and you seem pretty competent), I would replace it. Then you can sleep easy!


Sent from my iPhone using Tapatalk

[Laitch]

I haven't looked it up in my Clymer manual tonight, but I seem to recall that a new clutch is 5.5mm and the service limit is 4.5 mm...

It's 4.3mm. I was wondering how techno arrives at his conclusions. Your answering instead doesn't help in that regard. I think I'll shift back to learning the panoply of Finnish descriptions for snow types.

[technostructural]

I took a look at the service manual too, and it looks like 5.3mm is roughly the thickness of a new clutch:





Given that mine is 5.28mm, I think I will consider it to have lots of life left  :clap:


The general consensus seems to be that changing the o-ring now is worth the peace of mind, even if it has some more life left in it. I am inclined to agree. I will make sure I pick up the part.


As for cleaning the disc and plates, I think I will stick with just using some solvents and a microfiber rag. While I think I would have to do quite a job on it to augment the thickness via sandpaper, I agree with Gryphon that it's not worth the risk. It's probably not worth the health hazard anyway -- aren't these things made with asbestos?

As for my conclusions? Well, they are mostly the result of reading posts in the Lieberry, watching Chris Harris' videos, reading the service manual, and of course your collective suggestions. Thanks for those by the way.

Oh, and no need to bother with Finnish descriptions for snow types Laitch. Here in Nova Scotia we just call it miserable f***ing s**t. I think that may be a lingua franca.

[Laitch]

Peace of mind is self-generated, not thing-generated. As for snow, why bother cursing what you can't change? Get out your toboggan.  :giggles

Looks like you're right well-situated.  :2thumbup:

[technostructural]

Ah, there's nothing quite like complaining about the weather though. Maybe it is more of a Maritime tradition. I spent a couple of weeks in California, and while beautiful, I worried that if I were to live there I wouldn't have the opportunity to grumble about the weather.


Oh, and in the event that someone is reading this thread in the future and is curious about the clutch nut and o-ring, I found this thread:
https://www.motobrick.com/index.php?topic=332.0


It offers a very detailed and thorough explanation of this part of the bike. The very poor quality black and white photos in the service manual only get you so far.


Cheers.

[technostructural]

As far as removing the nut.  I used an impact wrench with a socket and it spun right off.  A torque wrench is mandatory for reinstalling.

Sorry, one further question Gryphon. Should the hex nut be replaced as well? Parts fiche at Max BMW is saying so. It seems that others have re-used it. Thoughts?

[The Mighty Gryphon]

At current prices, the parts you're supposed to replace will set you back about $60.  At the rate BMW is increasing part prices they'll cost you $100+ in a couple years.  Might as well get in there with new ones and forget about them for the next 100,000 miles.

Other than generating extra revenue on clutch work, I can't personally say why they say you need to replace those parts, I suspect it may be due to the high torque on the nut and spacer.  There might be concern about metal fatigue allowing the threads to deform and relieve the torque and the pressure on the assembly.

[technostructural]

Other than generating extra revenue on clutch work, I can't personally say why they say you need to replace those parts

I'm starting to agree with this sentiment. I've added the three parts to an existing order I have with BMW Toronto (e.g., Clutch nut, O-ring and Compression Ring).


Kind of crazy that it is going to cost about $150.00 for a bunch of little rubber bits, gaskets and nuts and bolts to do a spline lube. I hope that more "alternate" parts become available as time goes on.


EDIT: The clutch o-ring is going to cost $24.38! Holy christ almighty. Is there really no alternate part for this? I will admit that I am not always the most sensible person, but I do feel like an idiot paying this kind of price for a rubber o-ring.

[The Mighty Gryphon]

Are you sure of that $24 price.  I know the exchange rate is pretty bad right now, but Max BMW shows that o-ring(p/n 11 21 1 460 467) at $2.17.  Are you adding in the cost of the nut and the spacer to get to that $24 price?

[Laitch]

Is there really no alternate part for this? I will admit that I am not always the most sensible person . . .

The alternative is to not fix what isn't broken. You can see the that taking the bike down to the point you are now is not a big deal. Ride off and collect deposit bottles and cans to pay for the parts when you really need them—not that I want to disagree with you. :giggles

[technostructural]

Are you sure of that $24 price.  I know the exchange rate is pretty bad right now, but Max BMW shows that o-ring(p/n 11 21 1 460 467) at $2.17.  Are you adding in the cost of the nut and the spacer to get to that $24 price?

That was the price for the individual o-ring. Normally I've had OK luck with the dealer. It's usually a couple dollars more than Max, but there is no shipping involved, so it kind of works out. I suppose I could order all three bits from Max. Even with the exchange rate, it can't be too bad.

I am certainly tempted to not fix what isn't broken at this rate. Given the time required for the dealer to import these bits to their location (I will only be in Toronto over Easter weekend), I have to let the dealer know by the end of the day whether I will go ahead with the order at that price.


EDIT: Max BMW has a cheaper total price for the three parts (~$21.00), but shipping to Canada is $30.00 US. In the end, it'll be more expensive than the dealer that way.  :falldown:


Urgh.

[Laitch]

I am certainly tempted to not fix what isn't broken at this rate.

Lead us not into temptation but deliver us from BMW.

[The Mighty Gryphon]

Ask them to double check the price because you see it for sale in the States for $2.17.  You might want to check a bearing place for that o-ring.  It is shown as a 19x4.  I would guess you can get it locally in Buna N or Viton for a couple bucks.  That's what I did.

[technostructural]

Ask them to double check the price because you see it for sale in the States for $2.17.  You might want to check a bearing place for that o-ring.  It is shown as a 19x4.  I would guess you can get it locally in Buna N or Viton for a couple bucks.  That's what I did.

Ah, so there is an alternate approach here. I'll see what I can find. The dealer has confirmed that the $24 price is the price they have for it. The parts guy seems to implicitly acknowledge that it is absurd.

I really don't know much about o-ring types. Buna N and Viton eh? I'll do some research.

[The Mighty Gryphon]

Here you go:

http://www.marcorubber.com/materialguide.htm