MOTOBRICK.COM
TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => Project Classic Motobricks => Topic started by: Atabeach on May 19, 2024, 09:21:17 AM
-
Ok people...we have splines! Ergo, Project can continue. On that subject, I think I'm missing a ball bearing race. There is supposed to be one after the "puck" No?
-
That is the revised clutch piston; there is no separate bearing. If the clutch was operating okay, the clutch rod is the appropriate one for this piston.
(https://www.motobrick.com/gallery/4/1601-190524122608.png)
(https://www.motobrick.com/gallery/4/1601-190524122817.png)
-
Thanks Laitch! That makes sense because the clutch measurement is 5.1. It’s new! Now about that gear indicator….Moving forward what’s a decent matching paint for the transmission case and swing arm?
-
Ok Folks, we have decided to put the old clutch BACK in. The new clutch pack did not have balance marks of any kind. Question, the factory clutch installation ring / housing that came with bike did not have markings. But since I know the orientation, I put it back the same way. The motor and pressure plate have yelllow marks. The finger spring, and outer ring do not. Also the clutch seems to have a brass balance rivet. The new ( not installed ) clutch does not. The two yellow marks available are 120 degrees apart. Why wasn’t the outer ring marked?
-
I've never seen a clutch housing with that many holes in it! (They drill those to remove metal to get it balanced.)
Usually they have fewer holes.
(https://i.ebayimg.com/images/g/tXYAAOSwtERk6P-v/s-l1600.webp)
-
I've never seen a clutch housing with that many holes in it!
You can check that off your bucket list! icon_cheers
If the clutch disc was within spec, what was the reasoning behind replacing the whole shebang, Atabeach—money laundering? Believe me; I know how it is down there, but real estate is the traditional method.
-
The bike had 40k on it and came with an entire clutch assembly. I got cold feet installing the new one because it had no marks. Now I have a brand new assembly for any future K bikes I will probably add to my collection. Anybody have a left side swing arm bolt? I stripped the Allen portion.
-
Ok Folks, we have decided to put the old clutch BACK in. The new clutch pack did not have balance marks of any kind. Question, the factory clutch installation ring / housing that came with bike did not have markings. But since I know the orientation, I put it back the same way. The motor and pressure plate have yelllow marks. The finger spring, and outer ring do not. Also the clutch seems to have a brass balance rivet. The new ( not installed ) clutch does not. The two yellow marks available are 120 degrees apart. Why wasn’t the outer ring marked?
It does make sense to put things back the way you found them but each part is individually balanced so it's not a huge deal. BMW also sells the parts individually, not as a balanced set. If it really mattered that much then they would not do that.
I once forgot to mark a clutch when disassembling and just reinstalled it. Worked fine.
Also the manual instructions are odd. It says offset by 120 degrees but not which way.
-
Thank you so much because I’m getting nervous about the orientation.
-
Also the manual instructions are odd. It says offset by 120 degrees but not which way.
That's not so odd. What matters to BMW—if not the rest of the world—is that the marks are separated from each other by the legs of the triangle they create instead of being stacked. The assembly is balanced regardless of which way it rotates or which mark is at either end of the triangle's base.
The obsessive among us might consider making one mark across the edges of the coupled assembly in one place before the assembly is removed, then reassemble the pack so the marks on their edges line up.
Failure in accurately aligning the clutch disc during assembly is what should really occupy obsession. :laughing4-giggles:
-
I did exactly that. I’m hoping it’s not THAT critical. The clutch itself should NEVER have marks? It rotates independently of the triangle…..being, the motor housing pressure plate and outer ring assembly. Am I missing something?
-
Am I missing something?
Lunch, perhaps? Listening to birdsong? You're getting there. Keep moving forward.
-
"Why wasn't the outer ring marked?"
There's a few possibilities. One possibility is that sometimes the mark is on the other side of the cover plate. Have a look for a paint mark on the other side, and it might not be visible until you remove it from the other balanced parts.
The diaphragm spring doesn't have a balance mark for the same reason you mentioned about the clutch, the balanced parts spin independently of them when the gears are changed.
-
Not marked. Either side. Puzzling. Especially since this is definitely the original BMW install. I guess it may not matter that much….by the way, it never occurred to me the spring spins independently…ergo not balanced. Another puzzling thing the clutch DEFINITELY has a brass weight.
-
Another puzzling thing the clutch DEFINITELY has a brass weight.
Photo, please.
-
The diaphragm spring spins with the clutch housing.
-
A couple of thought bubbles of how it seems to make sense to me. In the past I've replaced tyres. Removed the old one, removed the balance weights, installed the new one with the balance marks in the correct orientation, spun it up on a balancer, and it's balanced! Where do you put a balance weight if it's balanced first up? You don't! But then it looks like it's unbalanced cause there's no weights on it. Granted that's rare, but it sometimes happens.
The parts for balancing would be placed on a balancer, then a measured amount of steel would be removed, and then checked again for balance. If still out, more can be removed, but if only half a bees dick needs to be removed, re-drilling isn't required, simply a paint mark is placed on the heavy spot. But what if it's perfectly balanced when checked again, where would you place a balance mark? You wouldn't! This would happen more often than we might think because a calculated amount of steel is removed for initial balancing. It's a safe bet that BMW would put these parts aside, so if you buy a clutch pack, the balanced parts would all have a balance mark, or none would. I think it's a safe bet that your clutch pack parts are balanced and can be installed regardless of orientation. If there are balance marks, the three marks should be spaced evenly apart at 120 degrees.
Puzzling.
The cover plate may have been replaced with a balanced, unmarked one. It may have been oil soaked and cleaned by a previous owner who did a Mickey mouse job, removing the mark. Some riders aren't aware there are balance marks from the factory, especially since the repair manual says to mark the parts, and they could be black all over. Sometimes it's a thick blob and chips off with a rough handling.
True enough my description of the diaphragm spring is crappy, maybe I should have said it doesn't have to be synchronised with the balanced parts, which are not symmetrical, or something like that.
-
Two photos for Laitch, showing brass weight/rivet… please note my wife’s nail polish used for torque marks
-
Also the manual instructions are odd. It says offset by 120 degrees but not which way.
Actually it does say. For example the Clymer manual says either clockwise or counterclockwise, because it just doesn't matter.
Have you had it going, I'm wondering if there is a vibration which might be why a clutch pack was ordered.
-
The bike was running no vibrations whatsoever. Took her apart to lube and inspect clutch wear. The bike will get refresh paint, light relays and basic upgrades. I’ll post as I go. Thanks for the input.
-
Laitch, to be clear…the first phot shows the orientation when I took boot off. Did YOUR photo suggest otherwise. The cup portion of disk should go toward the front of bike..right?
-
Get ready for multiple incoming longshots here. Does the yellow mark on the clutch basket look more like a paint stain where a yellow paint blob used to be? Yes, I think it does. Looking at a small phone screen here, so not sure. Let's say the paint marks have been scrubbed off. Ok if we look at the cover plate above this spot, or 120 degrees from it, do we see a yellow stain? Yes, I think we do.
In the first photo of reply 17 at about nine o'clock (third bay below the 070 mark) I think I see a yellow stain, maybe you can confirm this, I'm not sure. Anyway this is either above the clutch basket yellow mark or 120 degrees from it. I'll hazard a guess that this is 120 degrees from both the yellow mark on the clutch basket, and also 120 degrees from the yellow mark on the pressure plate.
Bit of a long shot? Yes, but then it's a bit of a coincidence if it's 120 degrees from the clutch basket mark.
-
Did YOUR photo suggest otherwise. The cup portion of disk should go toward the front of bike..right?
My photo suggested otherwise. There is no disk. There is a piston. Here's how it works. The clutch arm bolt should contact the solid surface in the center of the piston, not the hole. The spring should sit in the recess of the piston to help stabilize it within the boot. The clutch rod enters the hole on the opposite side of the piston to stabilize it under pressure.
Either you didn't notice how it was assembled when you disassembled it or it was assembled incorrectly. If it was assembled incorrectly, it may not have worked smoothly sometimes.
I now realize that two pictures weren't worth a thousand words, and six words weren't worth anything either.
:laughing4-giggles:
Thanks for the clutch disk photo. That rivet has a certain je nais se qua. It probably has a purpose, like a nose ring; too bad it's hidden from public view. I prefer the garden-variety spoked clutch disk without mysterious, stylish accoutrements.
-
I spose since the clutch is made up from multiple parts it's not surprising that it might not always be well balanced and might need a balance weight in some cases.
-
Laitch, Thanks for the clarity on the boot. I'm certain of a couple of things here.1) The boot disassembly was EXACTLY in photo.2) The boot was replaced at some point because it its new and there is a pry knurl on the clamp. 3) The transmission was NEVER separated from motor...the clutch & splines not seeing the light of day since manufacture. The irony here is everything was working flawlessly. To coin a phrase " IF IT AINT BROKE FIX IT TILL IT IS" ...pure genius! Thanks Laitch. As a side note; the schematic parts drawing looks like the cup side goes toward motor, not toward spring.
-
As a side note; the schematic parts drawing looks like the cup side goes toward motor, not toward spring.
The new style piston and its orientation that we are discussing are not illustrated in that drawing, Atabeach. That is the old-style assembly. The items within the red rectangle have been replaced by the single piston unit.
-
Nicely documented, Laitch… the puck is actually 3 pieces!…. the untrained eye ( mine ) quickly glanced and saw the recess in photo as going TOWARD engine. So when the prior owner replaced the boot it was done with the hole toward the spring…I did that too… Thankfully I’m still waiting on stainless fasteners and will install correctly…ughhhh
-
It takes some practice to really see what you're looking at in these fiche diagrams, but the illustrated instructions in a MaxBMW-style fiche give a heads-up to many changes and can be helpful. You're likely to get the hang of it. BMW tends to update some parts and systems during a production run sometime making repair or maintenance an adventure.
:laughing4-giggles:
-
Nicely documented, Laitch… the puck is actually 3 pieces!…. t
The old-style assembly is three pieces. The new-style is a single molded piece.
-
Just saw this, that ramp looks like a lead in to a tragic/hilarious YouTube video :johnny :laughing1: 44271
-
She’s Alive! D-Day! Clutch has veeeery slight shudder taking off from dead stop. New gear indicator temperamental in 5th ( blank lcd ) bags, lights and front end next.