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Cleaning the CVT

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Lucius Vorenus

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After 6000 km on the c400gt from '23, the sound started to be heard at low speeds. When I slow down to go over a lying speed obstacle on the road,when adding throtle, an unpleasant sound was heard (as if a turkey was mooing like a cow). Authorized service stated that due to asbestos and other dirt, the slats are slipping. They cleaned everything under warranty and the sound is gone, the transmision runs smoothly. Clean your cvts before mainteinance schedule(20k km).
 
Lucius Vorenus said:
After 6000 km on the c400gt from '23, the sound started to be heard at low speeds. When I slow down to go over a lying speed obstacle on the road,when adding throtle, an unpleasant sound was heard (as if a turkey was mooing like a cow). Authorized service stated that due to asbestos and other dirt, the slats are slipping. They cleaned everything under warranty and the sound is gone, the transmision runs smoothly. Clean your cvts before mainteinance schedule(20k km).
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How do we clean a CVT?
 
I had it cleaned in the service center as part of the guarantee at my request. It is best, if you have time and patience, to do the yourself, since it is not a job that requires any knowledge and skills and must be done meticulously. Authorized service technicians cannot charge enough for this work and it takes their time, that's why they avoid it. It is necessary to remove the components of the cvt, degrease them and re-lubricate the key places. Believe it or not, this should be done every 3 to 5 k km. You tube is full of videos that explain this procedure, here is one:
 
Lucius Vorenus said:
I had it cleaned in the service center as part of the guarantee at my request. It is best, if you have time and patience, to do the yourself, since it is not a job that requires any knowledge and skills and must be done meticulously. Authorized service technicians cannot charge enough for this work and it takes their time, that's why they avoid it. It is necessary to remove the components of the cvt, degrease them and re-lubricate the key places. Believe it or not, this should be done every 3 to 5 k km. You tube is full of videos that explain this procedure, here is one:
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I had no idea. New to scoots for the most part. Thanks!
 
wspollack said:
If you do this, I'd appreciate your making your own video, or at least take a lot of pics, please.
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If I am working on that, there will be excess parts :) . In 2000 km I will work again at a local service that is not authorized by BMW, but the craftsmen are reliable and affordable, then I will take pictures of everything. Maybe even a video if they allow me.
 
Lucius Vorenus said:
If I work there will be excess parts :) . In 2000 km I will work again at a local service that is not authorized by BMW, but the craftsmen are reliable and affordable, then I will take pictures of everything. Maybe even a video if they allow me.
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Thanks for your thoughts and future plans.

My problem is that I really don't want to screw things up, and would like pics -- and tips! -- relevant to the C 400 GT, regardless of how many YT videos there are of other makes, and regardless of the fact that I have a PDF shop manual.

I'm okay with electrical additions and bodywork removal, but the minute I attempt something strictly mechanical -- and especially having to do with an engine or drive train -- I am very fearful of screwing up something. And especially since my '23 C 400 GT was given to me by BMW in exchange for my '22 C 400 GT (which developed an engine problem -- and, no, I never worked on it).

I also find it curious that the owner's manual doesn't mention cleaning the CVT at all. It does mention "Clean/check filter for CVT" every 6,000 miles and "Replace the CVT belt and roll weights with slide shoes" every 12,000 miles, but that's it. I'm not disputing your suggestion, though, which is why if I ever attempt what you suggest I'd want some step-by-step detailed instructions.
 
When you know how cvt works, it's very logical that it gets dirty quickly, it's many years of experience with CVT transmissions with various brands and manufacturers. Not to say a common thing. after all, it is in their interest that the parts wear out as soon as possible.

They do not repair or maintain parts, interest is only to sell new parts. Thus, they reduce the work force required for maintenance and speed up the sale of new parts. Your CVT components would last longer and the ride would be smooth. 12k with out greasing and cleaning high speed rotating parts..??🙃
The only thing that must be paid attention to is the force with which the screws are tightened. I think that the required force is stated in the instructions you have.

But ok, your market is more consumer, we in Europe are a little more enterprising in avoiding unnecessary expenses.

Edit.After all, in the official service, I was told that the strange noises are coming from the clutch due to dirt in the CVT. They officially noted that they fixed the problem by cleaning the CVT.
 
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Lucius Vorenus said:
When you know how cvt works, it's very logical that it gets dirty quickly, it's many years of experience with CVT transmissions with various brands and manufacturers. Not to say a common thing. after all, it is in their interest that the parts wear out as soon as possible.

They do not repair or maintain parts, interest is only to sell new parts. Thus, they reduce the work force required for maintenance and speed up the sale of new parts. Your CVT components would last longer and the ride would be smooth. 12k with out greasing and cleaning high speed rotating parts..??🙃
The only thing that must be paid attention to is the force with which the screws are tightened. I think that the required force is stated in the instructions you have.

But ok, your market is more consumer, we in Europe are a little more enterprising in avoiding unnecessary expenses.

Edit.After all, in the official service, I was told that the strange noises are coming from the clutch due to dirt in the CVT. They officially noted that they fixed the problem by cleaning the CVT.Goodf
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Good explanation. Thanks for your time, patience, and expertise.

I don't know whether it's a Europe vs. USA difference, regarding unnecessary expenses. I think there are a lot of people over here who feel the same way you do. In my case, I'm just old -- 76 -- and tired enough of getting down on the ground (I have an artificial hip*), and getting oily, etc., that I don't want to do that kind of maintenance stuff**. And I can still afford to let the shop do it. But if the bike will run smoother, I'm all for that, so I may actually give it a shot.

By the way, I still love doing electrical modifications, sort of as a hobby, to bikes. And the good news is that most of the time I can do all of that standing up. Check out my gallery, https://billanddot.com/C400GT/ , if you have a few minutes.

* (Actually, the artificial hip may be the part of me that works best these days.)

** (In a surprise maintenance move, I sat on a low-height rolling work-stool and oiled the chain on my Royal Enfield Meteor 350 for the first time last week. I put about 2,000 miles on it last year, but I hadn't oiled a chain in 60+ years, and that was on a Schwinn.)
 
Apologies if I came across as rude or rude with the comment regarding usa vs eu costs! My only intention is to pass on my experience which matches what I have seen and heard before in terms of cvt assembly fouling and cleaning. Much respect for your dedication in describing the experiences, I have read and seen it all before here. Thank you
 
Lucius Vorenus said:
Apologies if I came across as rude or rude with the comment regarding usa vs eu costs! My only intention is to pass on my experience which matches what I have seen and heard before in terms of cvt assembly fouling and cleaning. Much respect for your dedication in describing the experiences, I have read and seen it all before here. Thank you
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You were fine, and have provided useful information, too!
 
Lucius Vorenus said:
Apologies if I came across as rude or rude with the comment regarding usa vs eu costs! My only intention is to pass on my experience which matches what I have seen and heard before in terms of cvt assembly fouling and cleaning. Much respect for your dedication in describing the experiences, I have read and seen it all before here. Thank you
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I am second generation Polish (Warsaw). We are genetically programmed to do our own work and be frugal!
 
I remember my Vespas having this issue and making noise and not working as smoothly. I was able to blow the dirt and dust out with compressed air not the perfect solution but it worked pretty well until the service interval. I don't remember the exact proceedure but I remember doing it and it was pretty easy.
 
Lucius Vorenus said:
In essence, it is necessary to remove everything, variator, bolt, multivar, bell, degrease by washing, sand the plates on the clutch, grease the axles with graphite grease and put it back.
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I'm sure your method is best by a long shot. And the more often you do it the better. However on my Vespas I use to just pressure blow my VCT at about 3000 to 3500 miles and then clean it at 7000 to 8000 miles in the winter when I wasn't riding it. ( I average about 7500 miles each summer.) I learned the method from people on the Vespa forum. The first time I heard noise from the CVT I looked into it. Once I blew out the dust, sure enough the noise went away and the scoot ran smooth again for a while. I don't know if the air pressure method is even doable on the C400gt but if it is, and it is easy like it was on the Vespa, and it works. I will likely use it for interum maintenance. Those parts get dusty in a very short period of time. And it may be that when dusty they just generate more dust even more quickly. We'll see.
 
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yes, it looks like that and they cleaned it in an authorized service, with an air compressor. Among the services, it is much more practical to do it in the way you described, and in my way, every 6-7k km.. Of course, it must be cleaned
 
Lucius Vorenus said:
After 6000 km on the c400gt from '23, the sound started to be heard at low speeds. When I slow down to go over a lying speed obstacle on the road,when adding throtle, an unpleasant sound was heard (as if a turkey was mooing like a cow). Authorized service stated that due to asbestos and other dirt, the slats are slipping. They cleaned everything under warranty and the sound is gone, the transmision runs smoothly. Clean your cvts before mainteinance schedule(20k km).
Click to expand...
I have the same bike and the same issue

The only thing really needed is to clean the rear bell ( where the clutch shoes grip) get all the dust out and then importantly with some sand paper take the glaze off the clutch shoes otherwise it will sonetimes slip and make noises. I have done this about 4 times do far and have 20,000 kms on the bike. It pretty easy to do but you need and impact to get the rear nut off the clutch bell
Don't take off the clutch itself it's not needed just thebell and with the clutch still on sand paper the shies and finally contact cleaner is used
 
nbevan said:
I have the same bike and the same issue

The only thing really needed is to clean the rear bell ( where the clutch shoes grip) get all the dust out and then importantly with some sand paper take the glaze off the clutch shoes otherwise it will sonetimes slip and make noises. I have done this about 4 times do far and have 20,000 kms on the bike. It pretty easy to do but you need and impact to get the rear nut off the clutch bell
Don't take off the clutch itself it's not needed just thebell and with the clutch still on sand paper the shies and finally contact cleaner is used
Click to expand...
you are right that you don't need to remove everything every 5k km, but only the bell, which after cleaning the dust must be sanded or notches must be made, roughness on it so that the lamellas do not slip. And the lamellas must be sanded. so, the goal is to make the surface of the bell and the lamella rough so that they don't slip. Also, once every 20k km EVERYTHING should be removed, cleaned and lubricated.
 
Hi.
I would like to ask if someone could describe the torque with which the screws should be tightened after disassembly. I'd rather do it myself than take it to a service station. Somehow I don't trust service centers anymore.
 
I searched and found this information in several places. The small screws that hold the cvt housing must be tightened to 10Nm, and the screw that holds the variator and the clutch must be tightened to 100Nm.
I took off the cvt cover yesterday and blew it all out with high pressure air. It was quite dusty, it was time to clean it. The scooter has 11,800 km. I plan to change the belt and rollers at 20,000 km.
Does anyone have experience with the Malossi cvt belt, or should I buy the OEM BMW set instead?

I have 1 more question. How many cm is the marked distance on the variator? I forgot to weigh it when I took it apart yesterday. I would like to order a removal tool for it, but I don't know how big it should be.
Thanks.

Képernyőfotó 2024-07-08 - 11.02.39.webp
 
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