Correct friction disks GL1000 K1


Information and questions on GL1000 Goldwings (1975-1979)
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TruusjeTurbo
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Correct friction disks GL1000 K1

Post by TruusjeTurbo »



Hi Wing-fellows! I'm restoring my GL1000 K1 step by step and have questions about the friction disks.
Shifting in gear never went smooth since I bought the bike about 3 years ago.

I checked and encountered a problem with the clutch cable that I could solve with some lubricant/oil. When I pulled out the friction disks and clutch plates I saw that the friction disks are all equal (type A) instead off the first one to come out to have larger ‘teeth’ compared with the others (as read).
So I’m only going to replace the outer disk (to type B), assuming the other ones are still okay (after measuring).
Following the instructions at: https://www.ngwclub.com/forum/viewtopic.php?t=6905

Questions:
1. Is this wise or better to replace them all?
2. Can it function with 8 similar plates too?
3. the disks that came out belong to a K2, the grooves on K1 disks are different, why, wich one are best?
4. Does someone have tips/tricks for cleaning (not using abrasive)

Best regards from Trudy


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Rambozo
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Re: Correct friction disks GL1000 K1

Post by Rambozo »

In addition to checking thickness, it is important to check for warping of both the friction discs and drive discs. Use a surface plate or a piece of glass and feeler gauges. Warped discs will always make the clutch feel funny and hard to shift. It's amazing what a set of flat discs will do. If the clutch has been overheated, it's virtually guaranteed that it's warped.
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Re: Correct friction disks GL1000 K1

Post by cfairweather »

I would replace all of the clutch plates and take a close look at the steel spacers for wear. These are not expensive and you may as well make the clutch like new while you are in there. The most important thing you need to do is drill extra holes on the drum. Honda drilled some holes, but you need to add some more to improve the lubrication. There are some instructions on this site or on the NGW web site on how and where to do this, but if you can't find these docs, I can help you. Also, the middle B plate is a double and the 1976 model had a serious flaw. You must get that plate out of there, if you have the faulty design, or you risk serious engine damage when the rivets give way due to excessive stress on the one plate with teeth. The way you can tell if it is the faulty design, is the bad type has teeth on only one plate. The good type has teeth on both plates. Some people recommend you leave the double plate out and replace it with regular plates. This is a bad idea and your bike will not shift as well. Ask me how I know... You need to find a double B plate from a 1978 or 79 GL1000 model. Some late 77 models had the fixed version too. Look on ebay and you might find a new one, but you should be able to find a used one but if you can't, please contact me and I might have one. Again, make sure both plates have teeth and you will be fine.




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Re: Correct friction disks GL1000 K1

Post by TruusjeTurbo »

Thanks for your advice Rambozo and Cfairweather! I checked; the thick double plate in the middle has teeth on both plates. I can't see/feel any warp on the plates. Thickness of the friction plates is okay (3.5mm). I know, replacing them all would be best, it's not a 1-2-3 job, but I think it will be the friction plates only (7+1). I'm going to check the tip about the holes and lubrication. Thank you!
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Re: Correct friction disks GL1000 K1

Post by TruusjeTurbo »

It took a while but the plates and discs are in place and a new clutch cable is connected. Does somebody know if there's a way to test if they are reassembled correctly before installing the rest (cardan, muffler, rear fork, final driven gear, wheel etc.)?
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Re: Correct friction disks GL1000 K1

Post by Rambozo »

You can probably do some basic function checks. Did everything adjust properly and somewhere in the center of the range? There are specs for disc thicknesses that I typically check when assembling a clutch.
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Re: Correct friction disks GL1000 K1

Post by TruusjeTurbo »

When squeezing the clutch lever, shifting in gear, does the axe (to put the cardan to) has to turn? It doesn't now, only in free gear.

Before disassembling the clutch again, I'm afraid there's more trouble going on...




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Re: Correct friction disks GL1000 K1

Post by Rambozo »

You should be able to turn the output shaft with the clutch pulled in, but you will need a tool as it will take more than hand grip to turn it.
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Re: Correct friction disks GL1000 K1

Post by TruusjeTurbo »

@Rambozo, Got another tip from someone at home to use a pliers with a cloth to turn the output shaft but being afraid to damage it, a friend welded a tool for me from the old broken cardan to perform the testing and that works great!


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Re: Correct friction disks GL1000 K1

Post by GL1000K1dan »

the 1976 model had a serious flaw. You must get that plate out of there, if you have the faulty design, or you risk serious engine damage when the rivets give way due to excessive stress on the one plate with teeth


Picking up on cfairweather's statement (copied above), what is the serious damage that can be caused?
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Re: Correct friction disks GL1000 K1

Post by cfairweather »

The "serious engine damage" can result from your clutch coming apart. The clutch plate material, including metal, will be floating around in your engine and the oil screen will be completely plugged if you continue to run the engine.
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Re: Correct friction disks GL1000 K1

Post by Old Fogey »

This will show you the damage it can cause. I know CF is not a fan of replacing the B plate as I did, but I have had no problems and I know many others have done so too,
https://www.wingovations.com/clutchplatebproblems
'Impossible' is just a level of difficulty! The only stupid question is the one you didn't ask first!

( Seriously, you haven't read all 115 pages of my http://www.wingovations.com website ?? :shock: )
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Re: Correct friction disks GL1000 K1

Post by cfairweather »

First let me say that Old Fogey is an expert on the GL1000 and I highly respect any advice he offers. I am glad he provided the link to show the damage you can expect if you have an early GL1000 that has not been fixed. I have tried this method of using two regular plates to replace the B plate and it does work just fine; however, I just noticed my bike did not shift quite as smooth as it did before I made the change. Something just didn't feel as smooth, but it worked fine. Since I did that one, I have switched to using a B plate with teeth on both plates. This was the fix that Honda implemented on the 1978 later models because the pressure is evenly applied to both plates. I think they actually started this fix sometime in 1977. I have never seen any loose rivets on the fixed version.
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Re: Correct friction disks GL1000 K1

Post by Old Fogey »

No, neither have I, but the engineer in me still balks at the idea of brass rivets holding spring steel tabs. It's just wrong!
The gearchange is perhaps a little harsher, but these boxes were never exactly 'knife though butter' anyway.
'Impossible' is just a level of difficulty! The only stupid question is the one you didn't ask first!

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Re: Correct friction disks GL1000 K1

Post by whiteclad57 »

Late response I know, but I felt the need to get this out there, I have a 78 with the late model B plate, it grenaded on me and also had to be replaced after discovering it through its perplexing symptoms(clutch still worked fine when cold for several weeks), I also added the additional plates rather than risk another failure seeing as how it already caused so many problems and still seems like a terrible design.
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Re: Correct friction disks GL1000 K1

Post by alain-s »

cfairweather wrote: Tue Jan 31, 2023 8:59 pm I would replace all of the clutch plates and take a close look at the steel spacers for wear. These are not expensive and you may as well make the clutch like new while you are in there. The most important thing you need to do is drill extra holes on the drum. Honda drilled some holes, but you need to add some more to improve the lubrication. There are some instructions on this site or on the NGW web site on how and where to do this, but if you can't find these docs, I can help you. Also, the middle B plate is a double and the 1976 model had a serious flaw. You must get that plate out of there, if you have the faulty design, or you risk serious engine damage when the rivets give way due to excessive stress on the one plate with teeth. The way you can tell if it is the faulty design, is the bad type has teeth on only one plate. The good type has teeth on both plates. Some people recommend you leave the double plate out and replace it with regular plates. This is a bad idea and your bike will not shift as well. Ask me how I know... You need to find a double B plate from a 1978 or 79 GL1000 model. Some late 77 models had the fixed version too. Look on ebay and you might find a new one, but you should be able to find a used one but if you can't, please contact me and I might have one. Again, make sure both plates have teeth and you will be fine.
BPlate-Bad.JPG
PlateB-Good.JPG


Sorry for the topic kick.

I was looking for more info about the extra hole in the clutch drum but I couldn't find it here on the forum. Any change you can give me a link to it cfairweather?
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Re: Correct friction disks GL1000 K1

Post by cfairweather »

I couldn't find those old posts either so here is what I recommend. First, you when you drill a hole, you need to drill another matching hole 180 degrees on the opposite side. For example, you will notice that Honda drilled 4 holes and then drilled a matching 4 hole pattern 180 degrees on the opposite side. So keep this in mind when you decide where to drill your holes. Notice the picture below that shows the original hole count in red and the suggested numbers in black where the new holes will go. Also notice that the second picture shows the black dots where I recommend drilling the new holes. I centered the single hole and spaced the double holes slightly wider than the Honda double pattern. My goal was to spread the oil better across all the plates. Also, notice the marks/dents on the walls of the teeth. These are from the clutch tabs pressing against the the teeth with a lot of force. You should polish out these marks so the clutch plates can move freely without sticking. Try using a tiny file or some fine sand paper for this task.




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Re: Correct friction disks GL1000 K1

Post by Old Fogey »

I'm confused.
What are these extra holes supposed to do?
The clutch plates are fed oil under pressure from a squirter hole in the end of the gearbox mainshaft.
It's my belief that the original holes are not to get extra oil in but to drain the excess oil out.
'Impossible' is just a level of difficulty! The only stupid question is the one you didn't ask first!

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Re: Correct friction disks GL1000 K1

Post by cfairweather »

I agree that the holes are used to get oil out of the center, but why not use the oil to help lubricate the clutch plate tabs so they are able to move easier. I believe the shifting is improved by increasing the number of holes and extra oil should also help reduce wear of the teeth.


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