rolie
Weekend rider
Posts: 67
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Post by rolie on Oct 27, 2021 18:07:35 GMT 1
There was too much play in the clutch basket of my 4L1 so it had to come apart. Unfortunately when it did I found the orange plastic gasket deformed and broken in two places. (Hopefully the photo on Flickr will link). The question is what to do now as I understand from previous threads that these are not available as replacement parts. I assume my options are: 1. leave it out 2. cut the outer ring off and just use the inner ring 3. put it back in its current state 4. repair it (somehow) and put it back I'd be grateful for your advice and any other options that might be available. Many thanks Rolie
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Post by stusco on Oct 27, 2021 18:37:01 GMT 1
I think its to keep the oil away from the rubbers so maybe you can make one or reuse that one as its only broken in between sections so should still stop the oil i reused mine
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rolie
Weekend rider
Posts: 67
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Post by rolie on Oct 27, 2021 22:53:52 GMT 1
Thanks
The inner and outer rings of the gasket line up with the machined surfaces on the cog which meet the basket. Even with new rubbers there is some rotational movement between the two so I think the gasket is there to protect the metal faces. In mine, there was so much play that the gasket became stretched, deformed and eventually it worked its way out past the O ring and the material broke.
I’m reluctant to reuse the existing one even though, with new rubbers, it won’t have to work as hard. It’s so badly deformed it won’t actually fit behind the cog.
It would be easy to make a new one if I knew what it was made of. It doesn’t have to do much but it obviously has to be strong and not deform over the temperature range it’s exposed to. I know that previously someone on the forum had considered making some of them. I wonder if they identified a suitable material. Does anyone know who it was?
Rolie
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Post by JonW on Oct 28, 2021 1:49:49 GMT 1
A job for Rob? Worth dropping him a PM?
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Post by dusty350 on Oct 28, 2021 7:01:06 GMT 1
Pretty sure that gasket is there to protect against the 2 metal surfaces rubbing together - the oil has free ingress around the damping rubbers. I agree that the gaskets deform and tear as the dampers wear over time, allowing more movement between the basket and the gear. The gasket is more plasticy in construction - certainly not paper based, and is pretty tough considering the life they lead. I did draw around a good one so I had a copy, should anyone decide to replicate them. They are not available separately - the basket assembly comes complete from Yamaha - so a bit of detective work will be needed to ascertain what the gasket material actually is. Dusty
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Post by midlifecrisisrd on Oct 28, 2021 8:45:24 GMT 1
It's got to be something like Teflon
Steve
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Post by bare on Oct 30, 2021 16:25:54 GMT 1
Try DIY cutting one from a piece of 'Gortex' Often used as premium automotive gaskets. An old discardable jacket possibly?
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Post by 4l04ever on Oct 30, 2021 23:18:29 GMT 1
I did have a quick look at one in the past. Looked a very similar material to the red Mica / fibre washers...
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Post by 4l04ever on Oct 30, 2021 23:24:10 GMT 1
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rolie
Weekend rider
Posts: 67
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Post by rolie on Oct 31, 2021 0:32:13 GMT 1
Bare thanks.
Interesting thought but I think it needs to be stiffer than Gortex jacket fabric.
I’ve produced a cad drawing for a CNC cutter but to be honest a DIY cut would work perfectly well as you suggest as it’s not a high tolerance item. The only thing is getting the right material.
It’s a 0.5mm thick shim that prevents contact between two metal surfaces and allows minor rotation between them. It can’t be an unique requirement so I’ve sent a request to gasket company in the hope they will suggest an appropriate material. It’s not rocket science. It’s a stiff plastic with a fairly high tensile strength, good surface wear resistance and reasonable thermal stability. I’m sure that they can supply something that will work. Here’s hoping.
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rolie
Weekend rider
Posts: 67
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Post by rolie on Oct 31, 2021 0:45:48 GMT 1
Many thanks.
The RS Mica sounds well worth a look. I’ll send for a pack.
I can always use it for beer mats if it’s no good 🙂
Rolie
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rolie
Weekend rider
Posts: 67
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Post by rolie on Nov 4, 2021 18:54:57 GMT 1
The story continues... Feedback from a very very helpful gasket manufacturer suggested 0.5mm Mylar as a suitable material confirming that it is used in industrial gearboxes and mining machinery applications. They confirmed that they could produce the gasket from my .DWG file and the cost was not unreasonable but understandably its relatively high for just one. If more people wanted them it would be cost effective.The shim is not a high tolerance item so I thought i'd try cutting it by hand. The material arrived today and I'm sure it will do the job. I cut out the shim, not perfect but good enough. Even at 0.5mm it takes some cutting with a sharp modelling knife! All I need now is a press for the rivets to complete the reassembly of the basket. Onwards and upwards! Rolie
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Post by JonW on Nov 5, 2021 1:27:06 GMT 1
Super work Rolie!
What would the costs be for these if you had say 100 done? Im sure between us you could pre sell more than half of those. Id take more than one for example... and I am not alone...
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rolie
Weekend rider
Posts: 67
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Post by rolie on Nov 5, 2021 10:37:00 GMT 1
Jon
Many thanks.
I thought there might be a demand for a few of these as I’m sure some are in a similar state to mine. It would be interesting to see how many people would want one if the unit cost was less than £20.
I’ll get a quote for 25, 50 and 100.
Rolie
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rolie
Weekend rider
Posts: 67
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Post by rolie on Nov 5, 2021 14:11:32 GMT 1
The cost supplied to me will be between £2 and £3 each depending on the quantity ordered, so it’s minimal.
I trust the recommendation of Mylar A by the supplier is appropriate, For my part I’m content that it is given the stated industrial applications and their undoubted experience. It’s certainly very tough. They have also supplied the data test sheets for Mylar A which look fine, but I’m not a materials engineer!
In the end it doesn’t have to do much as there should be minimal rotation between the basket and the gear in a refurbished unit anyway.
I’m happy to order some (say 50) but it would be good to know how much interest there was from the community.
Maybe this is even one for Norbo to put on his shelves.
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Post by JonW on Nov 7, 2021 1:19:36 GMT 1
Rolie, that sounds great mate. I will PM you.
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Post by midlifecrisisrd on Nov 7, 2021 11:16:00 GMT 1
Sounds like a bargain
I'd take a couple just in case
Steve
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rolie
Weekend rider
Posts: 67
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Post by rolie on Nov 7, 2021 11:30:40 GMT 1
Steve
No problem. That’s requests for 20 so far.
I’ll give it a few days to see if there are any more takers before I decide how many to order. The more the merrier.
The quote states 2-3 weeks from order to dispatch.
I’ll PM you when I receive them.
Rolie
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Post by oldelsieboy on Nov 7, 2021 13:37:16 GMT 1
Rolie, pm sent
OEB
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Post by 4l04ever on Nov 8, 2021 9:48:20 GMT 1
I can laser cut Mylar A if you want to try a few out before committing to loads.
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rolie
Weekend rider
Posts: 67
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Post by rolie on Nov 8, 2021 12:40:52 GMT 1
4l04ever
Thanks
There’s obviously a pent up demand for these and that will bring the unit cost way down. From my perspective the issue has never really been about getting them cut, it’s been about the identification of an appropriate material. I’ll pm you.
Rolie
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ajh
Thrash Merchant
Posts: 415
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Post by ajh on Nov 8, 2021 13:57:58 GMT 1
The cost supplied to me will be between £2 and £3 each depending on the quantity ordered, so it’s minimal. I trust the recommendation of Mylar A by the supplier is appropriate, For my part I’m content that it is given the stated industrial applications and their undoubted experience. It’s certainly very tough. They have also supplied the data test sheets for Mylar A which look fine, but I’m not a materials engineer! In the end it doesn’t have to do much as there should be minimal rotation between the basket and the gear in a refurbished unit anyway. I’m happy to order some (say 50) but it would be good to know how much interest there was from the community. Maybe this is even one for Norbo to put on his shelves. Hi Rollie I'll have one for insurance! I found some small orange pieces in my crankcase last time I had the case off Cheers
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Post by 4l04ever on Nov 8, 2021 15:37:49 GMT 1
There may be a step in height from the posts sticking out the back of the basket to the flat back surface of the gear, and the gasket maybe to take up the gap. Anyone got one apart that can accurately measure the step, which will equate to the thickness of the material required? Worth checking as the gasket material may have been compressed over time or swollen with oil ingress.
Looking at it, it should not need to move, so normal gasket paper material may work fine. The external O-ring fitted to some baskets may be a second way of keeping the oil away from the rubbers, so may need to make sure we fit one of those on too.
Kawasaki Turbos had issues with the clutch rubbers perishing after 10+ years, so maybe worth keeping oil off them.
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rolie
Weekend rider
Posts: 67
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Post by rolie on Nov 8, 2021 18:55:42 GMT 1
I’m away from the bench for a few days but when I get back I’ll bolt it together without the shim and get the feeler gauges out to check the gap and confirm that 0.5mm is the right thickness.
The cush rubbers, even when new, are there to allow some rotation so the shim needs to be able to handle this without deformation. In my opinion it needs to be more robust than gasket paper. I’ve contacted another gasket manufacturer and they have confirmed that Mylar is suitable for the proposed use which is comforting.
As far as its role in keeping oil away from the rubbers, I’m not sure why this would be necessary. In any case whatever role it and the o-ring play there is still a passage for oil under the ungasketed retaining plate that holds the gear to the basket. As this plate is directly riveted to the basket any rotational movement will be between the plate and the gear. It sits on the posts and, when riveted, is compressed against the main rubbers and the small spherical rubber inserts. This is evident from the marks on the back of the plate. Oil must surely be able to penetrate this gap.
I’m no engineer so I’d be grateful for any comments from better qualified members in case I’m missing something important.
Rolie
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rolie
Weekend rider
Posts: 67
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Post by rolie on Nov 11, 2021 23:31:14 GMT 1
Without the shim the outer edges of the gear and the basket meet, there is no gap. With the 0.5mm shim in place the top of the rivet posts are level with the flat face of the gear which, on reflection, I realise was the very sensible point that 4l04ever was making. The retaining plate will therefore compress the 4 small circular rubber inserts when the rivets are fitted, and any minor rotation between the gear and the plate will be on these. I'm therefore happy that the 0.5mm thick Mylar A shim is an appropriate replacement and I will place the order tomorrow for all those that have asked for some. They'll come in your Christmas stocking! Rolie
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rolie
Weekend rider
Posts: 67
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Post by rolie on Jan 31, 2022 18:16:22 GMT 1
Who said restoring old bikes was easy? A long time ago I started this thread and I can now move on! The shims have been delivered to me and posted to those who asked for some. They are now on three continents. I have rebuilt my clutch basket with a new shim, rubbers and rivets. I can now peen rivets! The things you learn to do doing this Thanks for all the advice. I'll be back for some more soon! Rolie
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Post by dusty350 on Jan 31, 2022 20:22:55 GMT 1
Great job ! And awesome that you took the time to sort the gaskets. Another win for Rd/Lc/Pv owners Dusty
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Post by JonW on Jan 31, 2022 23:05:23 GMT 1
Yes agreed Dusty. Rolie, thanks mate for sorting these gaskets its very much appreciated!
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Post by charles13 on Feb 1, 2022 1:24:41 GMT 1
Thanks Rolie, great little thread and the gaskets are appreciated
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rolie
Weekend rider
Posts: 67
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Post by rolie on Feb 1, 2022 15:26:20 GMT 1
Many thanks for the kind words. Glad to help out.
In the immortal words of Vinnie Jones - it’s been emotional. 🙃
Rolie
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