Author Topic: Spacer behind clutch  (Read 224 times)

Offline chotus52

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Spacer behind clutch
« on: 24.09. 2020 12:20 »
I have a triumph 4 spring clutch (so I have been told) on my 1955 BSA Shooting Star. When I removed the clutch, there was a spacer between the gearbox sprocket & the clutch centre drive. As the centre is keyed & tapered onto the gearbox shaft,  I can’t see any reason for a spacer. I wonder if previous owners who have worked on the bike fitted it. Any ideas?
One more thing. When I fitted the inner primary case to the engine, the rear fastening point is a couple of mm from the frame. Should there be a spacer there? If I try to pull the case in with the retaining bolt, the outer cover doesn’t sit flush to the inner which I’m sure will then leak oil. I’ve put washers between to take up the gap. Not sure if this is normal or something is out of line.
Thanks in advance
55 GF s/a

Online morris

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Re: Spacer behind clutch
« Reply #1 on: 24.09. 2020 19:46 »
There shouldn’t be a spacer there. Maybe a PO fitted one because the chain wheel sat to deep and the chain was rubbing the case? Should be obvious as that would have left some traces.
Anyway, the spacer would prevent the taper to seat, so I would definitely leave it out.
Regarding the case to frame distance, loosening the engine studs/bolts may approach the case to the frame. I had the same issue once, solved it by adding some washers between case and frame, but I had to take out one of the engine plates one day, and found out afterwards that this made the case approach the frame so the washers were no longer needed...
Don’t pull the case against the frame though because that will probably warp it and may disturb the engine to primary case oil tightness.
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Offline Swarfcut

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Re: Spacer behind clutch
« Reply #2 on: 24.09. 2020 20:24 »
   These days there are readily available clutch adaptors to mate the Triumph Clutch to the A10 sliding plate oilseal scroll arrangement.  An early Triumph 4 Spring clutch adaptor is flat on the backside, so nothing to keep the oil in when used on an A10. If this is the case, and an early Triumph adaptor has been used, the spacer could be a crude attempt to keep the oil in the primary chaincase. If this was a conversion done when the proper parts cost was prohibitive, this is a possible cheapskate solution. I would expect the clutch adaptor used here to not have a scroll. Otherwise if the clutch adaptor has a scroll the spacer is not needed, and is not an official part anyway.

 The alignment of the engine unit and primary case with the frame is sometimes not quite perfect. Sometimes folks forget the circular spacer and gaskets between the crankcase and primary inner. If all is in order here, fit the primary cover and add a suitable spacing washer between the inner chaincase and the frame. There needs to no strain in the soft alloy castings. Like Morris says, loosening all the fixings can give the best compromise position before a final tighten.

 Swarfy.



Online trevinoz

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Re: Spacer behind clutch
« Reply #3 on: 24.09. 2020 22:39 »
Swarfy, you can't use a Triumph sleeve on a BSA, the tapers are different.

Online berger

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Re: Spacer behind clutch
« Reply #4 on: 24.09. 2020 22:46 »
hi trevinoz, I read it twice , he means adaptor I think, or shall I read it again *conf2*

Online trevinoz

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Re: Spacer behind clutch
« Reply #5 on: 24.09. 2020 22:51 »
Hi Berger, read again, it's the same thing, sleeve or adapter.

Online berger

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Re: Spacer behind clutch
« Reply #6 on: 24.09. 2020 23:39 »
hi trevinoz well in that case they are different tapers, I have two triumph ones ,, any one wanna buy them  *bright idea*

Offline Swarfcut

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Re: Spacer behind clutch
« Reply #7 on: 25.09. 2020 08:09 »
Trev. I got a S/A Gearbox with what I thought was an early Triumph Clutch Sleeve/Adaptor. If you say the tapers are different, then I'm thinking this sleeve can't be a Triumph Part, it must be from the BSA range, typically  BSA C15, B25,B44, part 40 3201. Then it gets confusing as 40 3201 is also listed as Triumph part 57 2713.  Taper on the shaft must be different depending on Triumph model application, but standard on BSA Singles and Twins.

 This could be the part fitted to chot's bike rather than the correct sleeve with a scroll. We need a picture of what's what.

 Swarfy.