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Jubilee why do I an extra clutch plate

Submitted by john_dunn1 on Mon, 29/08/2016
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Light Twins

Decided to clean clutch plates. Found that I had a extra clutch plate. All the manual drawings show seven plates I have eight.

Coming out of the clutch housing I have one plane plate which is a bit thicker than the over plates and has a slight recess around the outer edge, then a bonded plate both sides and then all other plates in the right order. This is a early Jubilee, I believe its from the first batch.

Thanks

John.

Submitted by john_dunn1 on Mon, 29/08/2016

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Re extra clutch plate.

Sorry age playing tricks. Not from the first batch. This engine is from a later date 59/60? Engine number 91867.

Norton parts shop do show a shouldered plate (recess around the outer edge) for sale but this is for a 1964 Jubilee or later, why would it be in a earlier Jubilee.

Regards

John

Submitted by terry_grimwood on Sat, 05/11/2016

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Previously john_dunn1 wrote:

Re extra clutch plate.

Sorry age playing tricks. Not from the first batch. This engine is from a later date 59/60? Engine number 91867.

Norton parts shop do show a shouldered plate (recess around the outer edge) for sale but this is for a 1964 Jubilee or later, why would it be in a earlier Jubilee.

Regards

John

Hi John, according to our guru Andy Sochanik the drawings in the manual are inaccurate. There should be 8 plates: the outermost is a half-bonded plate with the bonded side facing in, then 3 plain steel and three double-sided bonded plates alternating, and finally the innermost plate is the thicker steel plate, with the stepped side inwards ie facing the gearbox. Mine, too, had been assembled with the thicker plate on the outside, ie. Immediately after the pressure plate so this would appear to be a common mistake, not helped by the manual!

Terry

Submitted by patrick_mullen on Sat, 05/11/2016

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Hello John,

Just spotted your posting. I have a Jubilee with an engine number within 100 of yours and it's registration date (per the V5C) is Feb 1961. So I expect your machine is actually a 1961 model. This difference in years largely explains your confusion about the clutch illustrations.

The original 1959 clutch which is illustrated in the 1959 Maintenance Manual & Instruction Book for Norton Jubilee 250 is actually correct for 1959 but the same illustration has been carried forward into later editions even though there were significant changes made to the actual clutch. I have a later edition of the Maintenance Manual (which includes the Navigator 1961-63) and this is still showing an illustration of the 1959 clutch.

There are loads of other minor differences over the years as well.

Patrick

Submitted by john_dunn1 on Sun, 18/06/2017

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Previously patrick_mullen wrote:

Hello John,

Just spotted your posting. I have a Jubilee with an engine number within 100 of yours and it's registration date (per the V5C) is Feb 1961. So I expect your machine is actually a 1961 model. This difference in years largely explains your confusion about the clutch illustrations.

The original 1959 clutch which is illustrated in the 1959 Maintenance Manual & Instruction Book for Norton Jubilee 250 is actually correct for 1959 but the same illustration has been carried forward into later editions even though there were significant changes made to the actual clutch. I have a later edition of the Maintenance Manual (which includes the Navigator 1961-63) and this is still showing an illustration of the 1959 clutch.

There are loads of other minor differences over the years as well.

Patrick

Just rebuilt the gearbox and various other jobs. Put the clutch together with eight plates. I now find that the lever is very heavy to pull in. Why did they change from seven to eight plates.

Matter of interest.

My original engine which seized up soild was number 81421, as was the frame. According to Andy Sochanik this was the 6th production frame made, (March 1959) which I believe is the oldest surviving production frame, (perhaps someone knows otherwise) I purchased a complete 1960 bike with a damaged frame and put this engine into the original frame. The original engine which was seized was no good so I shoved it through the hole in my parents cellar wall below the lounge, seemed a good idea at the time, very young then. The hole was eventually bricked up. After my parents died the house was sold. Might one day knock on the door and ask for it back.

Submitted by patrick_mullen on Mon, 19/06/2017

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That is an early frame. Andy has access to the Norton production records so he knows better than most people; I would think it's probably from the first day of production.

I have bike 8144* but it has a later 1960 engine. I think this is probably from the first production batch as well. It's mostly all there and the engine runs although not quite usable; I doubt if many original engines have survived as the crankshafts apparently gave big trouble; i.e they broke.

 


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