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Laydown gearbox cover

Submitted by george_phillips on Mon, 25/06/2018
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Nortons - General

There's a small crack in the outer cover of my laydown box. It's against one of the threaded holes into which the bolt screws that holds the inspection cover. The fact that it's cracked meant the bolt worked loose and is now residing somewhere in Cornwall.

This in turn meant that inspection cover was loose. This cover also holds the timing end of the mains shaft on which the clutch body is fitted. This could account for why I suddenly had trouble finding neutral. Too much play/wobble on the shaft.

My question is this. If that inspection cover holds the end of the mainshaft why is it not fitted with a bearing - like the layshaft? It seems a rather crude arrangment, the shaft simply sitting in a recess in aluminium alloy?

Am I missing something?

George

Submitted by george_phillips on Mon, 25/06/2018

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Stupid Boy!! I should have checked the parts book before I burst into print. I now realise that the timing end of the m/shaft is held in the m/shaft right hand bearing.

The recess in the inspecton cap merely houses the end of the clutch adjuster.

I'm going doolally from trying to sort the "sticking in first gear" issue.

My apols!

George

Submitted by paul_standeven on Mon, 25/06/2018

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Are you saying that having selected first gear, the box is reluctant to dis-engage it? What exactly happens, or as the case may be, doesn't? Detailed symptoms please

Paul

Submitted by ian_soady on Tue, 26/06/2018

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The fit of the cover is important. As you say, it supports the outer end of the clutch actuating worm and if the cover is loose you're going to lose some travel in the clutch mechanism, possibly contributing to your "sticking in gear" problem. Is this only at rest or can you select neutral while still rolling?

Submitted by george_phillips on Tue, 26/06/2018

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Paul - the usual "Norton" problem of not wanting to go into neutral from either second or first when stationary to the point that in a traffic jam I had to cut the engine, find neutral and re-start. Became difficult even when rolling.

Ian - yep. That's my conclusion. Anyway problem hopefully solved by fixing a nut on the inside of the cover with plastic padding and bolting through to it.

I've dismantled the gear box, checked all shims/thrust washers, reassembled it all; dismantled the clutch, cleaned all components, checked for burrs etc re-assembled with plates facing the correct way and am about to finish it all off and test ride.

Thanks for your interest.

George

Submitted by paul_standeven on Tue, 26/06/2018

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If the clutch is dragging, you will find it difficult to get neutral.

The could be caused by loss of lift due to a loose inspection cover. It could also be caused by the wrong primary drive oil (ATF is fashionable, but causes the clutch plates to become sticky), and also worn splines on the clutch basket or inner drum. Another cause is uneven lift due to mis-matched clutch springs

By setting my lifter carefully, I can use 7/8" pivot clutch lever (instead of the standard 1 1/8" pivot as standard) It makes for a light and very progressive clutch, and neutral is easily found.

Paul

Submitted by Xanna_jeannett… on Tue, 26/06/2018

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Hello I had the same problem and I find two things amiss one the cam platewas coming off its spline worn spline end so I welded it up, the other was the plunger for the cam-plate,it was worn so I welded the end up and regroundit back to its shape, and the cam plate timing was out, sort it out by rerigging the teeth on the cam plate arm into four gear now everything works as it should, four third second and neutraland first all now light as a feather, to select, yours anna j

Submitted by george_phillips on Tue, 26/06/2018

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Thanks for all that Paul. Hopefully the inspection cover problem is now solved so once it's all back together I'll know if it has worked.

I use Primary Chaincase oil so no probs there. The splines were smoothed a couple of months ago; the clutch springs are new. I've cleaned it all again and re-assembled it so should be OK.

George

Submitted by Xanna_jeannett… on Tue, 26/06/2018

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Previously paul_standeven wrote:

If the clutch is dragging, you will find it difficult to get neutral.

The could be caused by loss of lift due to a loose inspection cover. It could also be caused by the wrong primary drive oil (ATF is fashionable, but causes the clutch plates to become sticky), and also worn splines on the clutch basket or inner drum. Another cause is uneven lift due to mis-matched clutch springs

By setting my lifter carefully, I can use 7/8" pivot clutch lever (instead of the standard 1 1/8" pivot as standard) It makes for a light and very progressive clutch, and neutral is easily found.

Paul

Hello DO NOT USE ATF FLUIDS, This attacks the clutch centre rubbers and makes them go soft. PLEASE USE LUCAS Clutch Lubricants Formulatedfor Wet clutches, IE Norton Harley Davison'sBSA AJS MatchlessTriumph, YOURS Anna J

Attachments 10790_PrimaryChaincase_800x950.jpg

 


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