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Clutch retaining nut

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Afternoon ..... can anyone tell me the socket size i need to undo the clutch retaining nut please?  3/8 is too small, and 1/2 wont even go in the hole.  Am i missing a socket from my carbootsale set??  1947 M18.  Ta.

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Whitworth sizes go up in 1/16" steps, fairly sure you need a 7/16" socket. Normally I would not consider using metric tools on Whitworth nuts but for this particular size I think that 21mm is a close match.

Cheers, Ian McD

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So this is what it looks like - photo attached. I've now tried every size imaginable .... WW, AF, metric.  All are either too big to go in the hole, or if they go in the hole don;t fit over the nut. Thanks!

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RGM lists this item as part number 04 0373...........5/8 (9/16BSF) X 20tpi.   This nut can also be used to hold the Dominator camshaft in place and probably that off an early Commando engine. The external size is also the same as the wheel nuts that fit my Dommies. A plug spanner will not work.

Most 5/8 WW sockets have thick shoulders which prevent them from getting inside the clutch centre. The only socket I have come across that fits inside and turns the nut was a ground down King Dick MoD item dated 1953.

I purchased a 5/8 W/W tube spanner and ground off the corners for the nut on my gearbox shaft. Later I found some thinwall tubing and after heating to red hot hammered it on and then around the nut flats. The problem with a tube spanner is getting it to torque up the nut to the correct setting.

For those people interested in measurements. You will need a socket/tube that is less than 30.5mm (1.20") wide to fit inside the clutch centre.

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The traditional 1/2" drive sockets are bulky, and often don't fit confined spaces on English motorbikes.  They need grinding down on the outside... ouch, not good practice. 

The 3/8" drive socket has sufficient torque capacity for most purposes, and will fit awkward spots like Dominator centre head bolts and clutch centre nuts

Paul

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A 5/8W socket would be a chunky item. At just over 32mm across diagonal corners it exceeds the 30.5mm internal diameter of the hub.

3/8" drive is a good suggestion but I am able to use 1/2" drive sockets on the clutch centres of both my '37 & '56 singles.

Might it be the depth of socket that prevents engagement, maybe bottoming out on the end of the shaft (the shaft is casting a bit of a shadow in the pic)? If that is the case then George's previous suggestion of a spark plug socket could be the answer.

Ian McD

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Thanks everyone - really very helpful. I'll see what i can find on good old ebay. 

Ian - no, the depth is fine. 

Thanks again .......... very much appreciated. 

Phil

 


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