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Al Eckstadt
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qbeanie Offline OP
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I am having an issue removing the nut. The transmission is in gear which i thought should prevent the crank from turning when turning on the nut. Did i miss something? Also my Whitworth tools are loose on the nut so I'm using a crescent wrench. Yes the thread is left hand. Thx!

Last edited by qbeanie; 05/14/20 5:55 pm.
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If I remember correctly, the torque specs on this nut are misquoted in the Manual and are way too high (like 60 instead of 20 ft/lbs or something). It may be that the last time it was installed, the wrong value was used.

If you lock the back wheel with the bike in gear, that should keep the motor from turning but there is a lot of movement between the crank nut, through the transmission, and throughout the rear chain. It's best to lock the primary side, or at the pistons (if the top end is off).

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Thanks. Your correct that the torque value is lower as it broke free without me knowing. Gear is off!

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As mentioned this is a left-hand thread BSA part no 67-0643, apparently 9/16"-20 CEI.

I would try and find a close-fitting socket to undo it, ideally use a battery-operated impact wrench or try to lock the engine using one of the methods suggested above.


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Hi,
The nut hex size is oddball to say the least, 25/32in AF
a rough dodge is to use a 20mm single hexagon socket

John

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Originally Posted by chaterlea25
Hi,
The nut hex size is oddball to say the least, 25/32in AF
a rough dodge is to use a 20mm single hexagon socket

John

+1


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (now rebuilt)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)


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