Model 31 gearbox oil change

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mjf65
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Joined: Wed Oct 03, 2018 2:07 pm
Location: United Kingdom

Model 31 gearbox oil change

Post by mjf65 »

I don't seem to have anything in the toolbox that I can get on the drain plug for the gearbox, Looks a bit tight on space to get in due to the centre stand. Any recommendations for where I can purchase the correct socket/spanner?

Thanks
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Stuoyb
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Joined: Tue Jul 27, 2004 1:00 am
Location: BEDFORDSHIRE UK

Re: Model 31 gearbox oil change

Post by Stuoyb »

It is a whitworth size - can't remember whether 1/4 or 5/16.
I found an old ring spanner, heated the shaft and bent it so it would sit flush on the drain plug and clear the back of the centre stand shaft.
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les ward
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Location: WILTSHIRE UK

Re: Model 31 gearbox oil change

Post by les ward »

I changed my gearbox oil about a week ago.
It's the flat bolt, not the domed one. Mine is 1/4 whit. I don't have a special spanner, but several flat ones with a slight bend at the end fit. Both ring and open. I feed the spanner in from the front of the bike and over the cross bar of the centre stand.
Purists can look away now, but 1/2 AF and 13mm are very close to 1/4 whit, which may give you a better range of spanners to try. Obviously if you feel them slipping stop before you round off the nut.
Hope this helps.
bob121
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Location: WEST MIDLANDS UK

Re: Model 31 gearbox oil change

Post by bob121 »

I fed my spanner in from the front as well. Bit of a pain, but easy enough. I need to replace the the plunger and spring sometime. Not convinced that I will be able to get enough clearance.
mjf65
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Location: United Kingdom

Re: Model 31 gearbox oil change

Post by mjf65 »

13mm O.E it is then......
mjf65
Member
Posts: 113
Joined: Wed Oct 03, 2018 2:07 pm
Location: United Kingdom

Re: Model 31 gearbox oil change

Post by mjf65 »

I bought a lovely little 1/4 BSW - 5/16 BSF combination ring spanner at yesterdays Stafford show I tried it for size on the 500 twin to see if it fitted which it did as the 500 had a 5/16 drain bolt fitted mine is 1/4 Whitworth and there isn't enough clearance to get it on properly :-(
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