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Model 31 gearbox oil change
Posted: Mon Mar 18, 2019 9:56 pm
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
Re: Model 31 gearbox oil change
Posted: Tue Mar 19, 2019 10:58 am
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.
Re: Model 31 gearbox oil change
Posted: Tue Mar 19, 2019 12:49 pm
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.
Re: Model 31 gearbox oil change
Posted: Tue Mar 19, 2019 12:58 pm
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.
Re: Model 31 gearbox oil change
Posted: Thu Mar 21, 2019 6:37 pm
by mjf65
13mm O.E it is then......
Re: Model 31 gearbox oil change
Posted: Mon Apr 29, 2019 10:13 pm
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
