Model 31 gearbox oil change

Helpful information and requests for assitance and advice
Post Reply
mjf65
Member
Posts: 86
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
User avatar
Stuoyb
Posts: 1229
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.
User avatar
les ward
Member
Posts: 292
Joined: Mon Jan 01, 1990 12:00 am
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
Member
Posts: 289
Joined: Sat Jan 14, 2017 11:48 am
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
Member
Posts: 86
Joined: Wed Oct 03, 2018 2:07 pm
Location: United Kingdom

Re: Model 31 gearbox oil change

Post by mjf65 »

13mm O.E it is then......
mjf65
Member
Posts: 86
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 :-(
Post Reply