Gearbox oil nut - socket size?

[mattinhertford]

Hi all, very quick question, what size socket to undo the gearbox oil nut please?

Thanks

Matt

[dalebrignall]

i think the filler is 11/16 or 17 or 18 mm i cant remember off hand i just find a socket to fit , and i use a imperial / metric adjustiable spanner to do the gearbox sump plug . both are on a taper so dont go mad doing them back up sorry i cant be more help , hope you liked the little joke .

[amgrave]

3/8 whitworth according to the chart at the head of the mechanical forum.

[dalebrignall]

did not know there was a chart on here

[amgrave]

Chart, list whatever you want to call it is at the top of the mechanical forum headed spanner sizes Very useful it is too.

[bmcecosse]

It's the starting handle size (ie same as the wheel nuts) - and it's a bolt, not a nut if you are thinking of the filler.

[mattinhertford]

ah, same as the wheel nuts, good to know, thanks bmc, and everyone else too.

Any thanks for the 'bolt' 'nut' clarification too, good to know.

Matt

PS: Rear axle oil.....same as engine/gearbox (20w50)?
(I know steering rack is different)

[myoldjalopy]

No, rear axle should be hypoid gear oil - EP 90. Do not use engine oil.....

[bmcecosse]

Rear axle and rack are EP90/80. NOT engine oil ! Ideally the gearbox is SAE 30 - the '20' in the 20/50 is a bit low, and it doesn't get hot enough to reach the '50' grade which would be too high anyway.

[IslipMinor]

Matt,

All the threads on a Minor (apart from the MM) were originally 'Imperial' - generally UNF/UNC for mechanical parts, and BSF/BSW for body fittings. It you are going to do anything remotely 'serious', you do need to get a set of both spanner series, plus sockets too!

Just a note about BSF/BSW spanner sizes. Originally a BSW nut and bolt had a hexagon head 'one size bigger' than BSF, and also used a spanner size 'one size bigger' than BSF. It can be a bit confusing to understand the actual nut/bolt thread diameter, for example the wing fixing bolts use a 1/4" BSW / 5/16" BSF spanner, but are a 5/16" diameter thread (BSF). On a Minor I would always think in BSF sizes, as that will give the correct nut/bolt thread diameter as well.

The gearbox filler plug is a lovely combination - the plug head size is 3/8" BSW / 7/16" BSF and the thread itself is 1/2" BSPT!

[philthehill]

BSPT (British Standard Pipe Taper).

I note that some of the BSP taps I have are marked up BSPF (British Standard Pipe Fitting) which was the original calling.

[mattinhertford]

Great, thanks for you help everyone.

Matt