MG Magnette KA Instruction Manual page 74

I l l u s t r a t i o n 58.-View o f the gearbox partially dismantled, showing t h e flywheel housing.
The centre housing carries t h e reverse gear and t h e main and layshafts b u i l t u p on t o t h e rear end
cover.
It w i l l be noted that t h e spigot o n t h e end o f t h e mainshaft has a r o l l e r bearing and t h e
layshaft is also mounted o n r o l l e r bearings.
T h e t h i r d speed gear o n t h e layshaft is always i n constant mesh w i t h t h e t h i r d speed o n t h e
mainshaft.
T h e rear end o f t h e engine and f o r w a r d end o f t h e gearbox are supported i n
t h e frame by t h e tubular member which is located i n t h e bell housing by means
o f a b o l t and set screw o n either side. Examination o f t h e illustration w i l l s h o w
t h a t t h e clutch w i t h d r a w a l shaft is supported i n t h e bell housing. Bushes are located
t h e r e i n by means o f set screws, and t h e r e is an o i l hole i n either side o f t h e housing
for lubrication o f t h e w i t h d r a w a l shaft ends.
In dismantling t h e gearbox t h e r e is no necessity t o remove t h e nuts marked
A,
and it w i l l be noticed t h a t t h e rear end housing o f t h e gearbox is provided
w i t h lugs, so t h a t t h e rear end cover cap is removed by tapping o n t h e lugs instead
o f introducing a t o o l and damaging t h e facing.
Steel balls register i n slots i n t h e selector rods, and as t h e gear lever is moved
t o and f r o t h e balls r i d e o u t o f one slot and re-engage i n another, according t o t h e
position o f t h e lever. L o o k i n g at Illustration N o .
58,
t h e user can obtain an
excellent idea o f t h e gearbox layout, apart f r o m t h e gears themselves. I t consists
o f t h r e e principal parts ; t h e f r o n t end o f t h e gearbox is f o r m e d by t h e bell housing,
t h e centre o f t h e gearbox acts as casing and a s u p p o r t f o r t h e reverse shafting, and
t h e rear end o f t h e gearbox supports t h e shafts and t h e i r gears.
It
w i l l be seen t h a t t h e first and second speed gears, w h i c h are o n t h e left o f
t h e picture, are o f t h e straight t o o t h variety, whereas t h e constant mesh gears and
t h e t h i r d speed gears have t h e t e e t h c u t at an angle, o r w h a t is usually called
"
double helical."
Page Sixty-two