MG Midget J1 1933 Instruction Manual page 47

T h e rocker shafts in addition feed the rear camshaft bearing with a
generous supply of oil, and a duct in the forward camshaft bearing impinges
a constant stream of oil o n the camshaft drive gears. Surplus oil f r o m the
valve gear finds its way back to the engine sump down a drain passage and
external pipe at the rear of the cylinder block, and by a similar drain passage
and pipe into the auxiliary drive cover at the forward end of the crankshaft,
wheae it lubricates the d y n a m o drive and inclined shaft gears, finally passing
through the crankshaft ball race o n to the oil filter in the crankcase.
A t the e n d of the first
100
miles and every subsequent
500
miles this
restrictor pin should be withdrawn by passing a piece of stiff wir,e, hooked
at its end, through th'e hole which can be w e n in the e n d of th'e pin.
T h e
restrictor a n d its housing should b e carefully cl'eaned befor'e replacemaent.
O n n o account file the pin, alter its shape o r otherwise intcerfer,e with it.
Draining the Sum,p. Owing to dilution by petrol,
a certain a m o u n t of
which always works past the pistons into th'e sump, and chemical decom-
position caused by heat, the best oil gradually loses its lubricating properties,
and must thersefor'e b e periodically drained o u t and r'enewed. This should
be donme a t least every
1,500
mil,es, and preferably every
1,000;
it is false
economy, particularly in a small high sp'eed engine 1ik.e th'e
M.G.
Midget,
to r u n with old
"
worn o u t
" oil.
T o drain the s u m p the following procedure is adopted. I n front of the
sump will b e found the main suction pipe from th'e filter unit to the p u m p .
By disconn'ecting the pipe from the filter th,e oil can b e drained o u t of the
sump, but as the filter must eventually b e removed for cleaning this may as
well b e remov'ed right away, for by so doing it will greatly speed u p the
operation. Aft,er th'e oil has all been drained the filter should b e cleaned
a n d replaced. Wh'en refixing th.e suction pipe to the threaded e n d of the
filter great care must b,e taken to see that the pipe is fitted correctly. In-
correct refitting at this point will cause a n air leak in the oil f'eed, and the
p u m p will suck air instead of oil, resulting in a seizure
if
th'e 'engine is run
for any length of time.
Clutch Thrust. Access to this is obtained b:,,
removing the cov,er p l n ~ e
o n the clutch housing, when the lubricator
w i l l
be found underneath.
A few
drops of 'engine oil should be dropped in every
500
miles.
Gearbox and Back Axle.
T h e oil lev'el in the gearbox and in the back
axl'e should b e inspected every
500
miles and replenished
if
n~ec'essary through
t h e combined inspection and filler caps, situated, in the case of th'e gearbox,
o n t h e near side, and in the case of the back axle, o n th,e rear of th'e diff'er-
ential housing.
T h e gearbox and back axle should always b e filled up when warn~-i.e.
immediately after a run-and a short stick should b,e inserted into t h e filling
orifices to make sure that congested oil clinging inside the spout does not
give a false l'evel reading.
Overfilling must b e avoided, because excess of oil in the gearbox may
work through to the clutch and cause serious slipping, while excess in the
back axle may work along to the brakes and seriously irnp:~ir their efficiency.
T h e r e is n o danger of this
if
the fillers ace correctly used, because t h e ~ r
positions o n the gearbox and axle housings determine the
"
full
"
level
automatically.
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FORTY
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