Crankcase Assembly - Triumph SPEED TWIN 1945 Workshop Instruction Manual

350
C.C.
TWIN-MODEL 3T DE L U X E
D r y sump lubrication i s used on the 3T
model.
The oil from the tank i s fed through
a pipe t o t h e pressure side of the o i l pump. From there t h e oil, under pressure,
i s fed t o the t i m i n g side plain bearing, where
it
is picked u p by t h e crankshaft annular
groove and forced through drilled oilways t o t h e big end assemblies.
It
then issues
from the big ends i n t h e form of an o i l fog, which lubricates t h e internal parts of
he
engine. The pressure is regulated by means of a release valve situated i n the front
offside crankcase. The valve consists o f a piston and spring and, should the o i l
pressure become excessive, the piston i s forced back o n i t s spring, allowing surplus
oil t o pass through t h e uncovered hole i n the release valve body t o the crankcase.
It w i l l be seen that the strength of the o i l pressure release valve spring regulates
the poundage of t h e o i l pressure.
The rocker gear, push rods and tappets, are lubricated by scavenge o i l which, after
k,eing used, returns t o the crankcase by way of the push r o d tubes.
TAPPET A D J U S T M E N T (3T)
Tappet adjustment i s made on the rocker arms after removing the t w o tappet
inspection covers o n the rocker boxes. Method of adjustment i s described i n the
W o r k s h o p Manual.
C L U T C H
The clutch o n the
3T
model has three corked and four steel plates.
A l l other
details
as
W o r k s h o p Manual.
T Y RES
Dunlop recommended tyre pressure for the
3T
model:
Front 16 lbs. Rear 18 lbs.
3T DE L U X E CRANKCASE ASSEMBLY
The lower haif o f the
3T
de Luxe engine i s fundamentally similar t o the larger engine
but differs i n the construction of the crankshaft assembly and has a white metal
timing side main bearing.
When dismantling the 3T crankcase assembly the same procedure should be followed
as
for t h e larger machines. The only difference being that the crankshaft timing
pinion has
a
thread o n
i t s
end portion and may be removed by the use of the ordinary
cam wheel removal t o o l part number Z.89. Replacing the timing side main bearing
i s a skilled task, and the bearing should
refera ably
be line reamed o r broached after
fitting i n t h e crankcase. It should be noted that the fit of this bearing controls the
oil pressure at t h e big ends, and if this bearing i s slack the o i l pressure w i l l be low.