Sunbeam ALPINE I SERIES: APLINE II SERIES, Workshop Manual

Page: 150 / 413

WSM.124
Section E (Gearbox
&
Overdrive)
Self Cancelling Switch. (Fig. 13A)
When the overdrive switch Is moved to the direct
drive position, battery feed Is applied to terminal
WI, de-energising the relay coll. The contacts will
open and the circuit to terminal C1 and the over­
drive solenoid broken. Overdrive will disengage
and the warning light will go out. The overdrive
switch will return to the central position.
When the gear lever Is moved out of the 3rd/4th
gear position the gearbox switch will open and the
circuit from the fuse unit broken. If overdrive had
been engaged the relay coil will become de­
energised, the contacts will open and overdrive will
be disengaged. The warning light will go out. As
the overdrive switch will have returned to the
central position, it will be necessary to re-select
overdrive, If required, after a gearchange is made
from 2nd to 3rd gear. This ensures that overdrive
Is not engaged on changing from 2nd to 3rd gear.
A resistance In the lighting switch dims the warning
light when the side lights are switched on. (Alpine
Ill only).
LUBRICATION AND MAINTENANCE
The oil In the overdrive unit is common with that In
the synchromesh gearbox and the level should be
checked at the gearbox. To drain the gearbox and
overdrive units, the gearbox and overdrive drain
plugs must be removed.
Note:-The
overdrive drain plug
Is
the
one
nearest
the
left side of the unit. The pump valve plug In
the
centre,
and the relief valve plug
on
the right are
wired together, and are not removed unless attention
to valves Is required.
It Is essential that the approved lubricant Is used
when refilling. Trouble may be experienced If
some types of extreme pressure lubricants are used
because the planets act as a centrifuge to separate
the additives from the oil.
The combined capacity of synchromesh gearbox and
overdrive units is 4 pints {4·-4 American pints,
2·3 litres). If the units have been drained and
refilled the oil 1.evel should be rechecked after the
car has been run, since a certain amount of oil wlll
be retained in the hydraulic system.
It must be emphasised that any hydraulically controlled
transmission must have clean oil at all
times,
and
great
care
must
be taken to avoid the entry of dirt whenever
any part of the case
Is
opened.
This applies to adding
6th re-issue
Page 15
oil to the transmission and to servicing the unit.
Any dirt or even lint from a wiping cloth that finds
its way into a valve may cause serious difficulty.
When the unit Is dismantled for any service work
the parts must be thoroughly cleaned and kept
covered with an oily lintless cloth until reassembled.
Similar care should be taken when handling the
hydraulic valves, etc., since scratches or nicks
might cause leakage on reassembly.
DIAGNOSIS OF FAULTS
When positioning the vehicle for the removal of
the Overdrive, care must be taken that the vehicle
is
NOT
brought to a halt by stalling in gear.
When transmitting torque In forward direct drive,
the rollers of the unit directional clutch are forced
towards the crest of the facets of the Inner member,
and If the vehicle Is brought to a halt by stalling In
gear, the rollers can lock In the drive position, there­
by preventing the removal of the Overdrive unit.
If the overdrive unit does not operate properly, It
is advisable first to check the level of oil and, If
low, to top up with fresh oil and test the unit again
before making any further Investigations.
BEFORE COMMENCING ANY DISMANTLING OPER­
ATIONS IT IS IMPERATIVE THAT THE. OVE.RDRIVE
SWITCH IS OPE.RA TE.D TE.N TO TWE.LVE. TIME.S
WITH THE. E.NGINE. STOPPE.D, IGNITION SWITCHE.D
ON AND TOP GE.AR E.NGAGE.D TO RE.LE.ASE.
ANY
HYDRAULIC PRE.SSURE. FROM THE SYSTEM.
Faulty units should be checked for defects In the
order listed below:
Overdrive does
not
engage
1. Insufficient oil In the gearbox.
2. Solenoid not operating due to fault In electrlcal
system.
3. Control mechanism out of adjustment.
4. Insufficient hydraulic pressure due to leaks or
faulty relief valve-Test pressure.
5. Leaking operating valve due to foreign matter
on ball seat or broken valve spring.
6. Leaking pump non-return valve due to foreign
matter on ball seat or broken valve spring.
7. Pump not working due to choked filter.
8. Damaged gears, bearings or shifting parts
within the unit requiring removal and Inspec­
tion of the assembly.