Triumph TR6 PI Operation Manual page 281

De-energising
When the solenoid is de-energised its valve is closed
by a spring, cutting off the oil supply from the pump to
the dashpot. Oil is now exhausted via the control orifice in
passage
'z'
which allows the relief valve spring to relax to
OVERDRIVE-J TYPE
its direct drive position. The dashpot spring moves"1lie
dashpot piston to its stop allowing the system pressure to
progressively drop which enables the clutch springs to move
the cone clutch gently into contact with the annulus.
The residual pressure of approximately 20 p.s.i. is
now maintained in direct drive.
KEY
I. Pressure filter.
2.
Cam.
3. Input shaft.
4. Operating pistons.
5. To central lubrication.
6. Solenoid valve.
7. Dashpot.
8. Passage Z.
9. Relief valve.
10. Pump.
HYDRAULIC SYSTEM
~~AINTENANCE
Hydraulic pressure is developed by a plunger type
pump, cam operated from the input shaft. The pump draws
oil from an air-cooled sumo throu!!h a suction filter and
delivers it via non-return valve, through a pressure filter to
the operating pistons, solenoid valve and relief valve.
Incorporated in the relief valve is a spring dashpot which
ensures smooth overdrive engagement and disengagement
under varying conditions.
LUBRICATION SYSTEM
Oil is discharged through the relief valve direct to an
annular channel in the centre of the main casing and then
through drillings in the mainshaft to the annulus spigot
bearing. Immediately in front of the spigot bearing a radial
drilling passes oil through the uni-directional clutch, from
here it is directed by an oil thrower into a catcher disc on
the plane t carrier and to the planet bearings via the hollow
planet bearing pins.
The. pressure in the lubrication passage is controlled
by the lubrication relief valve.
!
Triumph TR6 Manual. Part No.
54,S.:.!77
Issue I
The level of oil should be checked at the gearbox. To
drain the sump of the overdrive must be removed as well as
the gearbox drain plug. this will provide access to the
suction and pressure filters, which should. also be removed
and cleaned before replenishing with ne\\l oil.
Following complete draining and refilling, run the
transmission for a short period then re-check the oil level.
It is essential that only the approved lubricant is used
for topping up and refilling. ON NO ACCOUNT SHOULD
ANY ANTI-FRICTION ADDITIVES BE USED.
CLEANLINESS
Scrupulous cleanliness must be maintained
throughout all servicing operations. Even minute particles
of dust, dirt or lint from cleaning cloths may cause
malfunction. When the overdrive and gearbox have a
common oil supply, it is naturally as important that the
same high st;tndards of cleanliness must be maintained
when servicing the gearbox.
Great care must be taken to avoid the entry of dirt
when topping up or re-filling.
For cleaning use petrol or paraffin ONLY, and on no
account should water be used.
40.00.10]