Triumph TR6 PI Operation Manual page 279

PT3356 shows the position of the cone clutch when
overdrive is engaged.
It will be seen that it is no longer in contact with the
annulus but has moved forward so that its outer friction
lining is in contact with a brake ring forming part of the
overdrive casing. The sun wheel to which the clutch is
att~ched is therefore held stationary. The output shaft and
annulus continue to rotate at the same speed, so the planet
wheels rotate on their axes around the stationary sunwheel,
reducing the planet carrier and input shaft speed. The
uni-directional clutch permits the outer member to over run
the inner member.
OYERDRIVE-J TYPE
This condition gives a lower engine speed for a given
road speed.
Movement of the cone clutch in a forward direction is
effected by means of hydraulic pressure which
acts upon two pistons when a valve is opened, by
operating the driver controlled selector switch. This
hydraulic pressure overcomes the springs which load the
clutch member on to the annulus and causes the clutch to
engage the brake ring with sufficient load to hold the sun
wheel at rest.
Addition~'
load is imparted to the clutch in a
forward direction due to the helix angle of the gear teeth.
IN OVERDRIVE
KEY
I. From gearbox.
2. Sliding cone clutch.
3. Hydraulic pressure.
4. Annulus driven by planet gears.
5. To propshaft.
6. Planet wheels.
7. Locked cone clutch holds sunwheel.
8. Sunwheel.
Triumph T.R6 Manual. Part No. 545277 Issue I 40.00.08J