Description |
The Renault transmission assembly comprises of the clutch housing, five
speed gearbox, crown wheel and pinion and differential.
The gearbox is in two shaft all indirect five speed manual, with drive
passing in via the upper, primary shaft, and out via the lower secondary
shaft, onto the front end of which is formed an integral final drive
spiral bevel pinion. Synchromesh is fitted to all forward speeds, with
the 1st/2nd synchronizer mounted on the secondary shaft, the 3rd/4th
synchronizer on the primary shaft, and the 5th synchronizer on the
'overhung' rear end of the primary shaft.
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Reverse Gear |
Reverse gear is achieved by sliding an idler spur gear into engagement
with both a drive gear integral with the primary shaft, and the spur
gear teeth machined on the outside of the 1st/2nd synchronizer assembly.
Synchromesh on 3rd/4th and 5th gear is of the conventional Borg-Warner
type, whereas that on 1st/2nd gear is of the inverted cone type for
maximum cone surface area.A clutch shaft, which
carries the friction plate on 21 splines is supported at its front end
by a ball type spigot bearing in the crankshaft, and is connected at its
rear end by a roller bearing at the front, and a double ball bearing at
the rear, whereas the secondary shaft uses a roller bearing at the front
and a dual taper roller bearing at the rear. Needle roller bearings are
used on each of the 'free' pinions.
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Final Drive |
The final drive assembly is incorporated into the front end of the
transmission casing between the clutch housing and gearbox, and shares a
common oil supply. A spiral bevel gear crown wheel and pinion is used,
with a four pinion bevel gear differential or a Lotus Compact Torque
Biasing Differential (standard on Sport 300).
Short splined shafts, integral with the differential sun gears, project
through each side of the casing where they carry the inboard C.V. joints
of the drive shafts. The crown wheel/differential carrier assembly is
supported by taper roller bearings which are adjustable for pre-load.
Final drive pinion depth is controlled by gearset matching and is not
adjustable, but crown wheel and pinion backlash is set using shim
washers.
On cars using a mechanically driven speedometer, the
speedometer drive gear is mounted onto the differential carrier and
mates with a driven pinion located in the right hand side of the casing.
Sport 300 models using the Lotus Compact Differential, and all
cars 95MY and newer, use an electronic speedometer which receives
signals from a sensor mounted on the right hand rear hub carrier
assembly in conjunction with a toothed ring on the driveshaft. This data
is also used by the engine management system. A blanking plug is fitted
in the transmission casing in place of the speedometer driven gear.
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Gearchange Mechanism |
Four selector shafts lie along the right hand side of the gearbox, and
are operated by a cross shaft with a single actuating finger. A slotted
interlock guide prevents more than one selector shaft being moved from
the neutral position at any one time.
The cross shaft projects from the left hand side of
the gearbox rear housing, and is fitted with a swivel 'tree' device to
which the two gearchange cables are connected. These two push-pull
cables are used to transfer movement from the gearchange lever to the
swivel tree, which translates the motion into rotational and axial
movement of the cross shaft.
The second gear selector fork is operated by it's
selector shaft via a compression spring, which ensures a rapid (delayed)
action of the synchronizer mechanism regardless of gearlever movement
speed for optimum synchronizing action when engaging 2nd gear.
The gearchange lever is spring biased towards the
3rd/4th gear plane, and must be moved against light spring pressure to
the left before selecting 1st or 2nd gear, and against similar pressure
to the right to select 5th gear. The selection of reverse gear is
inhibited by a plate at the base of the gear lever, above which a stop
end pad must be raised by lifting a collar beneath the gear knob.
This allows the lever to be moved fully leftwards and
to the rear to engage the gear.
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Transmission Lubrication |
The gearbox and final drive share a common oil supply for which square
headed drain and filler/level plugs are provided. The drain plug is
located in the forward underside of the unit, and the filler/level plug
in the left hand side, just forward of the gearbox mounting bracket.
The oil level should be checked at every service interval, and the oil
changed at 'C' services (every 24,000 miles).
Drain the transmission when the oil is warm so that it flows more
readily, and whilst the impurities are held in suspension. Clean the
replace the drain plug when the old oil has drained thoroughly and
refill ONLY with specified oil up to the level plug hole (approx. 3
litres). Clean and replace level plug.
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Gearchange Mechanism Adjustment |
A two cable mechanism is used to connect the gearchange lever to the
gearbox cross-shaft. The gearchange lever assembly is arranged to
provide a pull or push equally to both cables when moved in the fore/aft
plane. When the lever is moved side to side (crossgate), the mechanism
provides a pull to one cable and a push to the other. At the gearbox end
this cable movement is converted via a 'translator' into rotational or
axial movement of the gearbox cross shaft.The
translator consists of two parts: a swivel 'tree' and a pivot pin, the
pivot pin hangs from a splined clamp which is secured to the cross shaft
extension. The swivel tree which pivots on this pin via two ball bearing
races, has two diametrically opposed arms at its lower end and a single
arm disposed at 90° to the others, at its top end.
When the two gearchange cables pull or push together,
the lower end of the translator is pulled or pushed, and a rotation
imparted to the cross shaft. When one cable pulls and the other pushes,
the translator is rotated about its vertical axis, but since the top arm
of the translator is connected by a tie rod to a fixed bracket, the
translator itself must pivot around the outer end of its top arm, thus
imparting an axial (lateral) movement to the cross shaft.
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Gearchange Cable Adjustment Procedure |
Adjustment of the gearchange cables can only be checked after
disconnecting the ball joint on the rear end of each cable from the
translator.
- Disconnect both cable ball joints from the
translator.
- With the transmission in neutral, the gearbox cross
shaft is spring loaded axially to the 3rd/4th gear plane. If
necessary, adjust the translator tie rod so that the tie rod fixing
hole in the translator upper arm is offset 4mm inboard of a fore/aft
datum line passing through the centre of the translator clamp.
- The gearchange lever is independently spring loaded
to the 3rd/4th gear plane. With the aid of an assistant, hold the gear
lever leaning backwards approximately 7.5° in this crossgate plane.
- If necessary, adjust the length of the two cables
at their rear end ball joints so that they can be connected to the
translator without preload. Note that both gearchange cables are
identical and that the right hand cable at the gearlever end is fitted
to the left hand side of the gearbox end. As a check, move the gear
lever across the gate from right to left and observe cable movement at
the rear end. The cable that moves forward is fitted to the left hand
side at the gearbox.
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Reverse Inhibitor Setting |
The gearchange lever assembly incorporates a reverse inhibitor which
necessitates a collar beneath the lever knob to be raised before the
lever may be moved fully to the left, and then rearwards, to select
reverse gear. Raising of the collar causes a stop pad to be lifted above
an inhibitor plate allowing the lever to be moved fully leftwards. The
reverse inhibitor is correctly set if the first and second gears may be
obtained without obstruction, but reverse gear cannot be selected
without first lifting the gear lever collar.
Before any adjustment to the inhibitor plate position is made, first
check that the gearchange cables are correctly adjusted. (see above).
If necessary, remove the centre console and gear lever lower gaiter for
access, and adjust the position of the inhibitor plate for marginal
clearance between it, and the gear lever pad when the lever is moved in
the 1st/2nd plane.
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