Automatic Transmission. MG 75, ZT

Automatic Transmission

Automatic Transmission GEAR SELECTOR

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H2738

The automatic transmission features a five speed gearbox with three manually selectable modes (Normal (economy), Sport and Snow mode).

The selector lever is fitted with a spring loaded catch, designed to minimise the possibility of accidental selection of the ‘P’ (Park) and ‘R’ (Reverse) positions from other drive gears or the accidental selection of a gear too low for the car’s road speed. To release the catch, press and hold the trigger mounted in the handle of the selector lever (arrowed in illustration) while moving the lever.

The following gear changes will be inhibited unless the trigger is used:

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‘P’ to ‘R’

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‘D’ to ‘4’

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‘4’ to ‘3’

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‘3’ to ‘2’

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‘N’ to ‘R’

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‘R’ to ‘P’

NOTE: A light on the selector display and a number or letter on the trip recorder display, identifies the selected gear position.

Do not press the trigger when changing gear, except when necessary.

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Automatic Transmission

Selector lever positions

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‘P’ Park

In this position the transmission is locked to prevent the car from rolling away. Select ONLY when the car is stationary and with the handbrake applied.

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‘R’ Reverse

Select ONLY when the car is stationary.

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‘N’ Neutral

Use this position when the car is stationary and the engine is to idle for a short period (eg. at traffic lights).

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‘D’ Drive

Select for all normal driving; fully automatic gear changing occurs on all five forward gears, according to road speed and accelerator position.

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‘4’ (1st, 2nd, 3rd and 4th gears)

Automatic gear changing is limited to the lower four gears only; use this position for town driving and on winding country roads.

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‘3’ (1st, 2nd and 3rd gears)

Automatic gear changing is limited to the lower three gears only; use this position in congested traffic conditions.

This position also provides moderate engine braking for descending slopes.

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‘2’ (1st and 2nd gears)

Automatic gear changing is limited to first and second gears only; use when driving up steep gradients and for negotiating very narrow, twisting roads. This position also provides more pronounced engine braking for descending steep slopes.

Always leave the car with the gear selector in ’P’

(Park) position when parked.

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Automatic Transmission

Using the automatic transmission

The following information is important - particularly for drivers who are unused to driving cars with automatic transmission.

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Before starting the engine, ensure that both foot brake and handbrake are applied.

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After starting the engine, KEEP BOTH BRAKES

APPLIED before and whilst moving the selector lever to the required drive position.

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Keep the brakes applied until you are ready to move - an

‘automatic’ will tend to creep forward (or backward) without throttle application, as soon as the brakes are released.

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Never 'rev' the engine while selecting a drive gear, or while the car is stationary with a drive gear selected - an

‘automatic’ will move immediately the accelerator pedal is pressed.

Gear change speeds

With ‘D’ selected, the road speeds at which gear changes take place will vary according to the position of the accelerator: minimum acceleration will result in gear changes at low road speed, while larger throttle openings will cause the gearbox to delay gear changes until faster road speeds have been reached

(thereby increasing the rate of acceleration).

With practice, gear changes can be made to occur at a wide range of road speeds depending on accelerator position.

‘Kick-down’

To provide rapid acceleration for overtaking, push the accelerator pedal to the full extent of its travel in a single, quick movement (this is known as ‘kick-down’). Up to a certain speed, this will cause an immediate downshift into the lowest appropriate gear, followed by rapid acceleration. Once the pedal is relaxed, normal gear change speeds will resume

(dependent upon road speed and accelerator pedal position).

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Automatic Transmission

MODE SWITCH

H2756

The automatic gearbox has three driver-selectable operating modes, Normal (economy), Sport and Snow. When the starter switch is turned on, the transmission automatically selects the Normal (economy) mode.

Normal (economy) mode

Normal mode is suitable for all day to day driving and optimises fuel consumption and exhaust emissions. To return to Normal mode after selecting either of the other modes, push the switch towards the front of the car.

Sport mode

Pull the switch towards the rear of the car to select (‘S’ appears in the trip recorder display). With Sport mode selected, the gearbox is more responsive to accelerator pedal movement - downshifts occur earlier and upshifts are delayed to make optimum use of the engine's power while accelerating.

Snow mode

Press down on the centre of the switch to select (a snowflake symbol appears in the trip recorder display).

Select Snow mode when moving from rest on loose or slippery surfaces (the car will move off in second gear and subsequently upshift at lower speeds, thereby reducing the possibility of wheel spin).

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Operating tip: Select sport mode when increased engine acceleration is required, or when negotiating long inclines, but note that driving in sport mode will increase fuel consumption.

Automatic Transmission

AUTOMATICALLY SELECTED MODES

The transmission control system automatically selects different gear change modes, listed below, designed to suit a variety of driving conditions.

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Hill ascent, trailer and high altitude mode

A suitable gear change pattern is selected to counter momentum loss, caused by the more frequent gear changing which can occur when climbing hills, or when towing a trailer or caravan. This gear change pattern is also selected at high altitudes to combat low engine torque.

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Hill descent mode

Unless some form of braking is applied, vehicles will naturally increase speed while travelling down hill. On most automatic vehicles, this results in the highest gear being selected, thereby reducing engine braking to a minimum.

On Rover 75 however, the hill descent mode provides engine braking by causing the transmission to automatically change to a lower gear on steep downhill gradients, provided the following criteria occur:

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Road speed exceeds 19 mph (30 km/h).

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Foot brake is applied for at least one second.

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Accelerator pedal is fully released.

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Cruise control mode

When cruise control (if fitted) is activated, a suitable gear change pattern is selected which is less sensitive to throttle changes. This reduces the amount and frequency of gear changes, providing a smoother ride.

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NOTE: Automatically selected modes cannot be selected by the driver and will not operate if

Sport or Snow mode are selected.

NOTE: Hill descent mode is cancelled when the throttle is reapplied.

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Automatic Transmission

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Cold start mode

In very cold conditions the automatic transmission will stay in the lower gears for longer, to help the engine reach its normal operating temperature more quickly. This will help to improve overall fuel economy and driveability, and reduce emissions.

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High coolant temperature mode

In high ambient temperatures during extreme load conditions, it is possible for the engine and the gearbox to overheat. At a certain temperature, the transmission will select a gear change pattern designed to aid the cooling process, whilst enabling the gearbox to continue performing normally in high temperatures.

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Smooth change mode

Engine torque is reduced during gear changes, creating a much smoother ride.

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Automatic neutral mode (diesel models only)

To improve fuel economy and reduce emissions, the transmission automatically selects neutral from a drive gear if the vehicle is stationary and the brake is applied. The drive gear will automatically reselect when the brake is released.

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