Austin/MG Metro Technical data HydragasHydragas Register

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Basic information
Austin Metro Mk1Austin Metro Mk2
Metro Mk1Metro Mk2

Three or five door hatchback, front wheel drive
Launched October 1980, replaced by Rover Metro in April 1990, automatic Austin Metros continued for a short time afterwards while Rover were perfecting the later autobox for the K-series engine.
Front anti-roll bar. Early models and MG variants have front dampers. MG Turbo has a rear anti-roll bar.

Note: This page covers models with A-series OHV engine only. For models with Rover K-series OHC or Peugeot Diesel engines, click here.

Change temperature for the below data. This function is based on Austin-Rover's recommended figure of 0.6mm per 1°C.

ModelsSuspension typeConnectionsFront trim heightRear trim height
Austin/MG Metro 1980-1990 All models except VanHydragasFront seperate, rear connected side to side327mm ± 10mm at 17°C
321mm ± 10mm at 17°C
Morris Metro 1982-1985
Austin Metro 310 1985-1990
Metrovan 1985-1990
HydragasFront seperate, rear connected side to side331mm ± 10mm at 17°C
321mm ± 10mm at 17°C

Trim height is measured from the centre of the wheel straight up to the wheelarch. Tyre pressures should be correct, the vehicle should be parked on a level surface, unladen but with a full petrol tank, and spare wheel in its correct storage position. For a half full fuel tank, it is suggested that the rear ride height should be 3mm lower, and the front 1mm lower. The vehicle should not have been driven for at least two hours. Put the steering straight ahead, bounce the car a few times, allow it to settle and then roll the car forward about a metre. Then measure the trim heights. They should be within the specifications above, and One side should not be any more than 10mm different to the other side.LC8

There are two valves for the front, located on the displacers themselves on each side of the engine bay (click on the photos below to show a close up of the valves).

Metro Hydragas valve   Metro Hydragas valve

The rear valve is underneath on the left hand side of the car (exhaust side), accessible in front of the rear wheel.


Nitrogen gas pressure:
Front: 22.4 bar ± 0.45 bar (325psi ± 6.5psi)
Rear: 15.86 bar ± 0.32 bar (230psi ± 4.6psi)

Useful Part Numbers
ModelsDescriptionPart number
Austin/MG Metro- where fittedFront damperADU3076EVA
Austin/MG Metro- All models except MG TurboFront Hydragas unitNAM4763
Austin/MG Metro- All models except MG TurboRear Hydragas unitNAM2731

Tightening torques- front suspension
PartTorque figure (Nm)
Anti-roll bar bracket to subframe26
Anti-roll bar to lower arm nut65
Hub ball joint socket102
Hub ball joint nut upper or lower arm50
Hub nut- driveshaft (align to next split pin hole)271
Lower arm pivot shaft to subframe mounting nut100
Nut- damper upper fixing38
Nut- damper lower fixing48
Upper arm pivot shaft nut75
Road wheels57

Tightening torques- rear suspension
PartTorque figure (Nm)
Hub nut (align to next split pin hole)81
Radius arm pivot shaft nut72
Back-plate to radius arm bolts26
Road wheels57

Technical drawings
eBay items

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