HYDROLASTIC DISPLACER UNITS
Removal and Installation
On models with Hydrolastic suspension, a Hydrolastic displacer unit is used in place of the rubber cone spring unit mentioned above.
Jack up the rear of the car and support on stands, then remove the road wheel. Remove the retaining clip and disconnect the lower end of the suspension helper spring from the spigot on the radius arm. It may be necessary to raise the radius arm to allow the spring to be detached.
Depressurise the Hydrolastic system as detailed under the 'HYDROLASTIC SUSPENSION' heading later in this section.
Disconnect the displacer unit hose from the valve assembly on the rear member of the sub-frame
Depress the radius arm sufficiently to allow the displacer unit strut to be extracted from the displacer unit, then pull the tube-shaped strut rearwards to disengage its ball end from the seat in the radius arm. Turn the displacer unit anti-clockwise to release it from its locating plate on the sub-frame, then withdraw the displacer unit .
The ball foot is a simple push-fit in the end of the connecting strut and can be removed to fit a replacement. The nylon seat in the radius arm can also be levered out if a replacement is to be fitted.
When refitting the displacer unit, turn it clockwise to lock it in position on the locating plate lugs. Lubricate the strut ball end and the nylon cup in the radius arm with a suitable grease, such as Dextragrease Super G.P., before installing the strut. Ensure the rubber dust cover at the ball end locates correctly around the lip of the nylon cup.
When installation is completed, evacuate and repressurise the Hydrolastic system as detailed later in this section. Ensure that the strut remains correctly engaged at both the displacer unit and the radius arm.
The radius arms pivot on a bronze bush at the outer end of the pivot shaft and a needle roller bearing at the inner end.
These are one of the main points of wear at the rear suspension, and this is invariably due to lack of regular lubrication. A grease nipple is provided at the outer end of each pivot shaft and it is very important that these be greased frequently to keep the bearings adequately lubricated and prevent the ingress of dirt and water.
The bearings can be checked for wear once the wheel is jacked up clear of the ground. Grasp the wheel at the front and rear edge and rock the whole suspension assembly in and out. Wear will be indicated by movement of the arm casting in relation to the sub-frame at its outer pivot point. The bronze bush at the outer pivot point is more susceptible tb wear than the needle bearing at the inner end.