Saturday, July 17, 2010

Front suspension — torsion bar


1.Stub axle assembly

2.Eccentric bush

3.Large washerinut

4.Small washer/nut

5.Ball joint

6.Torsion bar grub screw

7.Pin

8.Upper suspension arm

9.Lower suspension arm

10.Shock absorber pin

11.Stabiliser rubber blocks

12.Metal clips

13.Stabiliser bar

14.Seal

15. Needle roller bearing

16. Metal bush

This is a very simple suspension, comprising two torsion bars per side, acting on sturdy torsion anus to which the hub assembly is bolted. The damper is attached to a special pressing which is a part of the axle assembly.
Later cars are fitted with an anti-roll bar. This simple device is in effect a 'U' shaped spring which is attached to the lower torsion arms. When one side of the suspension is compressed during cornering, the anti-roll bar flexes and compresses the suspension on the other side to a lesser extent, evening out the forces at work and preventing the car from leaning over too far.
To strip the assembly, firstly chock the rear wheels, slacken the wheel bearing nuts at the front, then raise the front of the car and support it on axle stands. Clamp the flexible brake hose as close to the brake end as possible to prevent fluid toss, then back off the adjusters and remove the brake drums, shoes, wheel bearings and brake backplates (drum brakes) or unbolt the calliper and tie it out of the way so that no strain is placed on the flexible hose (disc brakes).

Use a ball joint splitter to part the tie rod end from the steering arm and to split the ball joint in the lower suspension arm. Then remove the nut from the upper suspension arm ball joint and raise the arm using a jack and free the eccentric bush. It should now, provided the upper suspension arm is raised high enough (you may have to press the lower arm downwards slightly), he possible to remove the stub axle.
Check the condition of the ball joints and renew if necessary. The upper ball joint is fitted using a high pressure press, and it may he better to replace the upper arm complete if one can be sourced. At the top of the ball joint there should be a plastic plug which, if removed. gives access to a threaded hole. Fit a grease nipple into this and inject grease using a grease gun, stopping to move the ball joint around to help the grease penetrate properly. Fit a new plastic plug. When replacing the eccentric hush, ensure that the notched face points directly forwards.
During a full restoration, it would be usual to renew the damper units. To remove these, use a spanner on the flats of the damper shaft to hold this still whilst the top fixing nut is undone. The lower end simply unbolts. To test a damper, extend and compress it through its full range of movement; if stiff or weak points are found in the travel, or if there is any sign °clinid leakage. replace the unit.

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