Achilles Heel

Three cheap and easy fixes that’ll transform ride and handling

How to sort your Jaguar XJ40 or X300 suspension.

The Jaguar XJ40 and X300 left the factory with sophisticated suspension that gave them an exceptionally good ride, excellent roadholding and precise steering. As with any ageing vehicle, though, wear and decay will eventually lead to deterioration of its dynamic qualities. Old Jaguars hide this unusually well, largely because they were so good to begin with.

Knocking noises are an obvious telltale that something’s in need of attention. Vague steering, wandering on rough surfaces and a tendency to ‘steer from the rear’ when changing lanes also signify that investigation is in order.

The good news it that the solution is not necessarily expensive or a specialist task. This feature focuses on the three prime offenders: the front shock absorber mounts, the anti-roll bar bushes and the rear hub carrier bearings. Between them, these three are responsible for a large proportion of XJ40 and X300 knocking noises and handling deficiencies. They often seem to be missed by MOT testers, too. They’re all relatively cheap to rectify – and you can do all three yourself on your driveway in a weekend.

Weak shock absorbers are the fourth common culprit – so it’s worth giving these a cursory ‘bounce test’. Push firmly down on each corner of the car in turn. It should rebound and then settle. Bouncing suggests that the shock absorber on that corner isn’t doing its job. Unfortunately, these are not cheap and replacing the pair at the rear is a fairly lengthy job.