Jaguar S-Type (1963) - Production Developments

Production Developments

Several significant changes were made to the S-Type's interior and mechanicals during its six years in production.

Of the various performance enhancing mechanical changes, most were applied to both the 3.4S and 3.8S at the same time. These were:

• In June 1964 the original Dunlop RS5 cross-ply tyres were replaced with Dunlop SP41 radials, removing the former’s tendency to squeal under hard cornering and providing higher limits of adhesion with more gradual breakaway at the limit.
• In October 1964 the brakes were given a bigger servo, requiring lower pedal pressures.
• Also in October 1964, the Moss four-speed manual gearbox with no synchromesh on first gear was replaced with Jaguar’s own all-synchromesh four-speed gearbox. Revised gear ratios improved acceleration and a more compact Laycock A-type overdrive unit was fitted (when the overdrive option was specified)
• A very few of the last S-Types built had the same Marles Varamatic variable ratio power steering that was available on the 420 and 420G.

The only production development not shared by both the 3.4S and 3.8S was that the Powr-Lok limited slip differential option ceased to be available on the 3.4S when the 1967 cost saving trim revisions were introduced.

In 1966 a dashboard switch was provided for the heated rear window, which had previously remained “on” as long as the ignition was on, leading to instances of flat batteries.

Reflecting a tougher economic climate (and similar changes made to the Mark 2s in 1966), all S-Types made from late 1967 onwards had 'Ambla' (a brand of vinyl) upholstery instead of leather, and tufted carpets instead of woven. As part of the same revisions, dummy horn grilles replaced the foglamps in the front wings and the S-Type adopted the 420's new pattern wheel trim rings and hubcaps.