Does a Jaguar Mk2 have a limited-slip differential?

The 3.8 Mk2 came with a Powr-Lok limited-slip differential as standard; it puts the power down cleanly out of corners and is a genuine performance feature.

Can you change the axle ratio on a Mk2?

Yes — the Salisbury axle was offered in several final-drive ratios, and owners often fit a taller ratio for more relaxed cruising, especially with a five-speed conversion.

What oil does the Mk2 differential use?

A hypoid EP gear oil to the correct specification, with a limited-slip additive where required for the Powr-Lok; confirm against the workshop manual.

Why is my Mk2 rear axle noisy?

Whining or clonking usually points to worn crown-wheel-and-pinion or bearings, or a tired limited-slip unit; a specialist rebuild restores it.

Upgrade guide

Rear Axle & Differential

By Jon Cosson — classic-car owner, North Yorkshire, near Thornton-le-Dale

Underside view of a classic British saloon on a ramp showing the live rear axle, leaf springs and differential casing — Placeholder image — owner to replace with a photograph of the car's own rear axle and differential.

The Mk2's rear axle rarely gets attention until you want to change how the car is geared — but the differential ratio has a big effect on how relaxed (or frantic) the car feels, especially alongside a five-speed conversion.

The Salisbury axle and Powr-Lok

The Mk2 uses a Salisbury live rear axle, and the 3.8 came with a Powr-Lok limited-slip differential as standard — a genuine performance feature that puts the power down cleanly out of corners rather than spinning one wheel. It is a robust unit, and a well-maintained Powr-Lok is a real asset.

Ratios and gearing

The axle was offered in a range of final-drive ratios. A lower (numerically higher) ratio gives urgent acceleration but busy cruising; a taller (numerically lower) ratio relaxes the motorway gait at the cost of some low-gear punch. Owners choose a ratio to suit how they use the car — and the choice interacts directly with a five-speed conversion, whose overdrive top already drops the revs.

Rebuilding and upgrading

A worn or noisy diff (whining, clonking) can be rebuilt; a tired Powr-Lok can be refreshed or replaced. Some owners fit a different ratio at rebuild time. Fresh hypoid EP oil (with the limited-slip additive where needed) keeps it healthy.

On our car

873 EUT runs a Salisbury limited-slip differential with a 3.54 ratio — a relaxed, long-legged gait that suits its five-speed gearbox. The full specification is in The Build: 873 EUT.

Common questions

Does a Jaguar Mk2 have a limited-slip differential?: The 3.8 Mk2 came with a Powr-Lok limited-slip differential as standard; it puts the power down cleanly out of corners and is a genuine performance feature.
Can you change the axle ratio on a Mk2?: Yes — the Salisbury axle was offered in several final-drive ratios, and owners often fit a taller ratio for more relaxed cruising, especially with a five-speed conversion.
What oil does the Mk2 differential use?: A hypoid EP gear oil to the correct specification, with a limited-slip additive where required for the Powr-Lok; confirm against the workshop manual.
Why is my Mk2 rear axle noisy?: Whining or clonking usually points to worn crown-wheel-and-pinion or bearings, or a tired limited-slip unit; a specialist rebuild restores it.