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MOTRS

XJ6 (Series I-III)

1968-1992 / Sedan / United Kingdom

All XJ6 (Series I-III) problems All workshop issues
Common Transmission

Borg-Warner BW66 automatic (early cars)

Symptoms

Harsh shifts, slipping, delayed engagement. The gearbox overheats under sustained load.

Cause

The BW66 is an adequate but uninspired gearbox that doesn't cope well with age or abuse. Fluid degrades, bands wear, and the torque converter loses efficiency.

Fix

Regular fluid and filter changes extend life.

When it fails, consider upgrading to a GM TH400, conversion kits are available for all XJ variants.

Budget $3,000-5,000 AUD for a TH400 conversion.

Cost mentioned in fix
Budget $3,000-5,000

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// More XJ6 (Series I-III) problems

Other known issues

Minor Transmission

GM TH400 automatic (later cars), reliable
Common Transmission

Power steering system leaks

Power steering fluid on the garage floor, heavy steering, groaning from the pump.
Minor Bodywork and Rust

Sill corrosion (structural)

Outer sills bubble and perforate. Inner sills rot silently behind trim. The car's rigidity decreases, doors sag, gaps become uneven, and the body flexes over bumps.
Minor Bodywork and Rust

Floor pan corrosion

Floor pans rot from underneath or from above (water sitting under carpets). In severe cases, you can see the road through the floor.
Common Bodywork and Rust

Rear wheel arch and lower rear quarter corrosion

Rust appears at the bottom of the rear wings, around the wheel arches, and in the lower panels between the wheels and boot.
Common Bodywork and Rust

Boot floor and spare wheel well corrosion

The boot floor rusts through, the spare wheel well fills with water, and the rot spreads to surrounding panels.
View all 28 XJ6 (Series I-III) problems