Performance & Fitment

• • Application: Jaguar models utilizing the extended front longitudinal torsion layout (e.g., E-Type Series III V-12).

  • Diameter: 0.80". A calibrated diameter that balances modern handling stability with classic luxury cruising comfort.

  • Length: 36.90" (Longer dimensional specification unique to extended-wheelbase platforms; will not fit short-wheelbase Series I or II variants).

  • Design: Solid, single-piece alloy construction engineered for maximum torsional strength and resistance to structural sag.

Premium Construction

• • Material: Heat-Treated Aircraft-Grade Alloy Steel. Forged from premium racing-grade steel designed to handle continuous structural twisting without sagging or losing its spring memory over time.

  • Manufacturing Process: Centerless Ground. The outer body of the shaft is ground to a mirror finish, maintaining absolute diameter consistency. This precision removes all microscopic surface imperfections, eliminating potential "stress risers" where fractures typically form under load.

  • Coating: Heavy-Duty Powder Coating. Seals the raw steel against road moisture, engine oil leaks, and road salt, ensuring long-term protection against corrosive pitting.

🇬🇧 Classic Jaguar Suspension Tech & Installation Notes

Upgrading the longitudinal torsion bars on an extended-wheelbase Jaguar chassis requires strict attention to factory positioning and mechanical tension:

• ⚠️ Caution: High-Tension Energy: Torsion bars store an immense amount of mechanical energy. Before loosening or attempting to remove the factory bars, you must use a dedicated torsion bar unloading tool or safely support the lower wishbone assembly to completely relieve the tension. Attempting to force a loaded bar out can cause catastrophic personal injury and permanently distort the chassis anchorage points.

• ❌ Extended Length Verification: Always verify your chassis series and exact bar length before installation. This bar measures 36.90", which is significantly longer than the 32.312" bars found on standard 6-cylinder Series I and II models. Attempting to force the wrong length bar into your chassis will prevent the rear reaction plate from seating correctly.

• ❌ The Spline Indexing System: Jaguar engineered the front and rear splines of these torsion bars with a different number of teeth (fine vernier adjustment). This allows you to fine-tune the front ride height. Rotating the bar a single notch in the lower wishbone vs. one notch in the rear chassis reaction plate changes the front trim height by minute fractions of an inch, making it easy to level the front end perfectly.

• ❌ Spline Sockets Cleanout: Over decades, the splined sockets inside the front lower wishbones and the rear reaction plate gather road grime, hardened grease, and surface rust. Before sliding the new 0.80" bars into place, thoroughly clean out these internal receivers with a wire brush and a premium penetrating solvent. Forcing a new bar into a clogged socket can easily strip the splines.

• ❌ Anti-Seize and Lubrication: Always apply a generous coat of heavy-duty, waterproof anti-seize or a moly-based grease to both splined ends before installation. Because these splines must allow for slight movement as the lower control arm moves through its suspension arc, running them dry will cause severe squeaking, internal corrosion, and eventual seizure.

• ❌ Maintain Left & Right Orientation: Torsion bars are directional. They are structurally pre-stressed in a specific direction during manufacturing or take a permanent "set" based on the rotational torque of supporting the car. Ensure you inspect the bar ends for Left and Right stamps. Swapping their sides will force the metal grain to untwist against its set, causing rapid ride height sag or premature bar failure. 

What’s Included

• (1) Pair of solid torsion bars

Warranty

Backed by a 1-year warranty for peace of mind.