Torsion Bar Set – Jaguar E-Type Series III V-12 – 36.90" x 0.880" Diameter (Pair)
Performance & Fitment
Application: Jaguar E-Type Series III V-12 models exclusively (Front Longitudinal Torsion Bars).
Diameter: 0.880". A calibrated high-performance diameter that increases the front spring rate, designed to handle the heavy V-12 block while providing sports-car precision.
Length: 36.90" (Longer dimensional specification unique to the extended Series III chassis; will not fit Series I or II models).
Design: Solid, single-piece alloy construction optimized for maximum torsional strength and resistance to structural sag.
Material: Solid 4340 Heat-Treated 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 high-load conditions.
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.
⚠️ Caution: High-Tension Energy: Torsion bars store an immense amount of mechanical energy, which is amplified by the weight of the V-12 engine. Before loosening or attempting to remove the factory bars, you must use an E-Type 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.
❌ The Series III Extended Length Requirement: Always verify your chassis series before installation. The Series III V-12 uses a 36.90" long bar, which is significantly longer than the 32.312" bars found on 6-cylinder Series I and II models. Attempting to mix these up will result in a complete mismatch at the rear chassis reaction plate.
❌ The Spline Indexing System: Jaguar engineered the front and rear splines of the E-Type 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 0.880" 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 (Passenger side on LHD) and Right (Driver side on LHD) stamps. Swapping their sides will force the metal grain to untwist against its set, causing rapid ride height sag or premature bar failure.
Premium Construction
🇬🇧 Classic Jaguar V-12 Suspension Tech & Installation Notes
Upgrading the longitudinal torsion bars on a Series III V-12 requires strict attention to factory positioning and massive mechanical tension:
What’s Included
- (1) Pair of solid torsion bars
Warranty
Backed by a 1-year warranty for peace of mind.
Available on backorder