Sports Quick Adjust Rear Spring Plate Set. Porsche 911 1986-89 (With G50 Gearbox)

Sports Quick Adjust Rear Spring Plate Set.
Upgrade your Porsche 911’s rear torsion-bar mounting with this Sports Quick-Adjust Rear Spring Plate Set. Ideal for 1987-89 G50 911 and 1989 Turbo models, this set replaces the original fixed plates with indexed, adjustable units featuring performance-grade bushings and high-strength steel plate. The adjustment mechanism allows ride-height and preload tuning without full disassembly, while the upgraded construction gives firmer, more consistent rear-end behaviour under load. Suitable for restoration, lowered or track-use applications, this direct-fit set ensures your rear suspension mounts operate at a higher standard.

Sold As A Set.

Fits:

• Porsche 911 1987-1989 3.2L G50
• Porsche 911 1978-1989 3.3L Turbo (930)

Diagram Ref No 16

What This Product Does:

• On this generation of Porsche 911 with rear torsion-bar suspension, the spring plate is the component that anchors the torsion bar end to the chassis/axle assembly. It controls ride height, torsion bar preload, and helps maintain correct rear-axle geometry (camber, toe, etc.).
• The adjustable variant adds an indexing mechanism so you can adjust ride-height or preload without full disassembly—useful when lowered, stiffened, or track-modified.
  
• “Sports” grade implies upgraded materials (e.g., higher hardness rubber, improved steel plate) to reduce unwanted flex and improve rear-end stability under load.

Symptoms & Signs Of Wear Or When To Upgrade:

• Rear ride-height is inconsistent or one side sits lower/higher than the other.
• The rear suspension feels loose, vague or “floating” in corners — especially under hard acceleration/braking.
• Uneven or excessive rear tyre wear (inner/outer shoulder) indicating geometry is shifting under load.
• The car has been modified (lowered, stiffened springs, wider tyres) and original non-adjustable plates limit setup or ride-height tuning.
• Visual inspection: the original plate is rusted, bushings are cracked/collapsed, the indexing mechanism is worn or non-existent.

Why This Upgrade Matters:

• Improves rear suspension precision: The adjustable plate ensures the torsion bar end is mounted with correct preload and ride-height, which helps maintain alignment under dynamic load, improving handling and tyre life.
• Facilitates tuning and setup: Especially for lowered or performance cars, the quick-adjust mechanism makes repeated setup/ride-height changes easier.
• Restores structural integrity: Original plates may have aged, corroded or lost their adjustability; upgrading renews this key mount.
• Maximises benefit of other upgrades: If you’ve upgraded torsion bars, springs, shocks, ensuring the spring plate is performance-spec ensures nothing in the rear mount is the weak link.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

91133300906

The product you are viewing cross references to these numbers