300 Series Chassis and Suspension Upgrades

The Volvo 300 Series chassis structure is exceptional compared to other rear-wheel-drive Volvos, particularly due to its DeDion rear axle design. Although parts availability was limited for a long time, the chassis can now be comprehensively upgraded.

Front spring lengths vary by model. If the goal is the lowest possible chassis using stock components, the following factors should be considered: Lowest stock spring: Found on GLT models. Its free length is 308 mm. Upgradeability: Improved suspension components are available from abroad, and enthusiasts often adapt parts from other models to enhance driving characteristics.

The rear features a rigid DeDion-type axle supported by leaf springs to the body (one per side). The differential is mounted directly to the body, not to the axle. Drive shafts are of floating design and articulated at both ends. On the right side there is an axle-reactive trailing arm.

Leaf springs differ in length and thickness. Thickness differences are most significant between Renault-engined (1.4/1.7) and Volvo-engined (2.0) variants: Model Leaf thickness at root Notes 1.4 / 1.7 5.5 mm Thinner leaf 2.0 (K-engine). 6.5 mm Stiffer leaf

Based on measured data, GLT model springs lower the rear of the vehicle by approximately 20 mm compared to other models.

Volvo's original 'green books' mention that springs are color-coded. In practice, however, these codes are almost always worn away or rusted off over time, so identification is most reliably done by measuring the spring thickness or length.