The rear suspension uses semi-elliptic leaf springs mounted longitudinally, connecting the live rear axle to the body via front mounting brackets and rear shackles. Lever-arm dampers provide the standard damping, mounted on brackets bolted to the boot floor. The semi-elliptic arrangement was introduced with the Mk2 (GAN3) in March 1964, replacing the quarter-elliptic springs used on the earlier Mk1 small-bore Midgets, the components covered in this section relate to the semi-elliptic specification used from the Mk2 onward through to the end of 1500 production.
Rear Springs
The rear leaf springs are model-specific, 1275cc and 1500 springs have different rates and lengths to suit the differing weight distribution. Fitting the wrong spring will result in incorrect ride height, altered handling balance, and potential axle location problems. The springs mount to the body at the front via a fixed bracket and spring eye bush, and at the rear via a swinging shackle with shackle bushes. The spring eye bushes and shackle bushes are the primary wear points and should be inspected at every service interval.
Spring Mounting and U-Bolts
The springs are clamped to the axle by U-bolts with saddle plates, spring pads, and locating plates between the springs and axle tubes. These components should be inspected whenever the rear suspension is disturbed, as corroded U-bolts or deteriorated spring pads can allow the axle to shift on the springs, affecting rear wheel alignment and handling. Renewing the U-bolts and pads as a set is recommended when the springs are removed for any reason.
Lever-Arm Dampers
The rear lever-arm dampers mount on brackets bolted to the boot floor, with link arms connecting the damper arm to the axle via straps and pins. The damper brackets differ between the 1275cc and 1500. The axle straps also changed during production. As with the front dampers, exchange lever-arm units must be primed before installation by working the arm through its full travel until all dead spots are eliminated.
Damper Link Arms
The link arms connect to the damper arm via a large nut and spring washer, and to the axle strap bracket via a similar arrangement. These connections should be checked for tightness periodically, as a loose link arm will cause a noticeable knocking sound over bumps and progressively wear the link arm and bracket bores.
Rear Spring Kits
Complete rear spring kits are available for both the 1275cc and 1500, containing the springs, spring eye bushes, shackle bushes, shackle plates, and all fixings. The spring fixing kit (without the springs themselves) is available separately for owners whose springs remain serviceable but whose bushes and hardware need renewal. All kits are offered with standard rubber, road polyurethane, or race polyurethane bushes.
Polyurethane Bushes
Polyurethane spring bushes offer a substantial improvement in both durability and handling precision over the standard rubber items. The road specification provides a practical balance between improved handling and acceptable ride comfort for daily use. The race specification maximises handling response but may transmit more road noise and vibration into the cabin, a worthwhile trade-off for competition use but worth considering carefully for road cars.
Bump Stops
Rubber bump stops are fitted above the axle to prevent metal-to-metal contact at full suspension compression. These deteriorate over time, particularly if exposed to oil or brake fluid contamination, and should be renewed if they are cracked, compressed, or missing. A missing or collapsed bump stop can result in damage to the floor pan and axle tube under heavy compression, particularly when carrying loads or driving over speed bumps and pothole-edged roads.
Telescopic Damper Conversion
Rear telescopic damper conversion kits are available from specialist manufacturers for both the 1275cc and 1500. These conversions replace the original lever-arm dampers with modern telescopic units that provide superior damping control, particularly over rough surfaces and during rapid changes in road surface. The conversion kits are designed for fitment without permanent modification to the car and include all necessary brackets, bushes, and fixings.
Lowering Kits and Panhard Rod
A rear lowering kit reduces the rear ride height for a more aggressive stance. This is achieved by repositioning the spring mounting point rather than by cutting or modifying the springs themselves. A Panhard rod kit provides lateral location for the rear axle, the standard Midget rear suspension relies solely on the leaf springs for lateral axle location, which allows some sideways movement under hard cornering. The Panhard rod eliminates this movement, improving rear-end stability and driver confidence.
This is a particularly worthwhile addition for cars used in competition.