2002-2005 Thunderbird Rear Coil Spring – New Product! If you’ve been trying to OEM rear coil spring replacements for your 2002-2005 Ford Thunderbird, you probably already know they are no longer available from Ford or Ford dealers. They have been out of production for a number of years. These springs are custom manufactured to order to Ford factory specifications, and are then load tested and calibrated. Price is for ONE rear spring. Due to compression of coil springs over time, and to ensure proper fitment, stance and vehicle height, we recommend replacing these springs in pairs of two. The front coil spring is a different part and is not interchangeable with the rear spring.