Build Sheet Bingo Illustrations

Y96 Firm Ride

The Firm Ride package is impossible to illustrate except through part numbers. First, some basics:
  • The only unique parts of Y96 are springs.
  • Sway bars, bushings, and shocks were not changed on Firebirds and Trans Ams.
  • Y96 Firm Ride ($11), when combined with V02 Heavy Duty Radiator ($53) equals V81 Trailer Package ($64).

    There are two ways to look at these springs. The way the cars were built is different from the way spare springs were specified. The build sheets list specific springs for all 4 corners. Usually, the left and right springs did not match, because of different weights on the two sides of the car. For instance, on 1977 Trans Ams, you'd have front springs coded KU, KV, and KW. It's pretty clear that the cars get heavier as you go from U to W. The rear springs were coded PF (softer), PJ (stiff), and once in a while YP (medium).

    Here are some specific spring codes for some very heavy cars:
    DescriptionRFLFRRLR
    1977 Y82 Trans Am with 400, auto, a/c, power windowsKWKVPFPF
    Same car with firm rideKWKWPJYP
    1977 Trans Am with 400, 4-speed, a/c, power windows, HD CoolingKWKWPJPJ
    Same car with firm rideUMKWPJPJ
    You can see for this that on the automatic, Y96 option changed 3 springs. In the case of our 4-speed, Y96 only changed one spring, because the rear springs were already maxed out. This is typical of 4-speeds with air conditioning. The UM spring shown is unique to the build sheet with Firm Ride, so I don't really know how it fits into the sceme of things. It would almost have to be stiffer than KW.

    In the parts manual, the spring choices were simplified. Left and Right differences are ignored, and there are fewer springs to pick from. The chart that you'd use to pick springs is below.

    Note that in front, there's no overlap between cars with regular handling (the first six springs listed) and cars with firm handling (the last 4 springs listed). The firm springs are totally different. Also note two front springs are listed for regular Trans Am, and a single choice (the heavy one) would have been used on Trans Am with firm ride.

    In the rear, there are only 3 springs, and just 2 of those can be used on Trans Am. The 400 4-speed's got lumped in with all Firm Ride cars. They're all alike. As mentioned above, this is not how the cars were built, it's simply how they planned to supply parts. The way the cars were built, Firm Ride cars had KW springs, which were also used on (really heavy) regular Trans Ams.

    If you want to see the whole process used to to calculate how heavy the car is, the whole chart is shown here. Kind of interesting that they called the 4.9L a 302. If you can't read it, there's a bigger version available by clicking.