The suspension of any Model T Ford consists of a transverse leaf spring mounted above each of the axles. It is a pretty simple arrangement, which Henry Ford called his “three point” suspension system. This was superior to the common semi – elliptical setup used on most cars of the day because it allowed a Model T’s suspension to pivot significantly on the fore / aft axis, allowing the car to have both traction and control over very uneven terrain. Roads in the days of the Model T Ford were generally bad, unpaved, muddy, and full of deep ruts.
The rear leaf springs used on the Model T evolved over the years as most parts of the car did. Here is a brief (but not comprehensive) overview of the rear spring changes over the production run.
1909 – 1912
Eight leaves (all body styles except runabout / torpedo / roadster)
Seven leaves – roadster, runabout, torpedo. End bushings either brass or bronze.
All springs were “taper leaf” design. This was a carry over from springs designed for horse drawn carriages. All but the main two leaves were ground both on a radius and to a graceful end for appearance sake.
Springs were clamped at each end with a bolt securing each the clamps. Several clamp designs were used depending on the spring manufacturer.
1913 – 1917
Springs continued in the same general design but were less carefully ground and somewhat less dainty appearing because they were not ground as much. End bushings were changed to less expensive and better wearing steel. In 1916 model year the spring oilers were deleted from the spring shackle, and a hole drilled through each main leaf and bushing to allow oil to be added (it never was by most owners).
1918 – 27
The taper leaf design was eliminated in favor of leafs that were simply cut off on the ends. A 9 leaf spring was added for sedans. Runabout springs became 6 leaf in 1920. Beginning in 1925 the new Roadster Pickup body style also used the 9 leaf spring.
In this issue of Model T Ford Fix we disassemble the rear leaf spring and rebuild it for best handling and ride quality.