This article will cover Ford spindles from 1928-48 passenger cars & pickups. Keep in mind, this is for Ford cars & pickups only. Trucks and other makes such as Lincoln do not apply.
Model A (1928-1931) Spindles
Model A spindles are easily identified by the bolt on steering arm. This is the only early Ford spindle that features the bolt on arms. All others are forged into the spindle. Backing plate holes are 3/8″ diameter. Kingpin diameter is 0.812″
1932-1934 Spindles
1932-34 Ford spindles are the first of the forged steering arms. The drivers side features an upper arm for the drag link. Later models do not have a drag link arm forged on. Backing plate holes are 3/8″ diameter. Kingpin diameter is 0.812″
1935 Spindles
1935 Ford spindles are a one year only. They are the first to feature no upper steering arm. This is due to 1935 being the first year of the cross-steer steering box design. Because of that, the 1935 passenger spindle will have two holes in the steering arm (one for the drag link and the other for the tie rod). The snout will measure 5-5/8″ and backing plate holes are 3/8″ diameter. Kingpin diameter is 0.812″
1936 Spindles
1936 is also a one year only design. Very similar to the 1935, the only difference in 1936 is the snout length which is 5-3/8″ long. Beware when matching up your brake drum/hubs as the 1936 wide 5 hubs are different than the 1937-39 and they cannot be interchanged.
1937-1941 Spindles
Commonly reffered to as “round back” spindles, these are a top choice for many traditional hot rodders. They feature 1/2″ holes and use the same bolt pattern for early juice (hydraulic) brake backing plates. They also accept 1937-48 hubs & drums with no modifications needed. Kingpin diameter remained the same at 0.812″ and they feature the same cross-steer setup with two holes in the passenger steering arm.
1942-1948 Spindles
Known as “Square back” spindles due to the shape. Very similar to the 1937-41 spindles, the 1942-48’s will accept the juice brake backing plates, hubs and brakes. They have the same 0.812 kingpin diameter but require longer kingpins due to the larger bushing bosses.
