Part VI


Rear Axle Installation

by John Ironside

(This article was originally published in the January, 2014 issue of the Spark Coil.)

When my father bought our Model T in 1955, there were no shackles attaching the leaf springs to the spring perches on the axle. Instead, the car was equipped with aftermarket shock absorbers to make this connection. Both the front and rear shock absorbers—consisting of a heavy spring within a compression cylinder—have been disassembled, cleaned to bare metal, and refinished. I have never seen the name of a manufacturer on these devices.

The front shock absorbers have a threaded hole in the center to allow compression with a threaded rod so the hanger bolts can be inserted. The shock absorbers on the rear axle are a different configuration because they have no threaded rod hole, so installing the rear shock absorbers became a two-step process. First, the shock absorber was compressed to get the hanger bolt through the perch as shown in Photo #1. A furniture clamp was used because the C-clamp would not hold. In the second step, two C-clamps were required to position the absorber for insertion on the hanger bolt through the leaf spring hole as shown in Photo #2.

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Photo #3 shows the shock absorbers mounted on the rear axle and attached to the bottom leaf of the rear springs. During removal of the rear axle, the rear springs were also removed, disassembled, cleaned to bare metal, and refinished. Discussion on the Model T Forum suggested that a coating of graphite paint on the springs between leaves would improve performance and decrease spring noise. So I bought a can of Slip Plate graphite paint for about $8, and I coated each leaf thoroughly with the dry lubricant (grey color in Photo #3).

I took great precaution when disassembling and reassembling the leaf spring pack. When the springs are all compressed, tremendous energy is stored and it can be very dangerous if accidentally released. To reassemble the spring, the individual leafs were stacked together and I inserted a threaded rod with a washer and nut on each end through the center hole as shown in Photo #4. The nuts were tightened slowly—making sure the leafs stayed in alignment—until I reached full compression. Then I installed C-clamps on each side while the threaded rod was removed and the permanent compression bolt was installed. Then I installed spring clamps around each side of the pack to ensure that alignment would be maintained.

Photo #5 shows the rear axle with leaf spring ready for installation. Having temporarily wired the universal end of the drive shaft up into alignment with the engine, I rotated the male end of the universal to fit the socket in the transmission, and then shoved the entire assembly forward into position. Then I jacked up the rear axle to mate the spring with the frame. On the floor in Photo #5 is a U-shaped 1-1/2″ bar that is fastened to the frame with U-bolts on each leg to hold the rear springs in place. This bar was another feature on the car when purchased in 1955, and the hole at the apex suggests that this aftermarket device was used as a hitch. Also on the floor is a leather pad that was fabricated to match original design; it is fitted between the spring and frame. After bolting up the spring to the frame, I completed the job by bolting the universal joint cap to the transmission housing with cotter keys on the upper two bolts and wire-tying the two lower bolts together.

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In the concluding part of this story I will address the challenges faced while installing the parking breaks prior to mounting the wheels.