Bob's Resource Website (2007)

(Upper and lower outer Trunnion Install)

Oct 2000

Kent - Moore tool, J-2044,

Kent - Moore tool J-2043. They are tools that Studebaker used to spread the outer ends of the upper and lower control arm, prior to installing new trunnions.

The reason for using the tool is twofold. It creates an artificial fixed point, where the cap screws onto the trunnion pin AND holds the control arm ears apart to prevent collapse when tightening the caps.


A lower, outer pin kit

   The outside of the hardened steel cap has large, blunted, threads which score into soft steel of the control arm ears. Note: The inner loop of NOS control arms are smooth and not marked until a trunnion cap is screwed onto the pin
Control arms can be reused, once or twice, however, every time a new cap is screwed into the ear, the threads are galled into the metal, by force. There will become a time, where there isn't sufficient grip left to support holding the required torque.

When you torque the caps onto the assembly, what is taking place, is that you are, initially screwing the caps onto the pins. In the process, the outer threads on the cap are dragged through the control arm ear and score into the soft metal.
By using the spreader tool, you (A) LIMIT the amount of travel the cap can move inward on the pin, as the spreader is preventing the ear from bending inward and (B)   cause the torque to be applied to the inside thread ramp of the trunnion pin and the outside thread ramp of the (inside of the) cap.
(You cannot turn the pin in the cap, with the spreader tool, in place)

When you release the spreader tool, the ears come together slightly (.015) and relieve the torque which was applied to the pin, allowing the pin to rotate, with the caps firmly set in the control arm ears by the (torqued) interference fit.

If you torque the caps onto ears WITHOUT using the spreader tool, then you're pinching the pin in between everything. Since the pin is held fast by the kingpin pinch bolt that maintains the alignment, everytime the suspension travels up and down, the entire assembly will rotate, cap included. Since the control arm can't rotate, the cap will move inside the ear to take up the motion of the suspension, pivoting inside the ear, eventually wearing excess clearance between the cap and ear and will eventually beat it bigger as the damage progresses.

The following is a method to satisfy the requirement using a home-made tool, thanks to Jack Vines

I made a useable spreader from two pieces of 3/4" square bar stock 1' long , a 1" long 3/8" bolt/nut/2washers and a C-clamp. Place the bar stock side by side with bolt/nut/washers about 2" from one end, with the washers outside the bar stock. Tighten the nut finger tight. This holds the bar stock parallel. Put the short end between the ends of the A-arm. Put the C-clamp across the long ends in such a manner as it will pull them together. Measure the distance between the A-arm ends. Tighten the C-clamp, the bolt will act as a fulcrum and the short ends will open and spred the A-arm the specified distance. Install the cross-pin caps and release the C-clamp.

Here's my simple alignment prodecure Also see the file on INNER Rubber bushings..