{Chrysler 300} 1964 300K Steering Isolation Coupling and Grounding

Here is my solution for the issue of the copper ground strap on the 1964 Chrysler.

For the steering box side, I have a stainless steel shoulder bolt that is resting on two saddle washers in place of a solid pin, split pin or a cotter pin. The shoulder bolt (McMaster Bolt: 94035A172 Nut: 90101A009) is 3/16 and fits the existing hole. The saddle washers (Aircraft Spruce: 04-00927) makes the tube flat and gives the shoulder bolt a good crush and a good ring terminal contact.

On the steering worm shaft side of the issue, I am going to use a stainless pipe mount collar (McMaster: 2236T22). These are for a 1-inch shaft and need to be dressed just a little to bite the 0.900 worm shaft. {Thanks, Bob, for the measurements}.

Since the worm shaft is at my place out of town, I used a tapper I have here for trial fitting. I will use a 2- or 3-inch length of wire from the box side to the shaft side, but you get the idea with the tapper in the photo.

The measurements, the stainless-steel shoulder bolt, saddle washers, nut and ring terminal show it will fit. The steering column tube is 2.641 OD at the bottom and the above assembly is a little less than 2.100 inch. That means that there is about, accounting for tube wall thickness, 0.500 inch clearance dived by two or a 0.250-inch clearance between the bolt-nut and the column inside wall.

However, since I do not have the column here in San Francisco with me, my only concern is where does the column go from that 2.641 OD down to the 2.131 OD ? I hope it is long enough so that it narrows down above where I need it to be.

Since once it is in place it cannot move, that should not be an issue. The head of the cotter pin that was in there sticked up almost as much. One could omit the saddle washers and get a narrower shoulder bolt. I wanted to spread any load over a larger area than at the point of the hole alone and to give the ring terminal more electrical contact area. The saddle washers are aluminum as I could not find them in steel. I will spray a little DeOx on them before I tighten them down.

Over the weekend I intend on installing this and will take a couple of photos before I slip the column down. I am also taking along some split pins and new copper ground strip just in case something will not clear as a backup plan.

Best, James