As is tradition, I have an automotive project going much slower than expected. I thought I’d share my progress anyway. This is the installation of electric assist power steering in my 1986 Ford Mustang SVO.
Here is the steering column coming out after removing all the trim pieces and unplugging all the electrical connectors. Unplugging 30+ year old connectors without breaking the tabs off is no easy feat, but I managed to do it. It’s difficult, frustrating work at times.
With everything laid out on the bench, it’s time to go past the point of no return and cut the original steering column. The outer part of the column is just a hollow steel tube. There’s nothing too special about it, but when you cut enough of it to allow room for the electric motor, you also have to cut off a fairly beefy support bracket that helps locate the steering column. This reduction in support is addressed by a new firewall support bearing and a bracket that holds the electric motor at the correct angle. It’s acceptable, but maybe not as stout as the factory setup.
Inside the hollow part of the column, there is a standard 3/4″ DD-shaped steering shaft. It has to be shortened, and then notched. The DD shaft inserts into a coupler that is pre-welded to the shaft of the electric motor. Two set screws go through the coupler and fit into the notched section of the steering shaft. The set screws have to screw down almost flush with the coupler, because the outer steering column tube slides over this whole assembly.
I had some trouble fitting everything together, and I also managed to strip the set screw threads on the coupler. I ended up tapping the hole to a larger size, and everything worked out. In general, when you strip the threads in a hole, if it was a metric size to begin with, you can go to an SAE size thread that is just a bit larger, and if it was an SAE hole to begin with, switch to a metric size thread that is a bit larger. This lets you tap out a larger hole without increasing the size too much.
Time to test fit the assembly in the car. I was worried the motor might be too close to the brake or clutch pedal, but it’s not. Your foot has no reason to be that high on the pedal assembly, and the assembly itself doesn’t interfere with the motor either. This is going to come together just fine.
The biggest problem I have with this kit is that this assembly takes the place of what used to be the collapsible part of the steering column. I am going to address this by building a custom collapsible steering shaft on the engine side of the firewall. This is pretty easy to do with 1″ DD tubing that slides over the standard 3/4″ DD shafts. The collapsible steering shaft in combination with extra couplers and joints between the steering rack and steering wheel makes me reasonably satisfied that a hard crash won’t send the steering wheel through the driver’s seat. This is something I’m going to put more thought into.
I’m waiting for more steering shaft parts to arrive, and I also have all the electrical work to do, and I will post again when that is all done.