How to Add Electric Power Steering to a Willys

I would like to thank pts211 for the idea on this electric power steering conversion from this thread. I carefully read through it thread, watched his videos, then jumped into my own.

For the most part, I found the EPS conversion relatively simple. Buy a Toyota setup, weld some shafts together to fit the original steering wheel, weld an adapter to the oem steering box, then the conversion is practically finished. However, there are some shortcomings I experienced that I’d like to share with those wishing to jump into this endeavor:

• When you remove the stock steering column tube, you expose the stock Willys steering box to the elements. The top of the box is not sealed at all. This isn’t an issue in stock forum, as the column tube covers the box, and the steering wheel w/ horn setup covers the tube. All is sealed. When you adapt EPS, you remove the horn and the column tube. Water and debris can run right down into the steering box. Thus, you’ll modify the flange that bolts on top of the steering box. Why? There isn’t enough room between this flange ID and the steering column shaft OD for an oil seal to fit. By turning down the ID of the flange, you make room for an oil seal.

• Stock Ross steering columns are almost always bent at their base above the worm gear. I fear these bent columns will inevitably eat away at the oil seals. The future will tell.

• When selecting an EPS unit, I strongly urge you find one that has mild steel u-joints. I picked a 2009-2013 Toyota Corolla unit. I wasn’t aware the u-joints were cast iron. Thus, I couldn’t weld the bottom u-joint to my steering box worm gear, and was forced to make adapters to hold it together. This was very time consuming that required a machinist, and it could have been surpassed with a different u-joint.

• With a stock steering box, EPS is a band aid. It absolutely improves steering characteristics. Eliminates bump steer. Easy turning while the Jeep is moving above 1 mph. If you only drive your Jeep on the street and light to mild off-roading, you will absolutely love this setup. For those of us who enjoy driving their Jeep in places they don’t belong, EPS with a stock box is slightly underwhelming. I brought mine to Moab, Utah to wheel with the gang at Easter Jeep Safari. With welded front and rear axles, my turning radius was greatly reduced. Often times I had to make 3-point turns where open differentials do not. In these situations, I absolutely loved the EPS unit as it make turning the wheel very easy. My arms were not exhausted after a week of wheeling.

• The only time I couldn’t turn the Jeep is when the wheels were bound on big rocks. If you watch anyone with hydraulic power steering, they can actually wiggle their entire Jeep off rocks by turning the steering wheel. A Ross steering box with EPS will not do this. In fact, the EPS doesn’t help at all. I cranked as hard as I could on the steering wheel, but it wouldn’t budge at all. This isn’t a bad thing, as the Ross box can’t handle those extreme forces anyways. When against rocks, pretend you don’t have EPS at all.

Unexpected benefits:

• When adapting EPS, you have the opportunity to place the steering wheel wherever you want. More stomach room, or more visibility? Now is the time. I personally adapted a smaller 15” steering wheel as shown in the video for the best of both worlds.

• EPS can be turned on/off. If you feel the Jeep is too twitchy on the highway, simply turn off the switch that operates the EPS unit. With the 15” wheel and slow speeds, I didn’t feel any need to shut mine off. It wasn’t twitchy on the highway at all.

• Adaptability to other steering boxes. For those who desire a Ford reverse steering box, or Saginaw, but don’t have room for a powered box with the factory 4 cylinder, you can achieve ultimate steering capabilities by adding EPS to a non-powered box. If you have a V6/V8, you can still use this combination to prevent messy hydraulic powered boxes.

• If the EPS unit fails, you simply revert back to normal non-eps steering. No power steering box whine, no additional load to a stock system. Just pretend the EPS was never there.

Final Thoughts

Since I already built my Jeep with the stock Ross box, I don’t have a strong urge to redo the system with a Ford box at this time. It satisfies 90% of my driving needs, which are on the far extreme end of a Willys Jeep. I have the perfect balance of an “old vehicle” where steering is limited when bound against big rocks, but have the modern amenities when driving in all other terrains. In the far distant future I would like to adapt the Ford reverse box to use with my L134 engine. Overall, I rate the EPS conversion as an 8/10.