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I really didn’t mind the manual steering in my truck, although I think is was starting to bother my shoulders a little. Always looking for a reason to be in the shop doing something, I decided to attempt an electric power steering conversion. My objective in this was to make it a bolt in deal, so I could swap back to the factory setup if it was an epic fail. So I bought a power steering column and controller from a 2015 Toyota Prius, and I had a spare steering column from a truck I parted out a while back.
Seems like a good start.

I did some measuring of the column mounting area and the steering motor. It looked like the motor should fit in this area without interfering with anything.

I disassembled the Prius column, unbolted the tilt mechanism and bracketry. There was a pressed on tube over the input shaft end, cut this off at the motor housing (forgot to take a picture), so all I had was the motor and the splined input shaft.

A quick look at the inside, the input side has a steel gear of sorts with a plastic outer housing. The motor side has a steel gear. Should be strong enough to move my 33” tires.

I disassembled the extra steering column I had in my parts pile. I measured the column in my truck from just below the column mount to the end where the steering wheel is mounted, I don’t remember off hand what the measurement was. I cut the column tube to length. I also had a pedal assembly out of the parts pile, that I used for mockup. This made it nice, because I could figure this out on the workbench, instead of laying on my back in the truck. I slid the column tube onto the input side of the motor and mounted it to my test pedal assembly using the factory column mount. I tried rotating the motor in different positions looking for the best fit, and decided the best fit was for the motor to be clock into the 2 o’clock position.

Next was to complete the input shaft side of the column. The prius motor input has a telescoping splined shaft to the steering wheel, unfortunately this spline will not work for me, so I cut top of my factory steering shaft off (about 5”, should have done a little more) and the bottom 5” (roughly) of the prius shaft. This is hollow and almost a prefect fit for sliding the ¾” factory shaft into it.

I welded the shafts together by laying them in a piece of 1x1 angle iron and clamping them, trying to keep them straight. This seemed to work pretty good.

I slid the new shaft onto the splined shaft of the steering motor, installed the steering column tube over the shaft and assembled on the pedal assembly. You can see I temporarily installed the shaft bearing for center alignment purposes, and placed a couple of washers between the motor and pedal housing to create an air gap when it is final mounted.

Red383 wrote: ↑

Thu Mar 24, 2022 2:29 pm

I slid the new shaft onto the splined shaft of the steering motor, installed the steering column tube over the shaft and assembled on the pedal assembly. You can see I temporarily installed the shaft bearing for center alignment purposes, and placed a couple of washers between the motor and pedal housing to create an air gap when it is final mounted.

I don't know anything about these electrical power steering systems. Is there any kind of clutch between the motor and input or does this mean that, if one loses electrical power while driving, one must then try to turn the wheel to steer the truck against trying to spin the armiture through the gearbox? I have no idea how much additional force would be invovled. Have you tried it?

I hope I’m not stepping on Red 383 toes, but I have installed one in my D100. There is no resistance difference that I can feel between the manual factory steering and the Prius without assist. It really is a nice straight forward system. The guys have been putting them in old mustangs for years now. I still need to pull it and paint it and route the wiring better.

russtblue wrote: ↑

Sun Mar 27, 2022 6:57 pm

I hope I’m not stepping on Red 383 toes, but I have installed one in my D100. There is no resistance difference that I can feel between the manual factory steering and the Prius without assist. It really is a nice straight forward system. The guys have been putting them in old mustangs for years now. I still need to pull it and paint it and route the wiring better.

I take it you are still going through the factory Saginaw box? It sure looks like a cleaner install than the hydro assist and I'd bet it's cheaper. About the only downside I can discern then would be that it is an electronically constrolled device. Thanks for the photos!

Yes, I’m still going through the manual box.I bought the complete unit with the control module for 100.00. With the Bergesen lower coupler and the wiring I’m into it about 150.00. I like the electric part for a few reasons. It was a fairly straight forward installation, it is quiet, I get power steering even without the engine running. Red 383 is really doing a great job of showing a step by step install!!

wow that is cool
never thought of it
problem for me is don't think i could keep three on the tree
it would have to be mounted on the box
has any one tried that
i do want to do a power steering conversion ,think when i put wide tires on it ,it will be hard to park
keep up the good work
nutz

Good reply Rusttblue. Your install looks very similar to mine.

Lose of power and I am back to manual steering. No noticable effort than before.

Aaron

The factory column tube was slightly larger than the “hub” of the steering motor. To take up the gap, I found this exhaust connecter that was the perfect ID and OD. I cut off an inch or so of it and installed it in the end of the column tube and plug welded it in place.

I used two allen head bolts and threaded the holes on the end of the column tube, I drilled a dimple in the motor housing through the hole to seat the bolts. This fastens the tube to the steering motor. Also sand basted and painted the column tube.

At this point I pretty much was done with the top half of the column, re-installed the bearing in the tube, and the shaft would telescope up into the bearing (this becomes a problem later). I did reinstall the c-clip, spring and spacer below the bearing just like the factory. This basically sets the shaft at the correct “stick out” for the steering wheel to be installed.

Now for the lower half of the column. I was going to try to use the u-joints and shaft that came with the motor, but decided that would not work as well for my bolt-in concept, plus I would have bought more parts to make them work. I made a bolt on lower adapter using the bolt holes on the motor, I welded this to another exhaust tubing reduce that necked down to the perfect size for the factory column to slide right in. I drilled a hole on the bottom side so I could access the set screw on the Borgeson coupler.

I removed the factory column from the truck, and installed the motor with upper column. I measured the length that I needed to cut the lower part of the factory shaft to, and the lower column tube too. I cut the shaft and tube down and test fit them on the bench. I bought a Borgeson 312500 Steering Coupler, (11/16-36 X 3/4 Smooth Bore), to adapt the factory shaft to the splined output of the motor. I installed a bearing in the end of the column tube to support the shaft just like I did on my original column rebuild:

viewtopic.php?f=20&t=43168

I painted the steering motor. I painted the column tube, installed the bearing, and slid the shaft in. I roll pinned the ¾ shaft to the Borgeson coupler.