When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Toyota P/S With a Stock Column In a '48-'52 Done the RIGHT Way
Even though I research everything endlessly before I dive in, I ran across some issues with the Toyota power steering box installation in my '52 F-2 that I had never heard of and wasn't prepared for. For that reason, I wanted to document here in my typical excruciating detail what I ran into and what I did to fix it. Hopefully this thread will be a resource that will save somebody else some frustration down the line and make their install go a little smoother - or at least educate them on what to expect.
I decided early while planning my build that the plan and theme for the truck required two things without compromise: retaining the stock steering column and pedals in their original locations and power steering. Since I'm sticking (sort of) with a straight axle in front, the Toyota steering box swap that I've read so much about seemed to be the logical choice for the power steering conversion.
Much has been written about this swap and it appears that the Toyota box is an almost ideal swap candidate - for a '53-'60 truck. The box is very similar in design to an original '53-'60 manual box and once you purchase the correct mounting bracket, it bolts right in and aligns perfectly with either the stock steering column or any aftermarket column you might want to swap in with it. The alignment is so good that you can use a coupler to attach the stock steering shaft without a universal joint. There is much less written about putting one in an earlier truck, but I had assumed that the logistics would be virtually the same. I found out pretty quickly that stuffing one of these into a '48-'52 truck and keeping the stock column is a bit more complicated.
The proper Toyota gearbox for this swap is getting tough to find and pricey when you do. The going rate seems to be $200-$300. I managed to snag one off of eBay for $75 that a dyslexic seller had listed with spelling errors in the title. I also needed a mounting bracket. Mid Fifty F-100 Parts is currently the only vendor selling a mounting bracket specifically for the Toyota box in a '48-'52 truck. I was impressed with its construction from the photos that I had seen. It seemed a little pricey, but my shop time is short these days and it was worth it to not have to fab one, so I went ahead and pulled the trigger on that too.
When the gearbox arrived, I compared it to the original gearbox still installed on my '52. I noticed an issue right away. The Toyota box is designed and built the same way that a '53-'60 box is - with the worm shaft above the sector shaft. That is why it fits so nicely in those later trucks. The original Gemmer box in the earlier '48-'52 trucks is constructed with the worm shaft below the sector shaft. The result is about a six inch difference in the location of the worm shaft and where the steering column connects. Hmmm.... this could be a problem! The difference in design is obvious in this picture with the gearboxes beside each other:
But that wasn't the only issue I noticed. The lateral location of the worm shaft was considerably different as well. This meant I was going to have a misalignment to correct in two different planes. This pic taken with the ends of the sector shafts roughly lined up illustrates the lateral difference in where the steering column needs to connect:
At this point, I figured that it would be best not to panic and wait and see what I had to work with when the Mid Fifty bracket arrived. Here is their bracket fresh out of the box:
Beefy! It's a very nice piece. It was cut and machined from a single slab of steel and it's designed to attach to the frame through three existing holes in the rail. Here it is with the box mocked up in the chassis:
I had to shorten my stock column and cut the worm shaft off of the original steering box next. I knew I would have to have at least one joint and probably two, so I cut the column as close to the bottom of the toe board as I could to leave myself as much room as possible to work with between the column and the gearbox. Let me add a short sidebar here - AXracer and others have mentioned that all you need when modifying a stock steering column for use with a Toyota box is a piece of delrin, wood, silly putty, or some other such thing to use as a makeshift shaft bearing at the base of the column because the shaft only turns at low speed and you just need to keep the shaft centered in the column tube. They claim that column saver kits are an unnecessary waste of time and money. I respectfully state that that philosophy is incorrect. You need a column saver with a Torrington thrust bearing in it because there is a spring underneath the steering wheel that keeps the cone wedged firmly into the upper column bearing. There must be something for that spring to pull the shaft against at the base of the column to make everything function correctly as a unit with no friction or vertical movement of the shaft. That's why you will see a column saver installed in the following pictures of my shortened column. I adapted the stock shaft to a 3/4" double D shaft inside the tube just above the column saver. The column saver was purchased from CPP and waseasy to install. $70 well spent!
Here is what the misalignment looks like in both planes with the box installed on the Mid Fifty bracket:
Wow. That's a lot of misalignment and not much space to correct it in. I wasn't getting the warm and fuzzies at that point. I knew some precise measurements were going to be necessary, so I stopped there to level the frame front to back and side to side. I got the top of the frame rail level to within a 1/10th of a degree all the way around before I took the following measurements. Here is the mounting angle of the stock column through the original location in the floor with the stock column drop:
And here is the angle the worm shaft is positioned at with the Mid Fifty bracket:
So the Mid Fifty bracket lays the box back 10 degrees from the stock column angle. After looking things over at length and studying the operating angles of the common u-joints available, it became clear to me that there was just no possible way or combination of parts that would allow me to connect the stock column to the Toyota box using the Mid Fifty bracket. Your typical steering joint will operate at up to 30 degrees, but I would need two joints operating at much sharper angles than that in a space smaller than two joints will physically fit into. I could use a double joint in that much space, but the angles were still far too acute. The box needs to lay back more. A lot more.
The Mid Fifty bracket does lay the box back enough that it would be easy to hit it with an aftermarket column mounted in a slightly elevated position at the toe board. It is a seriously nice piece and I would highly recommend it for use in that situation with an aftermarket tilt column. But it just won't happen with a stock column.
So what to do, what to do? Nobody else was offering a Toyota bracket for a '48-'52. I was left with building one. I looked at 3 or 4 different designs of home built brackets that I had saved pictures of, but all of them mounted the box at a similar angle to the Mid Fifty bracket. I needed to start from scratch. I was shooting for something that would attach the box at an acceptable angle using the 3 original mounting holes and not require drilling new ones. I won't go into the whole creative process (mostly because I hate fab work and I'm still emotionally scarred from the ordeal), but after 3 revisions, here is what I've come up with.
It ain't real purty yet, but I haven't had a chance to blast and paint it. The sweet spot for the worm shaft angle turned out to be 16 degrees. The flat iron is 3/8" x 2", the block for the bottom bolt is 1" x 1" x 2" and the upper blocks are 1" x 1 1/2" x 2". All the hardware is 7/16" fine thread. Here's what it looks like in the chassis:
And I did need to use a double joint. It was the only way to get it put together in that small amount of space. The joints are still operating at close to their maximum angles, but it works and the shaft rotates smoothly. The side to side position in the frame was tricky. If I moved it too far outboard, the joints would start to bind. Too far inboard and I started running out of room for the pitman arm. I determined that the ideal location was with the centerline of the worm shaft 4 1/8" from the outside of the frame rail. Here's what the end result looks like with everything connected:
So there it is. If I had it to build over again, I think I could have bent the frame up out of one singe piece of flat stock and it would have looked a little cleaner now that I know all of the measurements, but I'm still pretty happy with it. My crappy phone camera makes the welding look like hell for some reason, but my new Lincoln PowerMig really did a nice job. Its a pretty decent looking piece and will be plenty stout.
I have also been following the many threads regarding this install. Thank you for pointing out the major differences between the two vehicles, (F1 and F100).
Since I'm not at all versed in angles, I am having a hard time understanding why it was more advantageous to install the box at 16 degrees instead of trying to match the columns 49 degrees?
Am I not correct, that doing so would have resulted in only one alignment issue to overcome with the U joints? Is there something I'm not seeing, in the pics that caused you to go to a more horizontal plane?
Very well made and well executed conversion. Your attention to detail is something that many leave behind. Well done! I will be watching for the updates.
it looks like the mounting bolt heads are in the way of the pitman steering arm. They stick out into the area of the splines on the shaft. Is that the case?
My hats off to you for an excellent tutorial, and nice clean Toyota P/S conversion. Your explanations and accompanying pics helped me understand a lot of things that previously eluded my limited mechanical abilities. Rep, Rep!
pbsdaddy - The issue with mounting the box with the worm shaft parallel to the steering shaft is the short distance between the two. Typical steering u-joints start to bind when operated at over 30 degrees. The short distance between the ends of the shafts forces the angles to be greater than that. The u-joints will just not physically fit in there or operate. Here is a pic that I had taken with the box still mounted on the Mid Fifty bracket. The double joint was installed on the worm shaft and it clearly will not flex far enough to connect with the column. This was what dictates that the box lay farther back.
Muppy1840 - I'll be producing them for sale starting the day after my truck is done, the house is remodeled, and I cross off the last item on my honey-do list! Seriously though, I've been in contact with Diane at Mid Fifty about this. She was very concerned with what I ran into and why their bracket wouldn't work. Ultimately, I'd love to see Mid Fifty have their fabricator build a version of my bracket and sell it specifically for stock columns. I've offered her my measurements, dimensions, and sketches if she is interested.
timboy - The pitman arm fits and clears - just barely! The angle of that one photo gives the illusion that there is less room than what there is. The stock pitman arm actually had a little dogleg in it to clear that bottom bolt.
Thanks for all the positive comments! I did edit my post with the distance from the center of the worm shaft to the outside of the frame. I try to keep all of my build progress in my build thread, but I may update this thread again later with a completed installation photo. But that could be awhile. First I've gotta mount the axle, build the linkage, set the engine, blast and paint the frame....
Very nice job! Great info about angles with a stock column. Can I talk you out of a copy of the info you offered to Diana? I would like to draw it in AutoCAD.
I installed this same steering box in my 49 F1 using the bracket that Mid 50s sells, same one that you show in pictures above. I modified it by cutting the longer of the angled arms off and welding it back at 90 degrees to the center bar. This gave more range to turn steering box assembly in frame rail. I moved steering column firewall support by elongating hole in firewall a little for better alignment with steering box. When done, I only needed one u-joint, splined one end to round on other. Welded round end to column shaft.
12-07-2016, 01:55 PM
) with a straight axle in front, the Toyota steering box swap that I've read so much about seemed to be the logical choice for the power steering conversion.
), but after 3 revisions, here is what I've come up with.
, So when are you going to start selling them? 
Seriously though, I've been in contact with Diane at Mid Fifty about this. She was very concerned with what I ran into and why their bracket wouldn't work. Ultimately, I'd love to see Mid Fifty have their fabricator build a version of my bracket and sell it specifically for stock columns. I've offered her my measurements, dimensions, and sketches if she is interested.
