The Stovebolt Site Forums The Shop Area Driveline Power Steering Conversion with Toyota Box

I want to convert my 1953 3600 to power steering using a Toyota steering box. I bought a functional unit from a 1984 Toyota 4-Runner about 15 years ago. I searched the site and every link I found within the threads to installation details are broken. Does anyone have any information they can share on this conversion? Thanks!

I borrowed the picture of a 1953 from Jalopy Journal. It's not mine but it's a good example of things that can go wrong after steering modification. The priority is good steering and good brakes. If your insurance company finds out that you personally modified your steering, they will be reluctant to pay for any damage (property or personal). I'm sorry if all this seems like I'm picking on you.

You probably could answer your own posting question. If the Toyota steering box was a "hot item" today we would expect to see a lot of postings. I believe most folks go with the Saginaw box. GM parts on GM trucks.

You have a steering box but you'll need a pump, special mounting brackets, new hoses, CORRECTLY DESIGNED pitman arm & drag link and something to connect to the steering box (typically shortened steering column, column bearing, coupling, sectional shaft etc.). Installing a used power steering pump and steering box is a potential for future problems so you will want to rebuild them. I humbly suggest you look at a complete kit with the engineering already designed into it (example only https://www.classicperform.com or https://www.performanceonline.com etc.). If funds are tight, you can buy the smaller kit (less pump and box) and find known good used pump and box.

Before spending money on new steering parts, you definitely want to make sure your front and rear leaf springs, shackles, spring eyes, king pins and tie rod ends are not worn. They usually are. If you put power steering on a worn suspension you just magnify your problems (steering-feel and handling).

Eventually the steering wheel diameter may seem too big and you may wish to reduce the size or get another one with a smaller diameter.

You would be removing heavy duty 1 ton components to install light duty mini-truck type of components. If anything, it might be better to upsize?

metric to SAE conversion problems also?

If i remeber correctly,the toyota box that has been used in the past,and there are install kits available, is the Landcruiser box. It has basicsly mounts in the same location as the oem box,havent heard much about it recently,i have seen an AD with one install years ago. The most common is the gm saginaw conversion. I have all the needed parts to install on my 54.Someday soon ill get it done!

I have installed several "Toyota" conversions on TF trucks including a 57 3600. I also installed one on 56 Ford F100. They work well.
I did the conversion to my 56 3100 in 2000 and has been trouble free. The only "metric" issue is the hoses which are easily made up with metric on the box end and SAE on the pump end. It's a non issue.
There are a number of aftermarket suppliers that have re-engineered the box so that it mounts directly to the frame eliminating the mounting bracket. The box I used was from a 84-87 Toyota 4X4 pickup. It came as a kit with the pitman arm, drag link, mounting bracket, steering box connector, and hardware. I modified the stock column.
HOWEVER, I do not know anything about installing one on an AD truck. The only suggestion I can offer is to contact some of the aftermarket suppliers and see what they have available.
The original box on an AD truck mounts on the upper part of the frame and the TF truck box mounts inside the frame. From what I have seen the Saganaw conversion works well on an AD truck.
Fred

Excellent advice! In 40+ years of seeing and paying losses like this, I can reiterate if your insurance company discovers after a loss that you took it upon yourself to re-engineer your vehicle's steering or braking and didn't tell them and let them (or usually a qualified outside party of their choosing...like Jerry for example) inspect it, the likelihood they'll cooperate with a claim is not good. Usually they'll reserve their rights...meaning they'll send you a letter saying they'll defend you initially but may later deny coverage (depending on their investigation). Best situation is that you bought a kit (from somebody with a corporate insurance program) and had it installed (by an experienced professional who also has insurance).

I've seen enough "deathtrap" steering and suspension modifications on resto-mod vehicles to make me really spooky about IFS and rack and pinion modifications a lot of guys accept as routine. Just because some money-grubbing hotrod shop sells a "kit" that's supposed to work doesn't mean they've got the engineering expertise to make sure their cobbled-together assortment of mismatched parts is going to be safe, especially if the guy installing it welds it up after catching a bad case of "Budweiser Fever"!
Jerry

I suspect most of the suppliers know less about steering fundamentals than Jethro Bodine. But most of these suppliers (I'll be careful not to say all of them) have a commercial insurance program including an umbrella cover...and your auto insurer is going to start looking for subrogation possibilities about five seconds after they figure out your front end isn't what GM designed for your vehicle. If they decide to cover the claim at all (and subrogation possibilities will be high on their list of reasons they might want to grant you coverage). If your insurer can claim the seller (we'll call that operation Speed Crazy Paradise) and the product they sold caused or even contributed to the problem, then you can bet your bippy your insurer will drag him in. When Speed Crazy's insurance company gets involved, they will drag in the maker of the kit (we'll call that operation Big Donkey Head Front Ends), and then everybody will get to write a check for something. Unless of course somebody in this chain agreed to sign a waiver of subrogation in order to get a cheaper price, faster delivery, captive market protection or whatever. Then things often start collapsing like a wet taco. Naturally it won't work well if your auto insurer (let's call them Lloyds of Lubbock) also insures Speed Crazy and Big Donkey Head. And I've seen this happen several times.

Unfortunately, the big loser in the scenario described above is going to be the soccer mom with the minivan full of curtain climbers who had the extremely bad luck to be in the middle of that tight S curve Joe resto-Mod didn't see coming when he topped a hill about 20 MPH faster than his "It steers pretty good in a straight line" IFS was able to negotiate.

Now, in the interest of full disclosure- - - -some of the stuff that's rolled out of my shop would send an insurance underwriter screaming in terror and rolled up into a fetal position sucking his thumb! How about 500+ horsepower shoehorned into a 102" wheelbase vehicle with three different-sized tires, and a hunk of motorcycle chain connecting the steering wheel in the center of the dash to the steering shaft. Then bolt an inverted airfoil on top and do the "Go fast- - - -Turn left" thing on a slippery surface made up of wet clay and chert gravel in a quarter mile oval! Of course, everybody out there is a willing participant in the madness, and if the soccer mom is there at all, she's up in the grandstands cheering her man on, not sitting crossways on the back straight!
Jerry

Thanks everyone for the input and for the warnings. I have been wrenching/fabricating since I was a teenager - over 40 years. I have modified the steering and suspension on several Jeeps without a single failure. I am probably more anal than most of the guys on this forum. I absolutely want power steering.

I first registered on this board 18 years ago when I inherited my 1953 3600, the Toyota box conversion seemed to be newish. I thought it was an interesting concept, so I bought a used box for $20. Today, these Toyota boxes are scarce. A used box is $250+ and a reman box is $400 - $600 if you can find one. The Toyota box conversion seems the simplest requiring the least amount of modification to the factory steering system. Unfortunately, the site search function will only allow a search of posts newer than 15 years. I did find some threads with broken links - one with a broken link for instructions from Keith Lebo. I could not find contact information for Keith Lebo. I did find an obituary for a "Keith Lebo" from Connecticut who enjoyed working on his old truck - don't know if it's the same gentleman.

I believe (maybe incorrectly) the Toyota box conversions stopped because of the scarcity/cost of the Toyota box, not because it didn't work correctly/safely. I don't really like the Saginaw box conversion outside of the frame rail design using 2 u-joints. This setup looks more sketchy than the Toyota box conversions I've seen on the web - but it's been a long time since I've seen those pics.

For comparison purposes, the stock Chevy box is 5-1/4 turns lock-to-lock with 70 degrees rotation of the sector shaft and the Toyota truck box is 4-3/4 turns lock-to-lock with 85 degrees rotation. The input shaft of both boxes are about the same diameter - the Chevy is just a few thousands larger. The sector shaft of the Toyota box is over 1/8" larger than the Chevy 3600 box. I just checked both. I have a spare Chevy steering column/box assembly.


Here's a Youtube video to a Napco Advance Design Toyota box conversion


Here's a link to a photo of said Toyota steering box.
https://www.rockauto.com/info/450/5911-a__ra_p.jpg

As with the Saganaw steering boxes there appears to be some differences in Toyota boxes as well.
The Toyota box in my 56 has the same number of turns lock to lock as the stock TF box, 5 1/4 turns. There is a possibility that the
4-Runner may use a different box than the pickup.

A friend purchased a Toyota FJ40 some time back. It had been converted to a Chevy engine, TH400 trans along with a fast ratio Saganaw box. The steering was probably from a Z28 or Firebird. It was flat out scary to drive, big tires, high roll center, and instant steering, yikes. He ultimately sold it.

There are numerous insurance companies out there that specialize in street rods, hot rods, and modified classic cars & trucks, we all use them. They intentionally insure these vehicles with full knowledge that almost everything is modified. I have not heard of any issues getting settlements for accidents. Many are under insured but that's another issue.
Fred

The 4-Runner and the pickup boxes are dimensionally the same and will bolt in place of each other. They share the same LARES part number on Rockauto. I was not aware the boxes were available in different ratios.

Buyer's Guide : LARES 5911 Steering Gear
TOYOTA 4RUNNER 1984-1985
TOYOTA PICKUP 1981-1985

Just a couple of points for clarification, Fred. First of all, your comment about under insured is a very good one. More people ought to think about that, shouldn't they? Not having adequate limits of liability at the time of a loss is a really bad situation for everybody involved.

All the companies people refer to as insurance companies are actually insurance agencies that place business with insurance companies (and those companies have created these specialty insurance programs). American Modern Home Insurance Company is probably the main writer of coverage on non-standard vehicles and I actually have both a personal knowledge of this company and a good deal of respect for them. Very professional group of people. They underwrite both standard risk and high risk situations and do it very well and professionally.

But all of those specialty policies contain some specific limitations---for good reasons. Now if you're driving your truck/vehicle as I do...meaning if I want to drive it as daily transportation, I do and I have no coverage limitation. If I want to drive it for the use it was designed, I do...meaning if I wanted to haul bags of concrete from Dallas to Seal Beach, I'm free to do so. My insurer might think it odd, but they wouldn't care nor would they limit my coverage. In fact, if I want to pretend it is 1952 and drive my truck all over the country exactly as I would have done back then, I can do it. But if I bought one of those little hot rod plans I couldn't do any of that. I don't buy physical damage coverage, Fred. For a vehicle this old and driven the way I do, it doesn't make sense. The cost would be hideously expensive. If it was a parade only truck or a trailer queen, that coverage would be really cheap, but my main concern is liability. If I hit somebody, I want to have as high of a liability limit as I can buy.

Some people with a lot more financial sense than I had, a lot of years ago explained insurance to me this way - - - - -"As long as you don't have a pot to whiz in, or a window to throw it out of, you don't need a lot of insurance- - - -nobody's going to go to the trouble to sue somebody with nothing to take". As we get older, and accumulate more assets, insurance coverage becomes a lot more important. I'd hate to lose my home, and the 100 acres of Tennessee it sits on, plus all my big boy toys over an automobile accident, so my insurance coverage needs to prevent that kind of loss from happening, plus a little cushion to account for a "runaway jury" in case some ambulance chaser tells a sufficiently heart-rending story about what a worthless piece of trash I am for injuring his client! The premiums to assure that kind of coverage might not be fun to pay, but the alternative is downright terrifying!
Jerry

Jon/HRL,
I absolutely agree with the aforementioned. While I did drive my 56 to work occasionally it was only about 4 miles. Most don't drive them every day and insure them accordingly. To me the possibility of theft, damage, & liability out weighs getting out there with the crazies. If you loose one of these vehicles it's not just another Honda.
Fred

Here is a hint, Fred. You live in California and unless CA law has changed since I retired, every insurer doing business there must offer you the ability to buy UM (uninsured motorists) coverage, and you have the added benefit of being able to buy UM as bodily injury and property damage. Buy as large of a limit as you possibly can...and I think you can also be covered under UIM (underinsured motorists coverage) for bodily injury and property damage. UM/UIM is much less expensive than buying one of the hot rod policies and there are no limitations on use of your vehicle or the age of it or anything. None at all. And like physical damage, this is first party coverage...meaning you collect from your insurer after a loss. So my suggestion is this: buy UM and UIM, insure your truck under your family auto policy for the same liability limit as you insure your family auto. Then increase the liability limit under your homeowner's policy to $500,000 (this is cheap coverage) and buy a personal umbrella for $1,000,000, $3,000,000, $5,000,000 or whatever limit you want. Here is another bonus you have: in California your personal umbrella coverage can include UM and UIM. When you've done all this you will have (1) spent less money and (2) you'll be able to sleep like a baby because you'll be well covered for almost any possibility. And the neat thing about your truck is you will in effect have physical damage cover (except for hail, flood, acts of God, theft). If some crazy hits you...even if that crazy has no insurance or only the state minimum limits, you have coverage and it will pay for loss to your truck. My experience has been these vehicles are almost never stolen if the owner takes reasonable care. Especially today. My experience has also been they're almost never damaged by hail nor flood or does one spontaneously burn. Damage from falling objects is also very uncommon. If your vehicle burns up because your garage or house caught fire, it will be covered as long as you've made your insurer aware you have a special interest vehicle so the proper limit can be available. And if you took your wife to dinner, parked in a parking lot or garage and something happened, that's liability of the owner of the garage or lot, the restaurant, lessor, somebody. I hope this is helpful. There really are ways around the challenge of insuring vintage vehicles. My liability coverage is with GEICO and they don't mind covering them at all. They would prefer you limit your mileage to 6000 miles a year, and that is because they're giving you a break (discount) on your liability rates. If you plan to drive more than 6000 miles a year (which I do), just tell them. They may increase your rates or they may not if you've been a customer for a while. USAA, Progressive, Hartford and other insurers do the same thing. From their standpoint, the fewer miles you drive, the fewer are the chances you're going to hit somebody. Jerry is 100% correct in what he said, by the way. The last thing you need is some attorney in some courtroom trying to take away your assets...and they can. Or...even worse...you don't want some attorney deciding the modification you made to your vehicle constitutes what is called vehicular negligence which in turn led to vehicular homicide. Good luck. I'd find a really good insurance agent. Preferably one with some white hair who has been doing this long enough to know the ropes.