IFS Steering Gear Box on FJ40 Power Steering Conversion

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Jan 12, 2012
Ok.....I'm Playing around here.

I am looking at taking an IFS 86 Steering Gear Box and attempting a Power Steering Conversion on a FJ40.

I was getting ready to do a mini-truck power steering conversion however partially through I looked at an 86 ifs gear box that I had laying around. Started to think if anyone had ever attempted this. Believe me I searched and searched and found where everyone says you can't do it you need a 85 to 79 but not what I was trying to attempt.

Here is what I was thinking. (Bear in mind I'm drinking scotch and water now and lots of it!!!)

Take the box mount it between the upright fender support and the old box mounting bracket. Align it to match the steering column path (I built a prototype bracket that would need to be welded to the frame but would also need to build an extension for the column) and reverse the pitman arm so it faces forward (ifs have reverse movement).

Build an arm that mounts on top of the driver's wheel (on the four bolts that hold the arm that I don't know what is called) that comes backwards. Cross over with (I apologize steering experts because I don't know what this rod would be called.) a rod to the pitman arm. The pitman arm would be at an angle which could be accomodated by the two ball joints on the pitman arm and on the arm backwards from driver's wheel. It appearst that it might just have enough clearance to manuever.

Surely someone has tried this before..(I hate laptops too much typing and retyping. Just erased an entire paragraph. It could be the scotch but doubtful)

Hit me with a 2x4 and call me sally in the morning but wouldn't this reduce a lot of steering crap up front? I know very little if anything about the steering boxes.

Does the ifs take a big load off the box and this being a fixed axle would be too much? I keep coming back to the thought that the weakest link has to be the joints so the box should hold.

Would not taking the long rod from the box to the passenger side out of the equation strengthen the system?

Like I said.....Let me know exactly how stupid of an idea this is. Tell me where I am not thinking correctly and where I didn't think it through.
Your going to need a diagram, because your description is extremely confusing.

If you use an IFS box, I would recommend running one closer to the firewall, with the pitman arm mounted backwards, a 4x4 labs crossover (mounted backwards, with tie rod in front) and the drag link going behind the passenger side knuckle.

But at the end of the day, its a very very hard box to fit. Your alot better off running an fj60 or fj80 box.
Many other PS systems have been done. Saginaw, FJ60, minitruck, etc. The gotcha's have been figured out. Plenty of parts available from lots of sources for those setups.

If you're looking for a good steering system for a rock crawler running big tires, go saginaw.
If you're looking for something that will be nice to drive on the highway and eliminate the slopp linkages, center arm, etc, go FJ60.
Your going to need a diagram, because your description is extremely confusing.

If you use an IFS box, I would recommend running one closer to the firewall, with the pitman arm mounted backwards, a 4x4 labs crossover (mounted backwards, with tie rod in front) and the drag link going behind the passenger side knuckle.

But at the end of the day, its a very very hard box to fit. Your alot better off running an fj60 or fj80 box.

The confusing description could have been the scotch!!!! It might help if I took the time to learn the vocabulary.

I have it pretty close to where the original box is located. However trying to get it towards the rise in the frame for the axle for clearance of the pitman arm.

Yeah, it's hard to fit. I'm just playing around. Took the week off to spend time with the wife and kids.....That didn't happen. So far have been down at the factory working every day. Was going to work on the fj40 today but spent most of the day working on a forklft.

Thanks, for the response guys. I was hoping someone had tried this before. I will take a look at 4x4 labs, I've been on their website and that's a good place to look. If anybody has ever done it they probably have. Spent hours searching mud about it but didn't think to look there.

I think it can be done. If so I will post pics. If not then it was an experiment. I will have to build/mount the brackets to determine clearance for the pitman arm as I will be doing myself.

If I don't like it I can always go back stock, mini-truck, fj60, or saginaw.:beer::beer::beer::beer::beer::beer:

IT'S 4th OF JULY EVE.......YOU KNOW WHAT THAT MEANS:beer::beer::beer::beer::beer::beer: (They need a scotch and water icon)
IFS Gear Boix on Frame

As I mentioned before I am playing around here. I realize there are easier power steering solutions.......But what fun would that be. Someone told me it couldn't be done and I wish they would have said that it would be terribly difficult, too much time but they didn't have to say it couldn't be done (Wasn't anyone from this website find everyone here very supportive).

The other reason I wanted to do this is that here in Kansas you can't find 79-85 gear boxes. However you find lots of IFS gear boxes. All parts came from an 86 IFS, 93ish four runner, 95ish toyota truck.

Welded a plate 3/8" on frame approx. 8" long to mount gear box. Had to drill out holes and weld the bolts/studs in for mounting.
gear box on frame.jpg
Drag Link

I think this is called a Drag Link. But anyways cut the joint off the existing crossover Drag Link on my fj40 and welded the female end on that mated with the pitman arm from the IFS. I left the threads on in case I ever wanted to adjust anything. Sorry if I have the vocabulary wrong.
drag link.jpg
Steering Shaft

Since I mounted the gear box so far forward (Didn't mention that I had another position for gear box and I didn't like it. Didn't realize I didn't like it until I had already cut my steering shaft.......You get the idea).

Anyways, I had to build a steering shaft to actuate gear box. This is a picture of the lower u-joint, followed by middle splined shaft connection, and then the upper u-joint
lower u joint on steering.jpg
middle spline steering shaft.jpg
upper u joint on rag joint.jpg
Rag Joint

Stole a rag joint and all the splne shafts from a 95ish toyota truck. Here are a couple of pictures of the upper part of the rag joint welded to the steering shaft that goes through the steering column.
Steering rag joing.jpg
rag joint steering.jpg
Steering Shaft

The spline shaft I got from the 95ish truck was only approx. 4" long. Therefore I cut it in half and welded a 1/2" square rod to each end. I liked this approach vs. welding a solid shaft on each end, as the splined shaft has a "keeper" on it as long as the bolt on the female is in. Meaning the shaft will only travel so far if the bolt loosens for some reason. The other thing is that it is nice to be able to tear something apart several years down the road. The other factor is that you have a little play on dims.
shaft with splines weld.jpg
welded spline steering shaft.jpg
Power Steering Pump

Here is where I really really wished I had ordered parts for the power steering bracket. But I didn't and the thought process was that I could build a bracket faster than I could order one. Still would have been a whole lot easier if I had preplanned and ordered the brackets.

Used a powers steering pump off a 350 GM and ordered a pulley. Had the hose made up locally.
pump bracket.jpg
front of pump.jpg
If you notice in this picture I had to cut the shock mount to enable clearance for the steering shaft. My plans are to go back and weld a reverse teardrop plate on the backside of the shock mount to transfer loads back to frame and avoid snapping/cracking my mount.
shock mount cut.jpg
For what it's worth, All in all I'm very pleased with the results. I have yet to take it off road, I want to fix the shock mount first, but quite happy with how it turned out.

I hope someone finds this useful if they want to do it. I would suggest going the route of the saginaw, fj60 or mini-truck.

Total expenses:

Gear Box $75
Hoses/Fittings $35
Pump $40 (Guessing here as I already had one)
Pulley $17
Belt $10

Total $177 plus brackets (HIGHLY RECOMMEND)

All the steel I had laying around.
I am going to repost on this thread in hopes that I may get some responses.

One of the reasons I did that conversion is that there aren't many mini trucks gear boxes around here and fj60's are unheard of. When I went online for a mini-truck the closest place was Nebraska! (Can't hardly believe that but that was what was offered on salvage that day)

I am not wanting to market or fabricate this set up but thought if it was a marketable/economical power steering set up then some of you guys who are more experienced in this might take it up.

Evidently it wasn't that great of an idea as I got no responses back on the thread. Quite a few views but no responses.

However, the thing drives like a dream eliminating all linkage sway. Have yet to have time to test it off road but can't imagine that it would not perform wellI've seen alot of people viewed this but I was really hoping some of the power steering experts out there were going to punch holes in the conversion to tell me some of the cons so I don't have to find them out myself on the trail.

If there is something that I am overlooking that would make this conversion deficient I would like to know. My biggest fear right now is the cutting of the shock mount. It is cast iron and I will have to weld a triangular plate to have the loads transferred back to the frame.
It looks ok to me. If I see any drawbacks it's cutting the bib and now your bib can't fold down to service the radiator and front of the engine, but the winch probably limited that feature as well.

You can get any box you want as a rebuild from Napa Auto Parts. A good 4-turn Saginaw box is about $150 with an exchange that you can find anywhere.
Steering Radius and does it Rub?

That's something I was nervous about and was real hard to determine exactly where it was going to land prior to getting everything mounted up.

It does not rub here are two pictures. Approximately 1" clearance.

HOWEVER, I was only able to keep one of the stabilizers and it's U bolts hit the front differential when I make a right turn. Meaning it limits the range of turn vs. the steering stops. I believe when I go back and put a new stabilizer on and fix the attachment it will be close.....very close! The other option was to mount it closer to the bumper further away from the bib however I had a winch mounting plate on there that is welded to the frame. (It seemed like a good idea when I welded it there! Not so good of an idea now though!)

The bib is able to fold forward as there is enough wobble to overcome the box. You can't take it all the way down but enough to get to the bolts. I was used to this as the winch is kind of in the way to begin with.
Turning radius2.jpg
Turning radius.jpg
How many turns from lock-to-lock?

Thanks for the photos and diagrams. I'm a regular minitruck PS fan (using a solid axle box), but I appreciate someone using an IFS box.

Users who are viewing this thread

Top Bottom