71 highboy conversion to power steering

[mlheppl]

I know that there is a great article linked to on the home page chronicling the use of an early 70's 2wd steering sector. I've only been on Fordification a few months, and have already seen several threads asking how do I install XXX steering sector. There are lots of possible combinations of steering sectorsand other ancillary equipment needed to complete these conversions.

I'm utilizing a steering sector out of a 78-79 F250 4X4. I thought I'd take the time to document my conversion. Maybe others can find this info usefull (if only for how not to do things). Let me say right off the bat that is not the only possible way to do this particular conversion. Possibly not even the best way, just how I did it.

My PS conversion actually started back around 1995. The original 360 in my truck was getting pretty tired, so I put a 400 in my truck. The PS pump, brackets, pulleys and hoses were already on the motor, so I left them on. I knew someday I'd swap over to PS. So anyways, that part has been complete for quite a while. Last december I had the opportunity to get a steering sectorw/ pitman arm off of a 78 F250 4X4 for $75. I jumped at it as this is less than core price and a rebuilt one goes for over $300.

Between snow storms the last couple of months I've managed to get some work done. I pulled the hood, front clip and radiator support off of the truck. Once all of that was out of the way I could better see what steps I needed to take to do the swap. The first thing I noticed is that the frame is curled up just in front of the motor mounts. My new steering sector would not clear this extra height.

The frame looks like this:

[mlheppl]

After some deliberation with myself I took a torch and cut the raised section of frame out so that it looked like this:



Being as this would be the last time the inside of the frame was accessible, I applied several coats of primer and later flat black paint. That is the condition that you see in the above picture.

I then purchased a piece of metal 8" long by 6" tall by 3/8" thick. This piece of steel plate cost me $10. I trimmed the piece down to fit the opening and frame contour.

The plate:


fitment:

[mlheppl]

After I had the plate trimmed the way that I wanted it, I tack welded it in place. I put the steering sector in place. I moved it as close to the motor mount as I could. I'm hoping this will allow room for the radiator support and radiator. At this time I'm not sure if it worked as I'm not ready to re-install the radiator support. I'll let you know when we get there.

After setting the steering sector in place, I held it in place with a c clamp. Then I marked where each of the holes needed to be drilled. I removed the sector and ground the welds and removed the plate. I then center punched each hole and drilled the holes out to 5/8". I utilized my bench top drill press for this task. I'd like to note that I started with a 3/8" bit, then stepped up to a 1/2" bit and then made the final drill with a 5/8" bit (which I had to buy). I also purchased four 9/16" X 3 1/2" grade 8 bolts for mounting the sector. Cost of the bit and the 4 mounting bolts was $33.00

After drilling the mounting holes, I primered and painted the back side of the plate as this would be the last opportunity to do so. When the paint was dry, I final welded the plate in place.





Once the plate was in place, I chucked the 5/8" bit in my drill and using the holes in the plate as a guide, I drilled corresponding holes in the frame of the truck.

[mlheppl]

Once the plate was welded in, I mounted the steering sector. I checked to ensure that the pitman arm did not bind anywhere as the pitman arm sits between the bottom of the frame and above the front spring.



The intermediate steering shaft had to be shortened. I felt I had two options to do this. 1st I could cut the shaft in the middle, shorten it to length then weld it back together with a piece of pipe slid over the weld for strength. Option two was to install a steering u-joint on the bottom end of the shaft. I opted to go with the steering u-joint mainly because it wasn't that expensive and I felt it would be more aesthetically pleasing.

steering u-joint:


I bought the u-joint from speedway motors for $40. It is a forged 3/4" 36 spline X 3/4" round weld on end. I mounted the u-joint onto the steering sector. Then I lined up the intermediate steering shaft and marked where I needed to cut the shaft. Using a sawsall, I cut the intermediate shaft. Then I unbolted the sector, mated the intermediate shaft into the u-joint and remounted the steering sector. After that I made sure that the pitman arm was in the middle of it's stroke. For this box that is 2 revolutions of the sectors input shaft from either end. Next I made sure my steering wheel was centered. Then I welded the intermediate shaft to the steering u-joint. After cleaning up the weld, I primered and painted the weld area to prevent rust.

[mlheppl]

The above post is where I'm at as of today. I still need to purchase a drag link and hook the hoses up from the power steering pump to the steering sector. With any luck, I'll have the drag link in hand for my next set of days off.

[convincor]

The only thing I would have done different there is tube spacers between the frame and your plate to prevent the bolts from crushing the dead space between. You could still add something.

When I did mine 68 years back I got a kit from-
Ibeling Repair & conversions
1101 Ellis st
Applington, Iowa 50604
(319) 347-2491

They have a complete kit to convert the 67-77 HI-Boy's i believe using the 69-79 2wd Bendix box.
I used there kit back when I did my 68 F250 and it was the best thing I ever did to that truck.

[mlheppl]

I used extra large washers like 2" or 2 1/4" diameter on the frame side. Do you think I'll still collapse the frame side in? I doubt that the 3/8" plate is going to collapse. I could still put some spacers in there, I just figured that the large washers would distribute the pressure enough to prevent pinching the frame in.

[Doug Comer]

I agree woth putting the spacers in the frame also. Did it to both the trucks I did. Just my . Nice job by the way

Doug

[convincor]

I used extra large washers like 2" or 2 1/4" diameter on the frame side. Do you think I'll still collapse the frame side in? I doubt that the 3/8" plate is going to collapse. I could still put some spacers in there, I just figured that the large washers would distribute the pressure enough to prevent pinching the frame in.

Yes, these a lot more pressure there than you'd think.

[averagef250]

#1 you absolutely need spacers inside the frame. Please don't drive that on the road without spacers.

#2 you may need to cut all that out, notch your front crossmember and move it all back about 1.5" to clear the radiator. After that you will still need to cut your fan shroud up to clear the box.

The radiator is the tightest thing to the steering box, the biggest obstacle to overcome when grafting a different box to the frame.

[mlheppl]

I placed (just set it in place not bolted down)the radiator support on the front of the truck today. It looks to me like cutting a small notch out below the radiator mounting bolt will give me the room needed to mount the support. I've got half a bolt hole alignment/misalignment between the support mounting hole and the frame mounting hole on the drivers side.

I don't have a fan shroud mounted to the radiator. I've got a donor truck that has a shroud and was considering installing it, but have never had cooling problems so IMO not a must do, but I feel it would give a cleaner look to the engine compartment if it was there.

What material do you guys suggest for the spacers? The two materials that came to mind was using 3/4" black iron pipe, or a 3/4" threaded pipe coupler. I'm using 9/16" bolts for mounting the sector.

[convincor]

the black pipe will work. try'n cut'm tight.

[mlheppl]

I was thinking the pipe would be easier to cut in my chop saw. Cut em a little long and grind to fit.

Was thinking a bit ago about the radiator support. My original support has some rust out. My donor truck has a good support (2wd donor truck). I was going to remove the brackets off of my original support and weld them onto my replacement. What if I were to offset the brackets like 3/8" to the passenger side? This would allow the necessary clearance on the steering sector. It would mean that I wouldn't be able to use the fan shroud , but would make it so that I wouldn't have to notch out the mounting brackets on the core support.

What do you think of this idea?

[hazelnut]

if you move the support its going to shift the front of your truck body and your body lines are not going to line up right. you would end up with a big gap between the hood and cowl on the drivers side

[mlheppl]

if you move the support its going to shift the front of your truck body and your body lines are not going to line up right. you would end up with a big gap between the hood and cowl on the drivers side

I wasn't going to shift the whole support over to the passenger side. The highboys have a bracket that the radiator mounts to. When I re-install the brackets onto the donor radiator support, I was thinking of shifting just the mounting brackets. This would offset the radiator to the passenger side just a bit.