OBS/TTB conversion to 2011+ Superduty steering box

CowBro

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After being away from the forums for what seems like forever, it is hard to get back into it, but I want to do my part to support this place, and hopefully help bring back the feel of the old days. This is my latest upgrade to my 93 Ranger, but the tech should translate over to any TTB Ranger, 80-96 F-150/250/350 that is running the stock steering box. My truck is running a modified D44 TTB up front with stock style steering, coil springs, 2.5" resi shocks and 2x2 air bumps. The rear end is a set of F31 Deavers and 2.5 SAW's. 4.0, 5speed, 5:1 Atlas, ARB's front and rear, 4.88s, chromo shafts front and rear on 37s. The main use for the truck is to drive 2.5 hours to the Rubicon and wheel the trail 5-6 times per year.

3 or 4 years ago i did the proquipped Saginaw Pump conversion with a PSC underdrive pulley and it made a big difference in power assist for the steering with 37s. Then this past winter i swapped out the slightly leaky power steering box for a rebuilt redhead box. All was good until last month at Slickrock trail when the o-ring under the top cap blew out in the middle of the trail. Luckily there was a group of Full size broncos behind us, and one of them had a spare box i was able to borrow to get me home.

This was the final push i needed to dive into the superduty steering box upgrade. Since 1980 all ford truck steering boxes have used the same 3 bolt pattern. All of the boxes from 1980-1996 were exactly the same, which makes it really nice for interchangeable parts. When the superduty trucks came out in 99, they stared upgrading the steering boxes. 99-04 got a 4 bolt cap, slightly larger sector shaft (36 spline with 4 blanks) but kept the small 7/16" mounting bolts. 05-08 got an even larger sector shaft (33 spline with 3 blanks), and upgraded to 14mm mointing bolts. 08-10 got some revisions and then in 2011 the boxes got much larger, using the same 33spline sector shaft from 05+ and upgrading to 16mm mounting bolts.

I've seen lots of stuff online where someone has swappped an 04 box to an OBS, or 2010 to an 04, or 2011 to an 08, but i haven't found anyone that has done a 2011+ to an OBS/Ranger frame. Theoretically, you should just have to drill out the frame to 16mm(5/8") and it will bolt in with a new pitman arm, hoses and steering shaft joint.

I picked up a Blue-Top 2011 box, here it is next to the 80-96 steering box. It is significantly bigger. Most importantly, the piston size inside is larger which should provide more assist to turn the tires.
Box Comparison1.jpg

Box Comparison2.jpg



Here is the comparison between the 7/16" bolts and the 16mm bolts. I couldn't use stock 2011 bolts because the ranger frame is thinner and they would have been too long. Stock steering box bolts are listed as 130mm, but i think they measure the overall length, including the head. I picked these up from McMaster :16mm x 2.0Pitch x 100mm long.

Bolt comparison.jpg
 
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First step after pulling the old box was to drill out the frame. I tried the old 5/8" drill bit and the first ~1/4" went well, but after that, i could tell that whatever ford put inside the frame as a sleeve to prevent crushing the frame with the steering box bolts was not going to let me drill them out like i needed to. The "sleeve" was offcenter in the holes, or only around part of the holes. The easiest solution i could come up with was to window the outside of the frame and rebuilt it with proper sleeves. If you ever wondered what the inside of this part of the frame looks like, here you go:

Frame cut.jpg

Frame open.jpg


The sleeve is held in with a little tab that pokes through the back side of the frame and is welded on the outside. I was able to hit it with a flap wheel and it popped right out.
sleeve.jpg

From there i cut 3ea new sleeves from 1"x.120" DOM at 2-9/16" to match the width of the factory sleeve, bolted the box up to hold it all together and then welded it back together. The sleeves are welded to the outer section of frame before bolting it all together.
bolted in.jpg

This is where she currently sits. Next step is going to be to grind the welds smooth and make a nice overlay plate to reinforce the outside of the frame after cutting/welding.
welded.jpg
 
Yeah this is a pretty interesting swap. For one, i had no idea thats how they made the sleeves for the bolts, but it makes sense from a manufacturing standpoint.

These boxes have a bigger sector shaft (36 spline as opposed to the older 32 spline boxes) which is pretty nice if youre breaking sector shafts the OBS boxes. BroncoJoe96 probably needs this upgrade.

Im curious if the bigger piston actually makes a difference in how much torque the steering box has. Can confirm, theres more than one way to tap an OBS box for hydro-assist, and it makes a difference in how it performs.
 
rattle_snake said:
Sooo, how much more better assist is the SD box over the 80-95? Is it a viable option instead of a ram assist for 40s?
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Unfortunately, i am not going to be able to give you a good quantitative value. i would love to pull both boxes apart and measure the diameter of the pistons, but that isn't really in the cards for me. The gear ratios of the boxes are the same, so the advantage comes from the fact that you have ~1600psi pushing on a piston that is ~10%-20% more surface area inside the box.

I have no plans to put 40's on my truck with the half ton axles and 150hp, but that is my hope that it provides similar steering power to hydro assist without loosing the ability to make quick steering inputs on the highway. Also, with the TTB and stock style steering my only option for hydro assist is to land the ram on the pitman arm which isn't ideal.
 
One more tid-bit. The 2011+ box is BIG, much larger than the original one. Just getting it into position was tough, it would have been much easier to drain the cooling system and remove the lower radiator hose, but i was able to squeeze it past, once in position, the radiator hose helped hold the box in place, which was handy. The only physical interference was between the steering box and the frame at the front edge of the engine cross member. There is a bolt on the box that rubbed on the frame, i needed about 1/2" more clearance there, so i took the grinder to the frame on the inside and ground a little off of the bolt. Once i did that, the box bolted right in. This was hard to take pictures of inside the frame, but if you tackle this yourself, be aware that you'll need to do a little trimming in here.

Bolt grind.jpg

bolt clearance.jpg
 
With beams you should be single swinger steering. That gives a great place to mount the ram.
 
bdkw1 said:
With beams you should be single swinger steering. That gives a great place to mount the ram.
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This truck has been through a handful of re-builds throughout the years, previously it was my "prerunner" with fiberglass fenders, etc and had a swing set steering and it worked great. When this truck became my dedicated trail rig I switched back to the stock style steering, it works really well and is super easy to maintain, it is f250 ambulance inner tie rods and 7/8 heim outers. The swingset steering had 6+ heims, plus the pivots for the swinger, too many potential failure/wear points.

My beam pivots are only ~2" of drop, and line up perfectly with a drop pitman arm, It obviously is going to have some bump steer at the extremes of the travel range, but it isn't noticeable, nor does it hold the truck back.
 
The correct pitman arm just showed up in the mail, so I can give you the full comparison. Note that the early 99 Superduty trucks used the old 32 spline sector shaft and thus, their pitman should be interchangeable with the 80-96 trucks.
Pitman comparison.jpg

I was getting some conflicting information on the internet where both the 99-04 and 05+ were referred to as "36 spline" so i was hoping to be able to use the 99-04 pitman for my truck and everything would bolt up, that is not the case, so I'm going to use the 05+ and i have a TRE spacer coming in the mail so I can use my current steering.

TRE spacer from E-Bay

The 05+ pitman nut is a 30mmx1.5pitch that uses a 46mm socket, i'm still waiting on the nut to come in the mail. The 1980-96 nut is a 7/8" thread that uses a 1-5/16" socket. I do not know what the nut for the 99-04 is, if anyone knows and wants to throw that info in here, feel free.
 
Love the cut-weld-grind adapting moar beef.

I would’ve cut those stupid dumbo ears off the control valve housing though!
 
WiscoF100 said:
Love the cut-weld-grind adapting moar beef.

I would’ve cut those stupid dumbo ears off the control valve housing though!
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I thought about it, but they are not in the way at all, and if i modified the box, then i wouldn't be able to use it as a core if i ever need to have it rebuilt. One of my goals is to use an off-the-shelf box, off the shelf pitman arm, etc, to keep maintenance simple.
 
arse_sidewards said:
I assure you the parts store doesn't care. :laughing:
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Yeah, but Redhead/Bluetop do. Honestly though, if i have any trouble with this box, I'll probably go find a low-mileage one out of a brand new superduty. I think that would probably be the best bet. But really, the awkward wings are not in the way of anything, so there is no need to waste time cutting them off.
 
Well, The last few parts rolled in on Friday and I got everything hooked up over the weekend.
test fit.jpg

The adapter sleeve to fit the smaller TRE in the 05+ pitman arm worked perfect. $50 for 2ea, so i have a spare if the first gets messed up or stuck to a TRE.
TRE adapter.jpg

I cut off the factory rubber joint at the steering box side of the steering shaft, shortened up the remaining section of the shaft and fitted it with a borgeson u-joint designed specifically for the "Ford Truck V" shaped shaft. Note that there are at least 2ea of the "V" Shaped steering box shafts (Mustang and Truck), they are both the same OD, but the chamfers are different and not interchangeable. Most companies only refer to the Ford V or Ford Triangle. Borgeson is the only one that had a separate "Truck V".

Part number: Borgeson part 034956
Steering shaft.jpg


I already had a -6AN high pressure hose that i was able to re-use with a simple 18mm 0-ring x -6AN adapter at the box, the return got a similar adapter to -6 and a pushlock hose return line to the pump. I may add a cooler this winter. I've never monitored the power steering temps, so i may do that on the next few trips.
Hoses.jpg


The power assist is more than i had hoped for. I haven't had it off road yet, but at idle on pavement it is a super easy one finger steering, very similar to what you would expect with hydro assist. I still need to clean up the frame and add a reinforcement over where i cut the frame and tighten everything down. But overall super happy with it and i would recommend to anyone with 1980-1997 ford truck.

Phil
 
WiscoF100 said:
:smokin:

I’m not familiar with a “V” shaft. Is that the designation or shape?
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It is a bad description of the shape. Lol. The "mustang V" started on the SN95 mustangs i believe. the ford truck V started in late 08 i believe. The difference is the angle between the two flat sections. The Truck V, the flats are more parallel to each other. This is a picture of the mustang V. If i pull the box again, i'll get a good picture.

Ford V.jpg
 
Update. I've got some miles on it so far. Everything is pretty much working as expected. The holidays and a vacation to Florida has prevented any actual offroad testing, but it is great on the street and around town. At idle and low speeds the steering power is insane. The steering definitely feels different (floaty?) at 45+mph, the best way i can describe it is that it feels like i went from 6* of caster to 2*. It still returns to center, but it will wander much easier if little corrections aren't constantly made. Unfortunately i don't have an easy way to dial in more caster, so I'll be living with it for now and just getting used to it, I've had this truck for 22 years, so I am probably more sensitive to little changes than others might be.

I have contemplated adding adding a steering stabilizer to help out on the highway... not sure if it will help or provide the desired effect.
 
CowBro said:
I have contemplated adding adding a steering stabilizer to help out on the highway... not sure if it will help or provide the desired effect.
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Bro I'd say no. A damper's purpose is to stabilizes steer angle when forces are applied to the tires. I'd say you feel over-assist, but as you mention it is all relative. You can always add caster with grinder and welder.
 
CowBro said:
Update. I've got some miles on it so far. Everything is pretty much working as expected. The holidays and a vacation to Florida has prevented any actual offroad testing, but it is great on the street and around town. At idle and low speeds the steering power is insane. The steering definitely feels different (floaty?) at 45+mph, the best way i can describe it is that it feels like i went from 6* of caster to 2*. It still returns to center, but it will wander much easier if little corrections aren't constantly made. Unfortunately i don't have an easy way to dial in more caster, so I'll be living with it for now and just getting used to it, I've had this truck for 22 years, so I am probably more sensitive to little changes than others might be.

I have contemplated adding adding a steering stabilizer to help out on the highway... not sure if it will help or provide the desired effect.
Click to expand...

Since you're the new super duty steering box pro, I have a 2008 f350 4wd chassis that had a fire, and probably needs a new steering box, but it looks like 08 was a split year, I didn't know why, but reading your posts, I'm guessing it's because of the intermediate shaft changes...

So I'm going to need a box and a shaft for my project, I'll make sure to get a matched pair

Anyways, in your knowledge, can I bolt any box from 2005 to 14ish to my frame and it fit correctly? Pittman arm differences?



Great tech, thanks for posting it :smokin:
 
Projectjunkie said:
Since you're the new super duty steering box pro, I have a 2008 f350 4wd chassis that had a fire, and probably needs a new steering box, but it looks like 08 was a split year, I didn't know why, but reading your posts, I'm guessing it's because of the intermediate shaft changes...

So I'm going to need a box and a shaft for my project, I'll make sure to get a matched pair

Anyways, in your knowledge, can I bolt any box from 2005 to 14ish to my frame and it fit correctly? Pittman arm differences?



Great tech, thanks for posting it :smokin:
Click to expand...
Yes, 2008 was a split year, AFAIK this was the year that they changed from the splined input shaft(early2008) to the "Ford V" (late 2008)input shaft.

Any box from 2005+ should work, as long as you have the corresponding intermediate shaft. However, if you need a new box, you might as well get a 2011+ box because it is bigger and better, you would just need to drill out the frame to switch from 14mm to 16mm mounting bolts, I would hope that you wouldn't have to cut open the frame like i did going from 11mm to 16mm bolts. Used 2011+ boxes can be found on ebay for ~$300.

2005+ all use the same pitman arms, no difference there.
 
CowBro said:
Yes, 2008 was a split year, AFAIK this was the year that they changed from the splined input shaft(early2008) to the "Ford V" (late 2008)input shaft.

Any box from 2005+ should work, as long as you have the corresponding intermediate shaft. However, if you need a new box, you might as well get a 2011+ box because it is bigger and better, you would just need to drill out the frame to switch from 14mm to 16mm mounting bolts, I would hope that you wouldn't have to cut open the frame like i did going from 11mm to 16mm bolts. Used 2011+ boxes can be found on ebay for ~$300.

2005+ all use the same pitman arms, no difference there.
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Sweet, looking at junkyard interchange now

11-16 is the same

But, there's a 6.2 gas option and a 6.7 diesel option

Any idea what the difference is?
 
Projectjunkie said:
Sweet, looking at junkyard interchange now

11-16 is the same

But, there's a 6.2 gas option and a 6.7 diesel option

Any idea what the difference is?
Click to expand...
AFAIK, the steering/steering boxes are all the same between gas and diesel.
 
I want to bump this back up with an update. After 2 months of tootling around town and one longer highway trip / mild offroading I can say that i am super happy with the new steering box. My initial thought that it made the steering more twitchy was becuase the Superduty drop pitman arm had ~1/2" more drop that my old arm, and that combined with the stock style TTB steering gave me just a hint of toe-out. I adjusted the toe in a little and it all went back to normal, i guess i should have assumed Hands off the wheel, cruising at 70mph all day.
 
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