Can any body that has done IH Scout psteering conversion on their rig give me some help? Like how does it work? Where can I find a box,preferebly rebuilt (around Charlotte,NC) ? I have read the thread and I have more questions.
IH Scout PS conversion/76 FJ40 (1 Viewer)
- Thread starter GREEKMEAT
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jfz80
Cruisin’
I did the scout conversion on my 55. It works extremely well and turns big tires very easy. Maybe even too easy as it seems awfully light in the steering. (but i am used to 90's era vehicles)
Get the right pitman arm.... sorry i dont recall which one it is off hand.
Definately take the time to sleeve the bolts as well as add the reinforcement plate to the frame. Diagonal bracing from the frame to the crossmember stiffens it up even more. The return line pressure on the scout box is extremely strong and will cause flexing of the frame if not reinforced. I pulled my box at a yard and did not rebuild it...... DONT DO THAT. too much trouble not to just rebuild it first. Also you could buy a reman unit at NAPA I think it was around 170 with a core.
post up on ONSC (olde north state cruisers) forum for some local suggestions and or help. We have a couple members in Indian Trail actually.
Get the right pitman arm.... sorry i dont recall which one it is off hand.
Definately take the time to sleeve the bolts as well as add the reinforcement plate to the frame. Diagonal bracing from the frame to the crossmember stiffens it up even more. The return line pressure on the scout box is extremely strong and will cause flexing of the frame if not reinforced. I pulled my box at a yard and did not rebuild it...... DONT DO THAT. too much trouble not to just rebuild it first. Also you could buy a reman unit at NAPA I think it was around 170 with a core.
post up on ONSC (olde north state cruisers) forum for some local suggestions and or help. We have a couple members in Indian Trail actually.
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LC_Hamma
The Anti-Leafer
There are 4 different Scout Saginaw conversions in the Tech Links section, FYI. On the pitman arm, I used a 3" drop from a YJ. I wouldn't use the Scout pitman as it's about 8" long & no drop. You may be able to find a core thru CarPart.com - Quality Automotive Parts at Wholesale Prices or I have an extra one. I'd add an inner frame brace to the crossmember.
I have it some where in my build thread if you wish to view it (search under my name). Some of the issues I ran into is that I whipped up a shackle reversal that utilized my rear mount on the front (low profile style) which in turn made the spring very close to my 1" drop pitman arm. I will not be suprised if I dont end up needing a flat one to barely miss the frame and barely miss the springs during flex. I also have a high steer kit sitting here that I am crossing my fingers that after the cut and turn my tie rod will clear above the spring.... I am not sure it will. I might end up having to go with Lukes. With all that said it would be fine with the factory arms - EVERYTHING I HAVE MENTIONED WAS BASED OFF OF A SPRING OVER AXLE vehicle it would be totally different for a sua.
rsbcruiser
SILVER Star
Just can't let this one go. It is the transfer of force from the steering that causes the frame flex. With the old system these forces are distributed nicely between the frame pieces. Basically, the force is in plane with the frame (a gross simplification). When you change to a Scout system you have accomplished two things. One, All of the load is now transfered to the frame at one point and most of that load is now out of plane. Two, you have increased the amount of force possible.
jfz80
Cruisin’
fair enough.... perhaps thats a poor simplified explanation, I simply meant that the 500 + psi behind the pushing doesnt help any.
its got to be true, i read it here on mud
Im obviously no welder or physics expert, but I agree with your further explanation.
from the tech links... and yes it all depends on the length of the pitman arm
Power Steering...
Scout Steering box:
I ran a test with the Scout power steering box. I tested the box from 0 to 800 psi at an incriment of 200 psi. Here is some of my data and calculations.
Oil Pressure (PSI)
input torque, no pressure
200
400
600
800
Torque output (ft*lbs)
134
218
312
412
552
Force in drag link (lbs)
173.8
282.8
404.8
534.5
716.1
The torque output in this chart only represents the added torque of the power assist. To find the actual maximum torque output, the driver input also needs to be added. The Scout box also has a ratio of 20:1. The box is a Saginaw box that uses a very efficient worm and roller gear. I have heard that the gear is about 90% efficient. Stock it has a pitman arm length of 9.25" (I might try to swap mine with a shorter one later).
Torque in steering wheel=(.75')(50 lbs.**)=37.5 ft*lbs
**25 lbs per hand
Torque out of gear box=(37.5 ft*lbs)(20/1 gear ratio)(90% efficiency)=675 ft*lbs
Force in drag link of driver=(675 ft*lbs)/(9.25"/12")=876 lbs
Force in drag link of assist=(716.1 lbs)-(173.8 lbs)=542.3 lbs
Force in drag link total=(876 lbs)+(542.3 lbs)=1418 lbs
Bottom line, the Scout box puts out 515 lbs. more force into the drag link with a longer pitman arm than the Cruiser. It has a more efficient type of gear, gets rid of two extra tie-rod ends, and turns quicker than a stock Cruiser. Just be careful not to break things with the extra power.
its got to be true, i read it here on mud
Im obviously no welder or physics expert, but I agree with your further explanation.
from the tech links... and yes it all depends on the length of the pitman arm
Power Steering...
Scout Steering box:
I ran a test with the Scout power steering box. I tested the box from 0 to 800 psi at an incriment of 200 psi. Here is some of my data and calculations.
Oil Pressure (PSI)
input torque, no pressure
200
400
600
800
Torque output (ft*lbs)
134
218
312
412
552
Force in drag link (lbs)
173.8
282.8
404.8
534.5
716.1
The torque output in this chart only represents the added torque of the power assist. To find the actual maximum torque output, the driver input also needs to be added. The Scout box also has a ratio of 20:1. The box is a Saginaw box that uses a very efficient worm and roller gear. I have heard that the gear is about 90% efficient. Stock it has a pitman arm length of 9.25" (I might try to swap mine with a shorter one later).
Torque in steering wheel=(.75')(50 lbs.**)=37.5 ft*lbs
**25 lbs per hand
Torque out of gear box=(37.5 ft*lbs)(20/1 gear ratio)(90% efficiency)=675 ft*lbs
Force in drag link of driver=(675 ft*lbs)/(9.25"/12")=876 lbs
Force in drag link of assist=(716.1 lbs)-(173.8 lbs)=542.3 lbs
Force in drag link total=(876 lbs)+(542.3 lbs)=1418 lbs
Bottom line, the Scout box puts out 515 lbs. more force into the drag link with a longer pitman arm than the Cruiser. It has a more efficient type of gear, gets rid of two extra tie-rod ends, and turns quicker than a stock Cruiser. Just be careful not to break things with the extra power.
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- Thread starter
- #7
scout/conversion
Thanx for info fellas. Couple more questions though. At NAPA they listed 4 different ps boxes, as follows:
1971-74 with 13/16ths input shaft = in-stock item
75 ONLY XLC ?
1976-79 3/4" input shaft =special order
1976-79 13/16ths input =Special order
Which one should I get ? I am going to probably get the in stock one if nobody knows.
2nd Question , How different is the steering on a 55 than a 40 ? It seem most of the conversions are on a 55.
3rd question, how much radiator brace trimming will be involved with the placement of this ps box, if any ?
Thanx for info fellas. Couple more questions though. At NAPA they listed 4 different ps boxes, as follows:
1971-74 with 13/16ths input shaft = in-stock item
75 ONLY XLC ?
1976-79 3/4" input shaft =special order
1976-79 13/16ths input =Special order
Which one should I get ? I am going to probably get the in stock one if nobody knows.
2nd Question , How different is the steering on a 55 than a 40 ? It seem most of the conversions are on a 55.
3rd question, how much radiator brace trimming will be involved with the placement of this ps box, if any ?
Thanx for info fellas. Couple more questions though. At NAPA they listed 4 different ps boxes, as follows:
1971-74 with 13/16ths input shaft = in-stock item
75 ONLY XLC ?
1976-79 3/4" input shaft =special order
1976-79 13/16ths input =Special order
Which one should I get ? I am going to probably get the in stock one if nobody knows.
2nd Question , How different is the steering on a 55 than a 40 ? It seem most of the conversions are on a 55.
3rd question, how much radiator brace trimming will be involved with the placement of this ps box, if any ?
Don't know what the difference is between the 71-74 and the 76-79 but mine is 13/16ths shaft and a 3 bolt mount (year uknown). As to your last question, if you use some 3/4 by 4" stock, drill and tap into the 3/4 for mounting the box and weld that to the frame you will not need to do any trimming of the rad brace as the 3/4 lets the box clear the brace. My Scout steering is not completed yet, it's ready to bolt on but I need to finish building the 60 axle and do the spring outboarding.
Don
pb4ugo
SILVER Star
My box has the 13/16" input w/3 mounting bolts. I dont' know what yr it came from other than it had disc brakes. I did the 3/4" approx scab plate and sleeved the frame along w/the ford shock tower. It cleared the rad support but was close so I altered the mounting holes for the rad support and moved it over approx 1/4-3/8" I just wanted a tick more room for clearance. I used a 4" drop pitman arm for a wagoneer B/C of my current frt end and eventual upgrade to high steer w/a LC frt end. I like it better than my old sag conversion out front. Good Luck
I used the box out of a '77 Scout ( 13/16'sx36 ), Ford tower cut off to match pass/side, bearing for colume , along with ujoint/yokes from Kurt at Cruiser Outfitters, made my own draglink using Toy/Jeep sections cut to length, then sleeved. Grab a steering shaft out of a Toy mini/FourRunner, will be a tad longer than you need, but is made to coliapse in an accident. Mark on the side of the frame where the stock draglink rod end sits, and set your box in place where it's simular, this will keep everything in stock like placement= no bump steer. HTH, Al
Great info, what pitmam arm did you use? Got any pics of how it sits in relationship to the frame and springs?
- Thread starter
- #13
Well, the box i picked up today is the wrong one, which was a 71-74 model box.
what made it the wrong one?
- Thread starter
- #15
It had a 4 bolt mount and was cocked to the wrong direction, anyway I sent it back and will order the later year model which I think was 76-79.
