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Saginaw Conversion

Posted in How To on March 1, 1999 Comment (0)
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Saginaw Conversion
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A steering conversion isn’t a bolt-on, even though the Advance Adapters kit makes it much easier on 1946-1969 Jeeps. You will need a MIG welder and an electric grinder in addition to basic handtools. A steering conversion isn’t a bolt-on, even though the Advance Adapters kit makes it much easier on 1946-1969 Jeeps. You will need a MIG welder and an electric grinder in addition to basic handtools.
You have several choices in steering boxes, and the first is whether you want power or not. If you’re modifying the Jeep enough to justify a steering conversion, you’ll want power steering. If you can get a Saginaw box from a Jeep, it will bolt up easily and won’t require a special pitman arm. The most common source for suitable Saginaw boxes, however, is GM cars. The one you want will have an input shaft with an 0.80-inch-diameter input shaft (most common on 1960s and early-1970s cars). You will also want a power-steering box with four attaching bolts, not three, for strength. You have several choices in steering boxes, and the first is whether you want power or not. If you’re modifying the Jeep enough to justify a steering conversion, you’ll want power steering. If you can get a Saginaw box from a Jeep, it will bolt up easily and won’t require a special pitman arm. The most common source for suitable Saginaw boxes, however, is GM cars. The one you want will have an input shaft with an 0.80-inch-diameter input shaft (most common on 1960s and early-1970s cars). You will also want a power-steering box with four attaching bolts, not three, for strength.
The Jeep used for this article had a steering system worse than what it left the factory with: a butch-and-hack rack-and-pinion conversion. This created several problems beyond what you&#8217re likely to encounter, so we won&#8217t detail the disassembly. The Jeep used for this article had a steering system worse than what it left the factory with: a butch-and-hack rack-and-pinion conversion. This created several problems beyond what you’re likely to encounter, so we won’t detail the disassembly.
The vehicle had also suffered a mid-1970s, non-tilt Oldsmobile column transplant, complete with your father’s steering wheel. That just had to go. While many would opt for a tilt column, the owner of this Jeep wanted to retain a 1940s look so a used, early dispatcher Jeep (DJ) column was purchased from Tri-County Gear. Tri-County also sells used tilt columns. The vehicle had also suffered a mid-1970s, non-tilt Oldsmobile column transplant, complete with your father’s steering wheel. That just had to go. While many would opt for a tilt column, the owner of this Jeep wanted to retain a 1940s look so a used, early dispatcher Jeep (DJ) column was purchased from Tri-County Gear. Tri-County also sells used tilt columns.
The DJ column is about the right length, already has a lower bearing, and has a splined output that can be adapted to Advance&#8217s intermediate shaft with a universal joint. Because it was used, it was rebuilt with a new nut, upper bearing, and shim plates from Crown Automotive. We also replaced the cracked DJ wheel with a new CJ-2A steering wheel from Crown. The DJ column is about the right length, already has a lower bearing, and has a splined output that can be adapted to Advance’s intermediate shaft with a universal joint. Because it was used, it was rebuilt with a new nut, upper bearing, and shim plates from Crown Automotive. We also replaced the cracked DJ wheel with a new CJ-2A steering wheel from Crown.
This job will be much easier if you remove the driver-side fender and grille. You&#8217ll need to bolt these back on before you weld everything in place to make sure there is adequate clearance, but having them out of the way for now will help. This job will be much easier if you remove the driver-side fender and grille. You’ll need to bolt these back on before you weld everything in place to make sure there is adequate clearance, but having them out of the way for now will help.
Unbolt all of the old steering system, including the steering box and the column. Inspect the framerails--there will be considerably more force exerted on the driver-side rail with the steering box mounted in front, so cracks in the frame need to be repaired prior to the swap. A common place for cracks is just ahead of the upper shock mounts. Unbolt all of the old steering system, including the steering box and the column. Inspect the framerails--there will be considerably more force exerted on the driver-side rail with the steering box mounted in front, so cracks in the frame need to be repaired prior to the swap. A common place for cracks is just ahead of the upper shock mounts.
With the frame repaired as necessary and all of the old steering components removed, you can begin assembling the new steering system. Advance Adapters includes a new tie rod, one tie-rod end, a drag link, and clamps to keep everything in place. You can use your existing tie-rod ends or order new ones. The tie rod and drag link have left- and right-hand threads, so you can make alignment adjustments once the conversion is complete. With the frame repaired as necessary and all of the old steering components removed, you can begin assembling the new steering system. Advance Adapters includes a new tie rod, one tie-rod end, a drag link, and clamps to keep everything in place. You can use your existing tie-rod ends or order new ones. The tie rod and drag link have left- and right-hand threads, so you can make alignment adjustments once the conversion is complete.
After the tie rod and drag link are attached to the Jeep, bolt the adapter plate onto the Saginaw steering box. If you&#8217re using a manual box, you will need to drill the box mounting holes so that the 7/16-inch socket-head bolts will clear. Use the high-collar lock washers provided. After the tie rod and drag link are attached to the Jeep, bolt the adapter plate onto the Saginaw steering box. If you’re using a manual box, you will need to drill the box mounting holes so that the 7/16-inch socket-head bolts will clear. Use the high-collar lock washers provided.
The tab on the adapter rests on top of the frame and acts as the vertical locator. In most cases, a power-steering box will need to be all the way forward, against the back of the front bumper. This vehicle has custom framerails now, so the box is positioned so that the drag link is parallel to the tie rod when the pitman arm is in the middle of its travel. Clamp the box in place and check its position. Then weld the adapter to the framerail. The tab on the adapter rests on top of the frame and acts as the vertical locator. In most cases, a power-steering box will need to be all the way forward, against the back of the front bumper. This vehicle has custom framerails now, so the box is positioned so that the drag link is parallel to the tie rod when the pitman arm is in the middle of its travel. Clamp the box in place and check its position. Then weld the adapter to the framerail.
Next you will need to work on your steering column. If you&#8217re using a stock column, cut the shaft and remove the stock steering box. The end of the shaft must be machined to 7/8-inch diameter to fit the Flaming River universal joint provided, and installing the brass bushing in the bottom finishes the column. This Jeep was fitted with a DJ column that didn&#8217t need cutting and has a splined shaft that will require a different universal joint. Advanced Adapters also provides the firewall plate, which must be welded into place to secure the lower portion of the steering column. Next you will need to work on your steering column. If you’re using a stock column, cut the shaft and remove the stock steering box. The end of the shaft must be machined to 7/8-inch diameter to fit the Flaming River universal joint provided, and installing the brass bushing in the bottom finishes the column. This Jeep was fitted with a DJ column that didn’t need cutting and has a splined shaft that will require a different universal joint. Advanced Adapters also provides the firewall plate, which must be welded into place to secure the lower portion of the steering column.
Advance Adapters includes a 36-spline spud shaft to connect its intermediate shaft to your steering box. If your steering box does not have a 36-spline input shaft, you&#8217ll need a different spud shaft or box. The intermediate shaft is 3/4-inch, double-D with a special 2-inch slip-yoke installed under the plastic boot. Advance Adapters includes a 36-spline spud shaft to connect its intermediate shaft to your steering box. If your steering box does not have a 36-spline input shaft, you’ll need a different spud shaft or box. The intermediate shaft is 3/4-inch, double-D with a special 2-inch slip-yoke installed under the plastic boot.
With the box properly mounted, route the intermediate shaft to the end of the steering column. Install the universal joint on the end of the column and mark the intermediate shaft so that you can cut it to the proper length. Routing can be a disaster: You need to ensure that there is enough clearance for the engine, the radiator, the exhaust system, and the brake and fuel lines. You must also keep the angles at the universal joints under 15 degrees so they can operate. Once everything clears and is assembled, use Lock-Tite on all of the set screws and have the Jeep aligned. With the box properly mounted, route the intermediate shaft to the end of the steering column. Install the universal joint on the end of the column and mark the intermediate shaft so that you can cut it to the proper length. Routing can be a disaster: You need to ensure that there is enough clearance for the engine, the radiator, the exhaust system, and the brake and fuel lines. You must also keep the angles at the universal joints under 15 degrees so they can operate. Once everything clears and is assembled, use Lock-Tite on all of the set screws and have the Jeep aligned.

As cool as old Jeeps are to build, there are several mechanical systems that just cannot be overlooked. Well, you can try, but sooner or later the weak parts will end up on the ground and you’ll be stuck trying to limp home. One of the worst items on pre-’70 Jeeps is the steering system. The original mounts the steering box behind the front axle and connects to the front wheels through four relay rods and two idler arms. Even if you’re not building an extreme Jeep, all of these connections make for plenty of slop in the steering, and if you’re going nuts with larger tires and a lift, then you have to ditch this system.

Advance Adapters offers a conversion kit for '46-'69 Jeep vehicles that gives you all the pieces you'll need to adapt either a manual or power Saginaw steering box. The kit includes a new tie rod and one tie-rod end, a drag link, a steering-box mounting plate, frame enclosures to box the framerails, a lower steering column bearing, an intermediate shaft, a spud shaft to connect the box to the new intermediate shaft, a Flaming River universal joint, a very helpful conversion booklet, and the necessary nuts, bolts, and clamps. The swap requires cutting and welding so it more or less falls under fabrication work, but the Advance kit gives you all the pieces you need except for the steering box, the pump, the pitman arm, and the steering hoses.

Because you are revising the steering system, you must take extreme care to follow all of the instructions and ensure that everything is performed correctly. Close enough doesn't cut it on steering.

Sources

Tri-County Gear
909-623-3373
http://www.tricountygear.com
Advance Adapters Inc.
800-350-2223
www.advanceadapters.com
Crown Automotive Sales Co. Inc. North Prembroke, MA

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