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Early Bronco Suspension Refresh

Posted in How To: Suspension Brakes on February 21, 2019
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In the off-road industry, some company names are undeniably linked to the vehicle manufacturer they support. We all know Budweiser makes beer and Coke makes cola. Well, if you know off-road, you know that James Duff and the Ford Bronco are forever twinned. James Duff is a company named after the guy who started when products to support the off-road lifestyle were few. With the introduction of the Ford Bronco in 1966, the vehicle’s off-road potential was quickly realized and Duff was right there fixing the weak points and upgrading what could be made better (he started to sell Bronco parts in 1967). To this day, the name and the company continues to be synonymous with quality parts for the Ford Bronco.

Our 1969 Bronco is many things, but mostly it really is (or was) a neglected magazine project vehicle in need of much love. Over the past two years or so we’ve spent time, sweat, money, and elbow grease trying to bring it back to glory. James Duff has been a part of that plan from the beginning. You see, ’round about the year 2000, a prototype long-arm suspension from James Duff had been installed on it. That suspension has since become one of the iconic part numbers in the company’s catalog. When we decided to revamp this former 4WOR project, we once again reached out to James Duff. The company wanted the prototype parts back for posterity, and we wanted new shocks, springs, and polyurethane components so the old Bronco would ride like new.

Initially our plan was to get the Bronco running and driving quickly, but since we found a little more rust than expected, the project turned into a full teardown and resto-mod, of which we are still in the throes. We have crossed one bridge, which was using the suspension parts from James Duff to revitalize the boing in the Bronco. This, with a little paint and a few more hours of reassembly, should help put the buck back in our Bronco.

Laying out what we got from James Duff shows us the new coils, new long control arms, new head units, bushings, rod ends, a big bag of hardware, and shocks, shocks, shocks, and more shocks.
The years of salty coastal California air had not been friendly to the Bronco, especially the axle C-bushings and shock shafts. Rusty shock shafts would instantly kill the seals and make the old James Duff shocks leak like crazy. The polyurethane was full of cracks and definitely showed its age. Sure, we could just leave it be, but a few bumps off-road would turn this bushing (and many less obvious bushings) to dust.
We started the install by hoisting the Bronco up on our BendPak two-post lift with the front axle on jackstands so we could pull the old radius arms (one side at a time), coil springs, metal bits, and more. We then glass-beaded the factory coil spring retainer parts for paint, and began to assemble the new parts in the kit. These polyurethane bushings isolate the head unit that bolts to the axle from the long blue high-clearance James Duff radius arms. We used a length of all-thread, some washers, lithium grease, and nuts to press the bushings into the supplied head unit.
The head units bolt to the axlehousing using new polyurethane C-bushings. Getting them oriented in the new rear head unit and factory front radius arm C-unit is easy since each bushing is marked either front bottom or rear bottom depending on orientation.
With all the polyurethane bushings in place and lubed with a little more lithium grease, we bolted the new and original radius arm C-units (now coated in Duff Blue spray paint) to the axles and torqued the four retaining bolts to spec (90-110 lb-ft). This is the back of the new head units where the radius arms will bolt in place.
With the head units in place we lubed up the huge Heim joints and jam nuts and screwed them into the control arms. We then used the supplied bolts, washers, and misalignment washers to bolt the control arm hanging under the Bronco. Then you can lift up the control arm and insert the supplied Grade 8 bolts to attach the radius arm to the head unit. With one side in place you can repeat the last few steps on the other side. Flexing the axle side-to-side on the screw jacks helps with lining up the holes on the radius arms and head units.
With the left- and right-side lower coil spring cups and retaining plates cleaned up and painted blue, we then installed the new James Duff progressive-rate coil springs.
The springs are retained up top by one piece of metal with a nut welded to it. The strap bolts to the coil bucket, and the James Duff Stage Two Long Travel Shock Hoops for 1966-77 Bronco were welded to the chassis.
A little media blasting and a coat of fresh chassis-black POR 15 paint make the 11-leaf progressive-rate rear springs from James Duff look as good as new. The bushings in these springs seem to have aged well, but we won’t hesitate to replace them if they feel loose once we’ve put a few hundred miles on the Bronco.
Back when they were just a prototype in 2000, the Stage Two Long Travel Rear Shock Mounts for 1966-77 Bronco were installed on this Bronco. This generally requires a 2- or 3-inch body lift to clear. We are pretty firmly against body lifts and want the Bronco to sit down a touch over where it was sitting before, so we notched into the body a bit for that little extra uptravel. Soon we will build some small sheetmetal boxes to enclose the top of the shock mounts. Shock installation was as simple as sliding the shock in place and installing a few bolts.


James Duff
Sequim, WA 98382

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