Tech / Tech Projects

Desert Bronco (Part 2): Marc Sorger Finishes His Off-Road Race Bronco


In case you’ve never seen a Ford Twin Traction Beam (TTB) front suspension, this is what it looks like. It’s kind of a swing axle deal. The axle beams are mounted to a massive engine crossmember and pivot on two rubber bushings near the center of the frame. That allows the wheels to move independently of each other. The Dana 44 differential is offset to the driver's side, and a slip yoke is used on the long axle side to allow the shaft to change length. A pair of radius arms locate the axle beams front-to-rear, and are tied to the frame with bayonet-style bushings that allow almost unlimited rotation. All this makes the TTB easy to modify for long suspension travel.

Yukon Gear and Axle supplied all of the goodies for the front Dana 44 and rear Ford 8.8 inch axles: Grizzly Locker differentials, 4.56 gears, and bearing kits. Here is the Grizzly locker and gear set in the 8.8-inch rear axle. Yukon provided a low-profile aluminum differential cover for the 8.8.

Yukon Gear also supplied a pair of it Hardcore front locking hubs. The hubs are all-steel with chromoly steel internals, so they’re plenty strong for off-road abuse. They won’t disengage under high-torque applications and default to the locked position when the vehicle is in motion. The Hardcore hubs have a short 1/3-turn engagement, plus low-profile bezels to reduce the chance of damage from rocks and other obstacles.

Marc welded up the eight-point roll cage from 1 3/4 inch DOM steel tubing. The main hoop sits just outside the cab and ties into the cargo area with down bars welded to plates on welded to the floor. The middle X strengthens the cage and also functions as a spare tire carrier.

The Summit Racing seats are tied into the roll cage with these supports made from 2 x 4 inch rectangular tubing.

Two additional bars run from the main hoop across the door openings to the front of the cab. They are welded to plates on the floor.

Here you can see the finished roll cage with the spare tire mounted. Simple, but effective.

Marc selected a pair of G-FORCE Camlock five-point harness. The camlock has a lightweight magnesium case and a high-tech, quarter-turn mechanism that’s easy to use. Each belt will rotate up to 40 degrees and move up and down 10 degrees to conform to the driver's body for extra comfort.

The spindly factory plastic steering wheel was swapped for a beefy Longacre aluminum wheel with a center pad for some added protection when Marc hits the whoops. The Summit Racing 10,000 RPM tach sits dead square in Marc’s line of vision.

Gotta look good for race day, so Marc did some bodywork in preparation for a couple coats of PPG Hot Rod Black flat black paint.

The Bronco’s not even finished a day and Marc’s got it all dirty. Kids. We wager the it (and Marc) will get a whole bunch dirtier after its first short course race at Central Oregon Off-Road Race Park this summer. But that’s what toys are for, right?

In the first segment of Desert Bronco, we introduced Marc Sorger and the 1984 Bronco he was cutting up, er, modifying for desert and short-course racing in his home state of Oregon.

As Marc explained in that story, the 1978-96 full size Broncos are popular as desert racers and prerunner vehicles due to their body-on-frame construction, a Twin Traction Beam front suspension that offers superior wheel travel over a solid front axle, and ability to swallow big engines and drivetrain upgrades. Oh, and they’re cheap.

Marc began the conversion of his ’84 Bronco from old truck to desert racer by adding a Skyjacker Softride two inch lift kit with Nitro shocks front and rear to add some suspension travel and make room for the 33.5 inch tall Maxxis Bighorn tires and Pro Comp Xtreme Rock Crawler wheels. He swapped out the old 302 small block for a 331 cubic inch motor that makes about 350 horsepower, patched the front driver side floor, and installed a set of Summit Racing race seats.

In this segment we’ll show you the rest of the build—eight-point roll cage, axle upgrades and locking hubs from Yukon Gear, bumpers and light bars, some black paint, and a pair of G-Force harnesses.

Marc’s recipe is a great starting point for building a very off-road capable Bronco. Depending on how many creature comforts you retain, you can build a truck suitable for street use as well.

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One Comment

  1. Really cool build, very similar to what I’m building now. Mines a1980, 331 with a 4 speed manual.
    Really was hoping to read what was done for the clutch, no upgrades over stock/oem?

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