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1973 Jeep CJ-5 - The Mutt

Harry Wagner | Writer
Posted September 1, 2009

Equal Opportunity Jeep

In 1951 the military awarded Ford with a contract to replace the M38A1. The new 1/4-ton 4x4 was called the Military Utility Tactical Truck, or MUTT for short. The MUTT utilized coil springs and independent suspension front and rear. Despite the horizontal grill slots, the MUTT is often mistaken for a Jeep. Manny Alvarez's CJ-5 is the real Jeep mutt though, not those rollover-prone Ford military vehicles. Manny picked up the CJ-5 in 2005 with a 21/2-inch lift and 33-inch tires. He purchased the Jeep to use for hunting trips, but after one trip to the Chile Challenge in Las Cruces, New Mexico, Manny was hooked on rockcrawling.

The first order of business was to box the stock frame to withstand the rigors of rockcrawling around Manny's hometown of Deming, New Mexico. New spring hangers were then added to accommodate the Alcan YJ springs fitted with Orbit Eye bushings for unhindered flex. The springs were slung over the axles and the shackles for the front suspension were relocated aft of the springs and under the frame. A traction bar was added to the rear suspension to limit axlewrap with the spring-over. Custom upper shock mounts are used up front in conjunction with long-travel Rancho RS5000 shocks, while no shocks have yet found their way under the back of the CJ-5. The new suspension stretches the front axle forward 4 inches and the rear axle back 6 inches with relocated spring hangers. The resulting 94-inch wheelbase accommodates 36-inch Super Swamper IROKs mounted on Mickey Thompson Classic Lock wheels. The wheels are a streetlock design, so Manny removed the stock rings and had wider, thicker rings CNC cut to protect the bead of the wheels.

The drivetrain is where things really begin to get interesting. The stock AMC 304 V-8 was retained. Howell throttle-body fuel injection now sits atop the Edelbrock Performer intake manifold and a Performance Distributors DUI ignition keeps it running smooth. The AMC engine is mated to an SM465 ripped from a Chevy pickup and mated with an Advance Adapters bellhousing and Centerforce clutch. The transmission's 12-inch length and 6.55:1 First gear make it an excellent choice for the short-wheelbase CJ-5. The short length allowed Manny to use a Klune-V underdrive between the transmission and the factory Dana 20 transfer case, which has been fitted with 3.15:1 Tera Low gears, twin sticks, and an Advance Adapters heavy-duty output shaft. "I thought that the transfer case gears would make the crawl ratio low enough," Alvarez admitted. "But it wasn't, so I added the Klune-V." The drivetrain sits atop custom crossmembers and provides an astounding 376:1 crawl ratio that offers enough control for the most technical of rockcrawling.

All that torque is routed through a 12-inch-long CV-equipped Tom Wood rear driveshaft to a Ford 9-inch rear axle. The 9-inch is fitted with 4.56 gears, an ARB Air Locker, 31-spline axle shafts, and Moser disc brakes. Manny says that the next step is to shave the bottom of the 9-inch for more ground clearance. Up front, he is running an axle from a Toyota mini-truck. The Toyota axle is light and offers great ground clearance on the trail. "Most of the guys that I wheel with drive Toyotas," Manny noted. "So it made sense to use parts that they had available and were familiar with." It is also plenty strong with the addition of 30-spline Longfield chromoly axles, 4.56 gears, and an ARB Air Locker. The Toy axle housing has been reinforced with knuckle gussets, a truss, and differential armor from Marlin Crawler. It's steered by a Saginaw power steering box on a reinforced frame mount. From there a 3/16-inch-wall 1026 DOM drag link and tie rod fitted with 3/4-inch rod ends connect to 4x4Labs steering arms that put the tie rod behind the axle and out of harm's way.


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