2000 Ford F-350 Super Duty - Project Plain Jane - Part IPosted in Project Vehicles on August 6, 2004 0) (
Meet Jane. As you can see, she isn't real pretty. But as your mom might have said, though she's kind of plain, she's got a great personality. Actually, she's got multiple personalities, or will have. She'll be a tow rig, a camper, a four-wheeler and a part time daily driver. So we'll focus on the things we did to change the performance of the truck.
This particular Plain Jane is a 2000 Ford F-350 Super Duty with a Power Stroke diesel. Jane started life with exactly one option on her window sticker-the diesel engine. She is as plain as they come: a white regular cab with rubber floor mats and wind-up windows. But along with her winning personality, she's got a great build: a six-speed manual transmission plugs in behind the Power Stroke and feeds a lever-controlled NP271 transfer case. Axles are a Dana 50 up front (with hubs) and a Ford 10.25 in the rear. Stock gearing is 3.73 with open diffs.
Jane has many shoes to fill. The truck's main use is for towing a 9,000-pound (when loaded) enclosed trailer filled with a Jeep or a race car. On these tow trips she needs to be comfortable enough to live in, yet still be compact enough to perform as a daily driver when needed.
Obviously, Jane's got to have 'wheeling ability. She must be capable of 'wheeling into, and out of, some nasty places, and suitable for traveling in Baja. In this case, having a terrific tow truck is more important than building an all-conquering 'wheeler so the truck won't become an all-out flex-mobile. A high-clearance, good riding but stable suspension is needed for Jane's mission in life. Aggressive tires and lockers will make up for any lack of flex in the rough stuff.
The first thing on our must-modify list was the stock suspension. We figured we should add a lift system, the better to fit bigger wheels and tires. Fabtech Motorsport's five-inch suspension kit was chosen to get Jane up and level. Fabtech Motorsports is a Southern California company that has been around for 15 years. Until recently, the company's main focus has been on off-road racing and 2WD pre-runner-type trucks. Today, the company is incorporating its racing lessons and technology into bolt-on suspension systems for 4x2 and 4x4 trucks. Using computer-aided design and CNC equipment, the company's engineers are cranking out some state-of-the-art suspension systems.
The Fabtech leaf-spring pack for the Ford Super Duty, for instance, is a good example of this. Ten leaves make up the front springs, compared to half that many used in most other suspension lifts available for the Super Duty. Fabtech claims that by using thinner leaves and more of them, its engineers can build a spring pack that is more flexible, offers more articulation, and a smoother highway ride, yet still retains its load-handling capability. This philosophy, along with features like a military-wrapped main leaf for strength, nylon anti-friction pads between each leaf, floating leaf clamps for articulation and vulcanized rubber bushings instead of squeaky polyurethane, lead us to choosing the Fabtech product for pumping up Jane. Before-and-after testing has revealed some mixed results. Check it out.
When driven quickly on curvy paved roads, the stock Ford exhibited a lot of understeer. The soft, two-leaf front springs allowed for a lot of body lean and push in fast corners. The new Fabtech springs took care of that problem. The truck handles mountain roads at a faster clip with much more stability and aplomb now. This new-found stability also improved handling with a load, especially when towing the trailer. The ride, which was pretty good stock, is as good as before once the front shocks got sorted out. It's reassuring, when hitting a big bump, to picture those thick spring packs taking the hit instead of the stock two-leaf setup.
The most noticeable off-pavement improvement is in the hillclimb, which has a 38 percent grade. Wearing stock wheels and tires, the Ford failed to surmount the hill at a First gear crawl, or in Second or Third gear low range. The truck experienced lots of axle chatter, wheelhop, and suspension bottoming in the faster gears. In high-range Second gear, the truck stalled just short of the top. In granny/high-range it finally got over the top, but with much fuss. Momentum definitely played a part in its success.
A return attempt at climbing the hill with the modified truck, which also sported its new bigger tires, was like night and day. The truck crawled up hill in low-range/granny with zero throttle input. It behaved like a tractor, exhibiting no axle hop or chatter, and only slight tire spin as the new Super Swamper TSLs searched for traction on the steep hill. It was a huge improvement.
Fabtech's claim that it builds a more flexible spring, and that it offers more articulation, proved inconclusive in our tests-at least when compared to the stock springs. Results from forklift tests revealed that the truck does not flex as well as it did stock. But since Jane isn't supposed to be a flex-monster, this isn't a big problem. Ford's live-axle design still articulates far better than an independent setup would, so Jane's 'wheeling ability is not limited by this. Overall, the Fabtech suspension's performance is a great improvement over stock and meets all our requirements for Project Plain Jane.
PUTTING IT ON
Installing a lift on a Ford Super Duty is a simple task compared to accomplishing the same job on some other new trucks. This is due to the Super Duty's old-fashioned leaf-spring suspension design. The installation, for instance, took about three hours and was accomplished without any fitment problems. The kit consists of the new front spring packs, along with a drop pitman arm, a drop track-bar bracket, longer antiroll-bar links, longer front bumpstops, and new U-bolts. For the rear, Fabtech offers a choice between rear blocks, ride stiffening add-a-leafs, or whole spring packs. Since Jane's rear springs were new, and they already provided a stiff enough ride when unladen, replacement springs and add-a-leafs were ruled out. The blocks got the nod. Fortunately, Fabtech's lift blocks are a springwrap-friendly one-inch tall. If more carrying capacity is required, then the add-a-leafs or air bags will be installed.
The Super Duty comes from the factory with a pretty serious rake, which the Fabtech kit modifies. With stock tires and the 5-inch Fabtech suspension installed, Jane measured 451/48 inches higher at the front fenders, 3 inches higher at the door handles and one inch higher at the rear fenders. The fact that the truck doesn't measure an honest five inches is possibly due to the 12,000-pound Warn winch mounted to the front end. (This winch, and its semi-hidden bumper mount, will be covered in another installment.) Despite the missing 31/48 inch of lift, the factory rake is gone, and the truck sits level.
New, longer shocks are included in the suspension kit, but we went a step further and installed Fabtech's dual front shock hoop kit. Whoops-bad idea! Equipped with the lift and dual shocks, the Ford's ride is extremely harsh and the thick leaf packs are to blame. This miserable ride was endured for several weeks before one shock was removed from each side as an experiment. The difference was astounding. The ride went back to as good as stock, with no ill side effects. A call to Fabtech confirmed that we had installed the right shocks and that they have received no other complaints about this. They also mentioned that they are about to release a new shock hoop kit, designed to fit rebuildable shocks like Racerunners, Foxes, Bilsteins, etc. This might be advisable for certain applications. For Jane, we're pretty happy with a single, regular shock at each front corner.
Once Jane sat 451/48 inches higher than stock, it was time to fill her commodious wheelwells with some more functional rubber then the stock 265/75R16 skinnies. These were replaced with a set of 36x12.50R16 Interco Super Swamper TSL radials. These tires were chosen for Jane based on experiences with a set of 38-inch TSL radials which lasted 53,000 miles on the 6,800-pound "IFS No More" Chevy (Four Wheeler, March and April '97, April '98). Despite their super-aggressive tread pattern, which is unmatched when the going gets tough, these tires have proven themselves to handle, balance, and last as well as many less aggressive tires. The downside is the noise they generate, which is pretty noticeable in the new Ford, despite the diesel. It's the price you pay for traction.
The OE take-off tires were rated load-range E. Each one could carry 3,415 pounds at 80 psi. The Intercos are load-range C, rated at 2,650 pounds at a cushy 35 psi. For Jane's applications, this rating is sufficient, while the cushier ride and traction comes from a flotation tire. When dealing with a 1-ton truck and the loads they are capable of carrying (campers, fifth wheels, etc.), watch your tire load ratings when changing to a flotation-type tire.
To attach the new Intercos to the truck, Stockton Wheel produced some custom-built 16x10 steel wheels. New Ford Super Duties come with a metric 8 on 170mm bolt pattern. Traditional 611/42 on 8-inch bolt pattern wheels will not fit. All the aftermarket wheels currently available are shiny aluminum with fancy styled centers. Stockton's plain black, industrial-strength look is more in keeping with Plain Jane's demeanor. Each wheel weighs 41 pounds, mostly due to the 11/42-inch-thick, flat-plate center. Valve stems are placed inboard, away from pesky rocks, and powder-coat paint will keep them looking good for the life of the truck. The stock Ford center caps still clip to the stock lug nuts.
The Intercos balanced very well on the Stockton rims, but when they were mounted on the truck, it shook all over the place. New Fords also have hub-centric wheels. This means the wheel is centered with the axle centerline via its hub hole, not via the lug-nut holes. Ford OE wheels have a very tight tolerance between the hub and the center hole. When the center holes of the Stockton wheels were measured, they were found to be plus-or-minus 60 thousandths (of an inch) oversize. This allows the tire/wheel to be off-center from the axle centerline, big time. With a 36-inch tire, that's a big shake. By shimming the wheels with a feeler gauge before tightening the lug nuts, the wheels can be centered and the ride is smooth. But doing so is a real pain. A cure may be to machine the lug-nut holes to take conical nuts so the wheels center via the lug nuts.
With the addition of the Fabtech suspension, Interco TSLs, and Stockton wheels, Jane's needs for improvements in these areas have been satisfied. To date, 10,000 trouble-free miles have been logged on her with these products installed. Next step in our program to enhance Plain Jane's personality: 4.30:1 ring-and-pinions, along with ARB Air Lockers and a Warn winch. So stay tuned. We'll tell you how it works out.
Plain Jane - Part 2
Plain Jane - Part 3
Plain Jane - Part 4