When Jane arrived for her appointment at WCD she was placed in the experienced hands of Eric Knouse. In just five hours, Eric swapped out Jane's wimpy open diffs and installed the ARBs, along with 4.30 ring-and-pinions. In fact, it took longer to drive the 150 miles home, adhering to the required break-in procedure (drive 40 miles, stop, and let things cool an hour) that WCD recommends. Since we want Jane's gears to last as long as her diesel engine, we followed those instructions to the letter.
 After the backlash is set,...  After the backlash is set, the diff is removed one last time for the installation of a set of O-rings, a crucial part of an ARB installation, as one nick or cut to these O-rings and you'll have a leak. While the diff is out for the installation of the O-rings, it's time to drill and tap the housing for the bulkhead fitting that allows air to pass from the flexible blue line from the pump to the copper line on the diff. That done, it's time to button up the front, reinstall the axles, brakes, and wheels and move to the rear 10.25-inch Ford axle. |  The OE speed sensor tone ring...  The OE speed sensor tone ring is fitted to the ARB before installation of the ring gear. The old 3.73 ring had to be removed from the stock carrier to retrieve the tone ring. This toothed ring sends the diff's speed to a sensor mounted in the axle housing. |  When Eric had the diff set...  When Eric had the diff set up properly, he sealed the rearend and filled both front and rear axles with synthetic 90 weight. At 500 miles we changed the lube and hitched up the trailer for an 1,800-mile trip to Colorado and back. We've experienced no problems. The lower gearing of the 4.30s are very welcome when pulling the trailer. Jane once again has the power of a stock truck when pulling a load. |
 Once back home, it was our...  Once back home, it was our job to mount the ARB air compressor and plumb the lines to the axles. Ever look under the hood of a diesel Super Duty? There isn't room for anything. Something had to go. A look around brought our attention to this vacuum canister for the heater-A/C controls. It is mounted near the passenger-side battery on the wheelwell. We figured a vacuum canister can work anywhere so out it went, leaving a nice spot for the compressor. We remounted the canister to the bumper brace in the right front wheelwell. It's tucked well out of the way of the tire and doesn't seem to mind its new home at all. |  Here is the ARB air compressor...  Here is the ARB air compressor in its place next to the battery. It's a tight fit, but what isn't under these hoods? The extra port in the pump was fitted with an air hose disconnect and a flexible air hose for airing up Jane's tires. The plastic yellow hose stays under the hood all the time. |  In the cab, the control switches...  In the cab, the control switches for the ARBs were mounted in this handy area in the dash. It's almost as if Ford planned for them to go there. |
We've rolled 11,000 miles since Eric's work with no hints from those new diffs that they've ever been touched-except when we push the magic traction buttons. That's when Jane becomes separated from all the other Super Dutys running around. Traction with locked diffs puts a 4x4 into another dimension-even a big, heavy 1-ton diesel.After the gear-and-tire swap, one last thing needed to be addressed. We needed to make Jane's speedometer read correctly. This is handy because it's good to know how illegally we are driving, and it's also nice to have the odometer mileage correct so that you can track the truck's maintenance intervals.
Some work here was necessary because even though the swap to 4.30s put the gearing very close to stock with 36-inch-tall tires, the speedo was still off the same amount as when we had 3.73s and just the tall Swampers installed. This is because Fords take their speed readings from a tone ring mounted on the rear diff carrier. It doesn't matter what ring-and-pinion you run, tire size determines the rotation speed of the carrier, hence the tires have control over the signal sent to the computer.
 We were able to get our hands...  We were able to get our hands on one of the first sets of ARB's new Heavy Duty Air Line kits for use on both of Jane's axles. They consist of stout rubber hose that threads into the bulkhead fitting coming off the axle housing. The hose is about four feet long so you can mount it along a frame rail, out of harm's way. A bracket is supplied for this use. From the end of the hose to the compressor ARB's standard blue tubing is used. |  This is Superlift's new TruSpeed...  This is Superlift's new TruSpeed Speed Sensor Calibrator. It only measures about 3x6 inches and has a four-wire hookup. The round thing is a key used to calibrate the unit. The key is inserted into a hole in the case, which has an adjustment screw behind it. The screw is rotated a certain number of turns, depending upon your tire diameter and gear ratio. A chart, supplied with the TruSpeed, tells you how many turns to make. Once the turns are made, your speedometer reads dead-on correct, no matter what size tires or gears you swap to. |  The TruSpeed mounts easily...  The TruSpeed mounts easily with double-stick tape as it doesn't weigh much. We stuck ours onto this support rail behind the large access panel under the steering wheel. The wiring consists of taping two wires into the corresponding two wires coming from the speed sensor on the rear axle. The other two go to a hot lead and a ground-simple. |
We found a cure for our speedo woes with Superlift's TruSpeed Speed Sensor Calibrator. Developed in Iceland, and in use for years there, this magic little black box is the answer to recalibrating modern electronic speedometers found on all new vehicles. With just a four-wire hook-up you can recalibrate your speedo to any tire size and/or any gear ratio. Not only that, the TruSpeed has a toggle switch that allows for two different calibration settings. This allows you to own two different sets of tires of different diameters, and still have your speedo read true no matter which set you're running.
We installed a prototype unit before the instructions were written, but even without instructions, it was easy to install and adjust using roadside mile markers. By the time you read this, TruSpeeds should be available at your local Superlift dealer, complete with calibration charts for all gear ratios and tire combos. So, now we know our 11,000 miles of driving with the ARBs and the 4.30s are dead on.
Installing Warn Premium Hubs on a Super Duty
While testing Goodyear's AT/S vs. MT-R tires, (Four Wheeler, May 2001) we tagged a rock with our right-front locking hub. The OE Ford hubs are made of pot metal and didn't like the rock one bit. A check with our Ford dealer revealed that a new hub lists for $150. We quickly called Warn Industries to see if they made the OE hubs for Ford and if they offered a more realistic price. Warn rep Dan Buffen felt that their Premium Hub (PN 38827) would fit the new Super Dutys, so we gave them a try. Check out the photos to see what we found out. One final note-Jane has manual locking hubs. If your truck is equipped with a pulse/vacuum (automatic) hub system and you want to install regular locking hubs like Warn Premium you must plug the vacuum line with a BB. This fools the computer into thinking the hub is always locked, which is OK. Otherwise, the computer will send a code and your "check engine" light will come on permanently until reset.
Plain Jane - Part 1
Plain Jane - Part 3
Plain Jane - Part 4
 This is what an OE hub looks...  This is what an OE hub looks like after a day of testing tires for Four Wheeler. The hub was junk and couldn't be unlocked. |  The Warn Premium hub is shorter...  The Warn Premium hub is shorter than the OE unit, but all the splines are the same and it is far stronger. And the set of two costs less than one OE piece from Ford. |  The inner body of the Warn...  The inner body of the Warn hub slips into the Super Duty wheel hub with no problem. The supplied inner snap-ring is not necessary on the Super Duty as the stub axle is already held in place behind the locking hub. |
 Here is where we ran into...  Here is where we ran into a problem. One snap-ring is supplied with each hub from Warn. These rings retain the hub body snugly inside the wheel hub. The Ford OE snap-ring is .125 thousandths thick. The Warn ring measures only .06 thousandths. We found that by installing two of the Warn snap-rings, the hub fits firmly in place. |  There is an O-ring that seals...  There is an O-ring that seals the outer hub assembly to the Ford wheel hub. On older Ford 3/4-ton axles (which is what this hub was designed for) there is a flange machined into the end of the wheel hub for the O-ring to seal against. The Super Duty wheel hub doesn't have this flange. The O-ring must seal against the two Warn snap-rings installed earlier. This isn't the smoothest sealing surface. We greased the O-ring well before installing the outer hub assembly. If water or dirt gets past the O-ring, it will only contaminate the locking hub mechanicals. The wheel bearings are still sealed from the hub cavity on a Super Duty, unlike on the older trucks. So far, with lots of winter use, nothing has gotten into Jane's new hubs. |  If you choose to run the stock...  If you choose to run the stock Ford hubcaps, your hubs will look like this because the Warn Premium hubs are shorter than the OE units. It is still easy to turn them. |