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Project Hot Dog, Part 2Tearing into our 2 1/2-ton Rockwell axles. From the February, 2009 issue of Jp By John Cappa Photography by John Cappa
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Don't even think of running Rockwells on your Jeep unless you're flogging tires that are 42-inchers or larger. In the last issue, we started the suspension on our budget big Jeep project. The finishing touches on the suspension will be covered in the next issue. Our J-truck is getting 49-inch Super Swamper Irok tires, so we needed some cheap axle beef that could stand the weight of our J-truck and the leverage of the tires. Our 304 V-8 is hardly a drivetrain ripper, but lesser axles would have cost us more in the long run. There are only four reasons to run 2 1/2-ton axles on your Jeep: They're cheap, easy and inexpensive to modify, and not likely to break. The Rockwells already come with 6.72 gears, which are perfect for big tires, they have huge nearly unbreakable components so you don't have to spend a mint on custom wizardry, and they are easy to find and inexpensive when compared to what you might pay to purchase and build a heavy-duty front and rear axle combo. For more info on how to pick the right Rockwells, check out "Deuces Wild" (May '03).  We found plenty of Deuces...  We found plenty of Deuces in the South and Midwestern United States, but the shipping on these pigs was gonna kill us. Then we found Antelope Valley Equipment and Truck Parts in Lancaster, California, which is only a hop and a jump away from Los Angeles. The company has rebuilt-in-crate 2 1/2-ton axles, among other parts and components. We swung out to the desert, had Norman Gorelick load a pair of used Rockwells in the back of our tow rig, brought 'em home, and tore 'em down.  You and a buddy ain't lifting...  You and a buddy ain't lifting these axles. We've heard all kinds of different weights, but the latest is that the stock front weighs in at nearly 850 pounds and the fully dressed rear is almost 700 pounds. You'll need a forklift or an engine hoist to even move them. Our axles were right off the truck and slathered in grease, dirt and several layers of paint, so we scraped and scrubbed them down first.  At the ends, Rockwell axles...  At the ends, Rockwell axles are pretty much the same as any Dana/Spicer axles, only with larger parts. Dumping the drum brakes saves 160 pounds per axle. The front backing plates simply unbolt from the knuckles. The drums attach to the hubs with bolts and the six wheel studs. You can pound out and reuse the studs without the drums. If you're real butch, you can use a pipe wrench to remove the hub nuts; otherwise, use 3-inch eight-sided NAPA socket number M-1907 to disassemble and adjust the wheel bearings.  Rockwell front and rear centersections...  Rockwell front and rear centersections are identical. We pulled both of ours out with an engine hoist so we could install a pair of Tractech Detroit Lockers. The carriers feature threaded bearing adjusters similar to what you'll find in a Ford 9-inch or GM 14-bolt. We noted the backlash of the large helical-drive gear and marked the adjusters and bearing caps so we could put it all back together correctly after we were done tinkering inside.  With the carrier removed,...  With the carrier removed, simply unbolt the two halves and replace the spider gears and thrust washers with the Detroit Locker. When you're done, you can reassemble the case. The bolts should be gunned down and safety-wired. Don't forget to remove the Detroit Locker shipping bolt once the carrier is all together (see wing nut on top).  The carrier caps feature alignment...  The carrier caps feature alignment pins so you know you're assembling everything properly. Using a long screwdriver, you can adjust the carrier bearing preload to the marks you made before disassembly. The bearing caps should be torqued to 175 lb-ft, and the adjuster locks should be set at 25 lb-ft. All of these bolts need to be safety-wired when you're done. We also used thread-locking compound.  With the centersections out,...  With the centersections out, we set to work on the housings. There are several companies that offer weld-on high-clearance bottoms. The stock rounded one is free and fine for our needs. We welded up the drain plugs inside and out, then ground them down for smooth rounded-bottom axles and slapped in the centersections using silicone to seal the mating surfaces.  Rockwell front axles have...  Rockwell front axles have seals just inboard of the knuckles. USA 6x6 has new replacements to keep the gear oil out of the knuckle cavity. We used a seal puller attachment and slide hammer to pop out the retainers so we could replace the seals.  Our knuckle boots looked like...  Our knuckle boots looked like they had been blasted with a shotgun. We ordered some new boots from Norman at Antelope Valley Equipment and zipped them up to keep water and dirt out of the knuckle joints and bearings.  A grader-operating buddy of...  A grader-operating buddy of ours turned us on to Red-i super premium grease. It's really sticky and works killer for chassis and wheel bearings in dirty and wet off-road conditions. Heck, it's for tractors. Each knuckle took about two tubes of grease before we slammed in the shafts. The spindles are sealed with silicone, then bolted on.  The brake backing plates on...  The brake backing plates on rear Rockwells are riveted in place. We went to work with our Matco torch to free our rear axle of its drum brakes and 160 pounds, just as we did in the front.  The rear hubs can be easily...  The rear hubs can be easily flipped in or out for a wheel-mounting-surface measurement of 79 1/2 or 69 1/2 inches. However, it doesn't make much sense to do the machining needed to flip the front hubs inward for the narrower wheel-mounting-surface width (69 1/2 inches) only to use wheels with a 2-inch backspacing. We needed new wheels anyway, so we left the hubs flipped out on the front and back and will run wheels with 7 inches of backspacing. We'll still have the same overall width but without spending all the time, money, and labor involved in flipping the front hubs or narrowing the front housing.  The rear hubs can be easily...  The rear hubs can be easily flipped in or out for a wheel-mounting-surface measurement of 79 1/2 or 69 1/2 inches. However, it doesn't make much sense to do the machining needed to flip the front hubs inward for the narrower wheel-mounting-surface width (69 1/2 inches) only to use wheels with a 2-inch backspacing. We needed new wheels anyway, so we left the hubs flipped out on the front and back and will run wheels with 7 inches of backspacing. We'll still have the same overall width but without spending all the time, money, and labor involved in flipping the front hubs or narrowing the front housing.  We opted for inexpensive pinion...  We opted for inexpensive pinion brake kits from USA 6x6 for the front and rear axles of our J-truck. These brakes can be mounted on the front or backside of the axles and even clocked for suspension, frame, engine and steering clearance. The compact caliper-mounting bracket bolts to the pinion flange. We needed to grind the bracket a little to get all four holes to line up properly. You may also want to upgrade to slightly longer bolts to get full thread contact. While you have the yoke removed, it's a good idea to replace the pinion seals. USA 6x6 sells these, too.  The 10-inch vented rotor is...  The 10-inch vented rotor is drilled to fit on the backside of the Rockwell pinion yoke. To install it, you'll need to remove the dust shield on the yoke. Slide on the loaded Wilwood four-piston caliper, the yoke and the rotor all at once, or you won't be able to get all the mounting bolts in their holes. Once the assembly is in place, you'll need a 1 1/2-inch socket (same one used on the lug nuts) to gun down the pinion yoke to 300-400 lb-ft. Stopping Deuces
Running the heavy stock drum brakes on an off-road Jeep that will see mud and water didn't seem like a good idea. Plus, we didn't like the extra 320 pounds that the four-wheel drums added to our axles or the wheel selection limitations. To keep our axles cheap and light and even allow the use of 15-inch wheels, we went for the USA 6x6 pinion brakes. They feature Wilwood pads that are designed specifically for the extra heat that a pinion brake can produce. They're also less grabby than conventional brake pads commonly found on regular automotive applications. The main downfall of pinion brakes is that you can pretty much kiss street use goodbye. The pinion brake rotors spin 6.72 times faster than wheel-mounted rotors would. They make a lot of heat when the brakes are applied. If you plan to drive on the road, then USA 6x6 also offers several street-friendly wheel-mounted disc kits for substantially more coin.
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