12 Front Axle Upgrades - Axleshaft AlternativesPosted in Product Reviews on May 16, 2014
The front axleshaft assemblies in your solid-axle or IFS 4x4 were designed to hold up to the loads of the vehicle in stock form. Add larger wheels and tires with more traction, and the increased stresses can result in broken axleshafts, U-joints, or CV joints. If you’ve modified your rig’s engine to make more horsepower, this can escalate the carnage. Same goes for doubling the final drive ratio and/or adding deeper axle gears. IFS suffers from an additional problem. If you’ve added a lift to your IFS rig, the angle of the half-shafts has probably increased beyond what the factory CV joints can handle. This often results in premature failure or breakage of said items.
The obvious option is to upgrade your rig’s axleshafts. Your stock front axleshafts may be made from 1040 or maybe even 1050 material that has probably been induction-hardened. This process hardens the steel to a certain depth by using alternating current. Aftermarket alloy steel axleshafts are often larger in diameter, they’re designed for heavy-duty use, have better splines, and they’re made from steel that has had certain alloy elements added to them during their manufacture to increase strength. Alloy elements include nickel, chromium, and molybdenum, among others. The first two numbers in an axle grade refer to the alloy and the last two refer to the carbon content. The 1xxx group numbers are primarily the carbon group, the 4xxx has many chromoly members, and the three-number designations are considered aircraft-grade steels. Some of these alloy steel axleshafts are through-hardened. Through hardening includes baking them in an ovenlike machine to harden the entire thickness. Some axleshafts are through-hardened and induction-hardened.
Whether you have IFS or a solid axle, installing stout aftermarket axleshafts is only half the job if you don’t upgrade the U-joints or CV joints. The brawn of the axleshafts will simply make the two aforementioned items the weak point. Fortunately, the aftermarket has you covered there too. Some axleshafts use larger factory-style U-joints, while others use beefy aftermarket U-joints or CV joints. Conversely, using beefier U-joints or CV joints doesn’t make much sense without an axleshaft upgrade. Many aftermarket manufacturers offer a complete axleshaft package that includes everything you need for one-stop shopping.
What now? Well, we’ve collected a few select products from several aftermarket manufacturers (more products may be offered, so be sure to visit each company’s website) that will give you a look at what you can buy to make your frontend stronger.
What’s available: RCV offers CV axleshafts for a variety of IFS applications. The axleshaft, housing, bearing cage, and inner race are manufactured with aircraft-quality high-alloy steel. The design allows for tight steering angles up to 45 degrees and an articulation angle of 28 degrees. These units are low maintenance and come with a cast polyurethane cap that has far greater resistance to punctures and tears than a rubber CV boot. RCV also offers CV joint shafts for some solid axle applications, and RCV says that they eliminate U-joint binding and they’re tested to be twice as strong as original equipment axles.
More info: 815/877-7473, rcvperformance.com
2. Alloy USA
What’s available: The company says that these axleshafts are up to 40 percent stronger than stock 1040 axleshafts. These 4340 chromoly shafts are heat-treated, tempered, and induction-hardened. They come with a 10-year limited warranty and are available for GM, Ford, Jeep, and International applications. Alloy USA also offers cold-forged and serviceable U-joints for some applications.
More info: alloyusa.com
What’s available: Available for Dana 44 and Dana 60 applications, CTM U-joints are legendary for their toughness. Each joint is made from 300M chromoly steel and is heat-treated for even more strength. There are no needle bearings to crush in the CTM joint. Instead, it uses bronze sleeves. The joint is greasable and rebuildable. CTM also offers 300M axleshafts in both standard and custom applications.
More info: 760/450-0006, ctmracing.com
4. Moser Engineering
What’s available: Moser Max axleshafts fit Dana 44 and Dana 60 axles. Each shaft is made from aircraft-quality 4140 alloy steel, is through-hardened, and is machined for full-circle clips. The axleshafts have a larger yoke area, yet they are said to still turn at up to a 43-degree radius.
More info: 260/726-6689, moserengineering.com
What’s available: For the Dana 60, Dynatrac’s Pro 60 inner and outer 35-spline axleshafts are available in Standard Alloy and Competition Alloy configurations. Standard shafts feature induction-hardened alloy steel and use a Spicer 1480 series U-joint. Competition shafts feature higher grade materials, heat-treated yokes, and include a CTM U-joint. Dynatrac also offers a Pro Max 40-spline upgrade as well.
More info: 714/596-4461, dynatrac.com
6. Ten Factory
What’s available: Forged from 4340 chromoly steel, these axleshafts are available for Ford, GM, Dodge, and a wide range of Jeep applications. The axleshafts are designed by the company’s engineers for specific applications. The company says that this allows “tuning” of the diameters to equalize the ductility or “give” of the short- and long-side axleshaft, which extends shaft and U-joint life.
More info: 800/934-2727, tenfactory.com
7. Yukon Gear & Axle
What’s available: Available in a wide range of applications, Yukon axleshafts are forged from 4340 material and heat-treated for high tensile and yield strength. The company says that the shafts have increased material in the yoke area and rolled splines, which offer a 30 percent strength increase over cut splines.
More info: 888/905-5044, yukongear.com
8. G2 Axle & Gear
What’s available: Axleshafts for Dana 30, Dana 44, and Dana 60 axles. They’re forged from high-tensile-strength 4340 chromoly material, machined to accept full-circle clips, and have a dual heat-treat process. The U-joint in each axle is already pressed in for easy assembly.
More info: 310/900-2687, g2axle.com
9. Poly Performance Axles
What’s available: Offered are 4340 chromoly axleshafts for the Toyota FJ40 and FJ60. These shafts are made from 4340 chromoly material and feature rolled splines and total elimination of the C-clip on the Birfield-side of the axle.
More info: 805/783-2060, polyperformance.com
10. Nitro Gear and Axle
What’s available: Available for Dana 30, GM 8½-inch, and Dana 44 axles in Jeep, Ford, GM, and International applications. These forged axleshafts are made from 4340 chromoly material and the company says that they have thicker material where it counts. Each kit comes with the needed 760X U-joint.
More info: 916/673-6464, nitro-gear.com
What’s available: Trail-Gear offers the Dirty 30’s Birfield kit for the Toyota pickup, 4Runner, FJ40, and FJ60-62. The company also offers the Rock Assault for the FJ80, Nissan Patrol, and Suzuki Samurai. All have forged 4340 chromoly shafts and 300M chromoly steel Birfield internals.
More info: 877/494-8697, trail-gear.com
12. Longfield Super Axles
What’s available: Longfield offers rebuildable 300M U-joints for Dana 44 and Dana 60 applications, and they feature a high-impact aluminum nickel bronze bushing and full-circle C-clips. The company also offers other axle products including Super Sets that include a set of Birfields and a set of inner axles made from 4340 and 300M material.
More info: 877/494-8697, longfieldsuperaxles.com
Pros and Cons
The obvious upside to all of the beefy axle technology is the superior improvement in strength. Upgrading your front axleshafts may solve your problems in said area on the trail, while snow plowing, pushing through mud on the ranch, or abusing your 4x4 on the job site. There may be some increased maintenance (lubrication) required on some U-joints and CV joints, but other than the higher price (as compared to a stock replacement axleshaft assembly), we can’t think of a reason not to upgrade.
Torn CV Boots
If you have a rig with factory CV-jointed axleshafts, keep a close eye on the CV boots. These boots are used to protect the joint from things like water and dirt. A boot can wear out over time and tear, or it can be damaged if it’s snagged on something off-road. If the boot fails, it will significantly hasten the demise of the joint. There are kits available from Dorman Products (dormanproducts.com) that will allow you to install a new boot with a minimum amount of hassle.
Most of the time, wheelers turn to the aftermarket for axleshaft upgrades. Sometimes, it’s possible to turn to the salvage yard. Example? If you want to get rid of the weak CV-style front axleshafts in your V-8-powered ’93-’98 Jeep Grand Cherokee ZJ, you can swap them out for the stouter U-joint-style axleshafts from the non-vacuum-disconnect Dana 30 found in the Jeep Grand Cherokee, Wrangler TJ, or Cherokee XJ