For heavy-duty, Cummins-powered Ram trucks, the front driveshaft is a critical component, but is prone to failure due to a number of factors (dependent on the generation of truck). This point of vulnerability can be costly and fairly problematic if things go south. A system is only as robust as its weakest link, and if that link fails--often the transfer case--the unrestrained drive shaft can move about freely, wreaking havoc. You risk having brake, transmission, fuel lines, wiring harnesses, transmission housing, transmission pan, and even the cab floor torn or ruptured. The repairs, as you can imagine, can be costly.
The Problem with Front Driveshafts on the Cummins
In any four-wheel-drive truck, the front drive shaft presents a unique challenge. Unlike the rear driveshaft, the front driveshaft uses a Constant Velocity (CV) joint to handle the upward angles needed at both ends of the shaft. In most Ram trucks, this joint is specifically a Double-Cardan style CV joint.
Both the transfer case’s output flange and the front axle’s input flange are set at an upward angle. With this configuration, a standard universal joint would bind, so a Double-Cardan joint is used at the transfer case side of the front driveshaft. This joint design is integral to ensuring smooth and constant velocity by maintaining the same angle at each universal joint in relation to the intermediate yoke.
The illustration above shows the ball and socket joint between the universal joints that keep each u-joint at the same angle, relative to the intermediate yoke. This is what makes this joint a “constant velocity” joint.
-Courtesy of Five Nine Fabrication
The Double-Cardan joint is vital to the lifespan of the driveshaft, and regular maintenance—especially greasing per Chrysler’s recommendations—is crucial to avoid catastrophic failure. The ball-and-socket setup between the universal joints is often where failures originate. In many Ram trucks, the front axle continuously drives the front driveshaft, regardless of whether four-wheel drive is engaged. If the ball-and-socket joint fails, the universal joints can become unbalanced, which may lead to the transfer case being severely damaged (literally torn appart).
Greasing this joint can be a challenge as many truck owners will attest. It requires a specialized grease gun tip, and can be difficult to find and access. According to Randy from Five Nine: " In my experience, it’s also difficult to tell whether or not the joint is actually taking grease. I’m not saying you shouldn’t grease this joint, but I am saying that I never get a warm fuzzy feeling after greasing mine. "
Shown below is the needle required for greasing the double-cardan ball, and the location of the grease fitting.
Additional Causes of Driveshaft Failure
Aside from Double-Cardan joint issues, several other factors can contribute to driveshaft failure. For instance, if balancing weights detach during operation, it can create vibrations that lead to damage. Loose bolts can also cause the driveshaft to separate from the drive flange, potentially damaging nearby components. Driving aggressively in four-wheel drive can add additional stress, increasing the likelihood of a failure.
Driveshaft loops are mandatory in most sanctioned sled pulling and drag racing rules!
Driveshaft failure is more than a simple inconvenience—it can set off a costly chain reaction. When a driveshaft fails, as mentioned above, the unrestrained movement can damage essential components like brake lines, transmission lines, fuel lines, wiring harnesses, and even the transmission pan. In severe cases, the driveshaft can impact the cab floor. This can lead to pricy repairs including bell and transmission housings. There is also the potentially dangerous risk of fires caused by ruptured lines and sparks.
Driveshaft Vulnerabilities by Generation
Each generation of Ram trucks has specific vulnerabilities tied to its front driveshaft setup:
1989-1992 (1st Gen) Trucks
The first gen trucks have manual locking hubs and overall tend to have less issues compared to newer trucks. Unless the hubs are locked, the front driveshaft won't be driven. In some rare cases the manual locking hubs can fail "locked" and put your truck at risk of a driveshaft failure. Many first gen owners will convert their newer trucks to manually locking hubs to avoid front driveshaft failures.
1994-2002 (2nd Gen) Trucks
These models introduced the Center Axle Disconnect (CAD) system to prevent the driveshaft from spinning in two-wheel drive. While effective in theory, the CAD system tends to deteriorate over time, leading some owners to remove it to ensure reliable four-wheel drive engagement. Many CAD systems from this generation are no longer working today. Driveshaft failures can still occur even in trucks with a CAD system.
2003-2018 (3rd and 4th Gen) Trucks
These generations are NOTORIOUS for driveshaft failures. Unlike the previous years equipped with locking hubs or Center Axle Disconnect systems, in these generations the front driveshaft remains constantly engaged with the front axle, even without significant torque applied. The continuous motion of these driveshafts increases wear and tear. These generations are known for catastrophic front driveshaft failures and this kit outsells other generations above a five to one ratio.
2019-Current (5th Gen) Trucks
Fifth-generation Ram trucks use a traditional CV joint instead of a Double-Cardan joint at the transfer case. This change may have been introduced to address the issues with Double-Cardan joints. However, CV joints on these trucks are prone to ripped grease boots, particularly if the truck is lifted, exposing the joint to road debris and leading to contamination. Over time, this can cause joint failure and high potential for damage to other expensive components.
The Cost-Effective Solution
Our recommendation is to protect your truck from the catastrophic damage caused during a front drive shaft failure by installing a front drive shaft loop from Five Nine Fabrication. Five Nine Fabrication driveshaft loop kits are made in the USA, feature CNC laser-cut, powder-coated 1/4" steel construction, and costs less than a tank of fuel. All necessary high-tensile hardware is included and no drilling is required. These kits can save you thousands of dollars in damage!
Five Nine Fabrication
Five Nine Fabrication is family-owned and operated. All of our fabricated parts are made in the USA. We strive to create quality, unique ... Read More
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While this device won’t prevent failure, it contains the driveshaft in case it detaches, helping to prevent costly secondary damage to other truck components. For those who have had to spend $6,000 to replace a transmission, it's pretty hard to be comfortable without a loop.
It must be stressed that it is not a substitute for regular inspection and maintenance.
About Five Nine Fabrication
Five Nine Fabrication was founded in 2020 by Randy Schamberger, a mechanical engineer with over a decade of experience in product design and testing for the heavy equipment industry. Randy’s expertise, paired with his long-standing passion for diesel trucks, led him to create specialized parts for Cummins-powered vehicles, addressing unique maintenance challenges faced by truck owners.
Starting with custom parts for 1st Generation Dodge Diesel pickups (1989-1993), Five Nine Fabrication expanded its offerings to include essential products like fan shrouds, radiator covers, cold air intake kits, and driveshaft loops. The latter has quickly become very popular.
All manufactured parts are made in the USA.
