Understanding SRT 4 High Performance Axles for Racing

Understanding SRT 4 Axles

SRT 4 axles have become a popular performance upgrade for certain vehicles. SRT stands for Street and Racing Technology, a high performance parts division created by Dodge. The "4" refers to the 4 wheels that make up the axle assembly.

SRT 4 Axle Design

An SRT 4 axle is built for handling greater levels of power and torque than a standard OEM axle. This is achieved through a beefed up ring and pinion gear set, upgraded axle shafts, a stronger differential, and a reinforced axle housing.

The ring and pinion gears on an SRT 4 axle are often made from superior materials that can withstand more stress and wear. 9310 or 300M steel are common choices offering increased durability. The gear ratio may also be numerically higher for better acceleration.

Axle Shafts

The axle shafts transmit rotational power from the differential to the wheels. SRT 4 axle shafts are made from strong chromoly steel instead of ordinary iron. Chromoly has higher yield and fatigue limits, meaning it can endure more torque without permanently deforming or cracking.

Besides the upgraded material, SRT 4 axle shafts often have a larger diameter for extra strength. They may also utilize thicker splines and upgraded universal joints for reliability under extreme loads.

Differential

The differential allows the two axle shafts to spin at different rates when going around turns. Performance differentials in SRT 4 axles feature more robust components to handle hard use.

Competition grade carriers, ring gears, spider gears, and side gears increase the torque capacity inside the differential. Stronger fasteners help keep all the parts intact if when experiencing very high driveline shock loads.

Axle Housing

The axle housing contains all the internal parts and keeps everything properly aligned. SRT 4 axle housings are typically made from heavy gauge steel for enhanced durability.

In addition to thicker housing walls, they also utilize larger axle tubes with increased diameters. This provides more support for the axle shafts under extreme torque loads to prevent deflection or distortion.

SRT 4 Axle Benefits

Upgrading to SRT 4 axles offers several advantages for high performance driving:

• Handles more power from engine modifications
• Improves acceleration with numerically higher gear ratios
• Increases top speed potential
• Reduces wheel hop under hard launches
• Enhances high speed stability and cornering grip
• Holds up better to repeated drag strip passes
• More reliable with tougher components

Installation Considerations

Swapping SRT 4 axles into a vehicle takes some preparation for proper fitment and operation:

Component Compatibility

The axle housing ends need to match up with the vehicle's suspension and brake components. This includes attachments for control arms, shocks/struts, brake lines, wheel speed sensors, etc. Some modifications may be required for correct mounting.

Driveshaft Angles

Verifying ideal driveshaft angles is crucial to prevent vibrations and premature wear of U-joints or slip yokes. This may require adjusting pinion angle shims or tweaking suspension geometry.

ABS Sensor Rings

Many performance axles don't include wheel speed sensor rings. This requires sourcing compatible ABS rings and properly installing them on the axles to maintain anti-lock brake functionality.

With some preparation and adjustments, SRT 4 axles can significantly improve a vehicle's straight line and cornering performance. Their stronger internals allow enthusiasts to better put power down and handle more extreme driving situations.

FAQs

What vehicles can you install SRT 4 axles in?

SRT 4 axles are most commonly swapped into high horsepower Dodge vehicles like Vipers, Challengers, Chargers, Rams, and Jeeps. But with custom fabrication they can potentially be adapted to other performance vehicles.

How much power can SRT 4 axles handle?

It depends on the specific axle design and components used, but 800+ horsepower is not uncommon for SRT 4 axles intended for drag racing applications.

Do you need a different gear ratio with SRT 4 axles?

Not necessarily, but numerically higher gear ratios in the 3.70+ range are popular to help improve acceleration. The ring and pinion gears are built to handle the lower ratios.

What maintenance do SRT 4 axles require?

SRT 4 axles are built for hardcore use but still require periodic fluid changes to keep the differentials operating smoothly. Upgraded components can better tolerate debris but occasional inspection is still a good idea.