The 2021 Jeep Grand Cherokee Trackhawk is a beast of an SUV, boasting a 707-horsepower supercharged V8 and a reputation for dominating both the drag strip and the open road. But what makes this high-performance machine truly exceptional is its robust rear end, engineered to handle extreme torque and deliver unparalleled traction. From its differential to its axles and suspension, the Trackhawk’s rear end is a masterpiece of automotive engineering. In this blog post, we’ll dive into the specifications, performance upgrades, and maintenance tips for the 2021 Trackhawk’s rear end, helping you understand what powers this SUV’s ferocious performance. Whether you’re a Trackhawk owner or an enthusiast, read on to discover how the rear end makes this Jeep a legend!
Understanding the Trackhawk’s Rear End Specifications
The 2021 Jeep Grand Cherokee Trackhawk’s rear end is designed to manage its massive 707-hp 6.2L supercharged HEMI V8 and 645 lb-ft of torque. Key components include a 3.70 rear axle ratio, a standard electronically limited-slip differential (ELSD), and a competition-tuned suspension, as noted by Car and Driver. These elements work together to deliver power efficiently to the rear wheels, ensuring optimal traction and stability during aggressive driving.
The rear differential is a 9-inch unit with a 3.70 gear ratio, paired with 35-spline pinions and 108mm CV yoke to maintain factory driveshaft compatibility, according to Innovative Machining Solutions. The ELSD enhances grip by distributing torque to the wheel with the most traction, making it ideal for high-performance scenarios like drag racing or cornering. The Trackhawk’s rear suspension features a competition setup with Bilstein adaptive dampers, optimizing handling for its 5,363-pound curb weight, per U.S. News.
Performance Upgrades for the Trackhawk Rear End
For enthusiasts looking to push the Trackhawk’s rear end beyond stock performance, aftermarket upgrades offer significant improvements. Here are some popular options:
Billet Rear Differential
A billet rear differential, like those from Black Ops Auto Works, is a bolt-in upgrade with a 3.70 gear ratio and Eaton Truetrac for enhanced traction. These units use 35-spline, 108mm chromoly stub shafts, designed to reuse GForce CV shafts, ensuring durability under extreme torque. No modifications are needed, maintaining factory CV shaft and driveshaft angles to avoid vibration or stress.
Upgraded Axles
The Trackhawk’s stock axles use a 32-spline inner stub and 35-spline outer stub, but they’re prone to damage under heavy torque, especially with wheel hop, as warned by TREperformance. GForce Renegade or Outlaw axles, made from billet steel with anti-wheel hop technology, boost strength for high-horsepower builds. These axles are critical for drag racers pushing beyond 900 hp, where stock components may fail.
Differential Brace and Bushings
To combat wheel hop and excessive rear end movement, aftermarket differential braces and bushings are essential. Solis Racing Group offers braces that stabilize the differential, reducing stress on axles and CV joints. Upgrading to Delrin race bushings, as suggested by BWoody Performance, minimizes lateral movement for a firmer, more responsive ride, especially in high-horsepower setups.
9-Inch Conversion Kits
For extreme builds, a 9-inch rear end conversion kit from The Driveshaft Shop provides a complete solution. These kits include a 9-inch rear housing, 1400HP-rated diff stubs, axles, and an aluminum driveshaft, designed for seamless integration. Such upgrades are ideal for Trackhawks exceeding 1000 hp, ensuring the rear end can handle the power without failure.
Common Rear End Issues and Maintenance Tips
The Trackhawk’s rear end is robust but not invincible, especially under aggressive driving conditions. Wheel hop, a common issue with high-torque vehicles, can damage axles and differentials, as discussed on Jeep Trackhawk Forum. Owners report failures after high-performance runs, with symptoms like humming noises or black oil with metal shavings indicating a “toasted” differential.
To maintain your Trackhawk’s rear end:
- Inspect Regularly: Check axles and stub shafts for spline wear after aggressive driving, as advised by TREperformance. Early detection can prevent catastrophic failure.
- Upgrade Bushings: Replace soft factory bushings with aftermarket options to reduce wheel hop, per BWoody Performance.
- Monitor Fluid Levels: Ensure the differential fluid is clean and topped off, as contaminated fluid can lead to premature wear, noted in Jeep Trackhawk Forum discussions.
- Avoid Wheel Hop: Use proper launch techniques and consider suspension upgrades like BWoody’s control arms or Eibach lowering springs to minimize tire chatter, available at Solis Racing Group.
Why the Trackhawk’s Rear End Stands Out
The Trackhawk’s rear end is engineered for performance, balancing street comfort with track-ready capability. Its 3.70 gear ratio and ELSD provide excellent traction, while the competition suspension ensures stability at high speeds. Compared to rivals like the Porsche Cayenne Turbo S, the Trackhawk’s rear end is optimized for straight-line speed, achieving 0-60 mph in 3.3 seconds and a quarter-mile in 11.7 seconds at 116.2 mph, per MotorTrend. However, its heavy weight and high torque demand careful maintenance to avoid driveline issues, especially for modified vehicles.
The Trackhawk Rear End
The 2021 Jeep Grand Cherokee Trackhawk’s rear end is a critical component of its legendary performance, designed to harness 707 hp with precision and durability. From its stock 9-inch differential to aftermarket upgrades like billet diffs and high-strength axles, the Trackhawk’s rear end can be tailored to handle extreme power levels. By investing in upgrades and following maintenance best practices, owners can ensure their Trackhawk remains a dominant force on the road or track. Ready to upgrade your Trackhawk’s rear end? Check out options at Black Ops Auto Works or visit Jeep Trackhawk Forum for community insights. What’s your favorite Trackhawk mod? Share in the comments!