2025 Jeep Grand Cherokee Transmission & Axle Gear Ratios

The 2025 Jeep Grand Cherokee continues to offer a blend of rugged capability and refined comfort, with its powertrain options playing a crucial role in delivering this balance. Understanding the transmission and axle gear ratios is key to appreciating how the vehicle performs, whether you prioritize fuel efficiency for daily commutes or maximum towing power for weekend adventures.

Transmission gear ratios

The 2025 Jeep Grand Cherokee primarily utilizes an 8-speed automatic transmission across its powertrain offerings. This advanced transmission is renowned for its smooth shifts and wide gear ratio spread, optimizing both acceleration and fuel economy.

ZF 8HP75 8-Speed Automatic (3.6L Pentastar V6 & 5.7L HEMI V8)

Available axle ratios

The axle ratio significantly influences how the engine's power is delivered to the wheels, impacting acceleration, towing capacity, and fuel efficiency. Jeep offers several axle ratio options for the 2025 Grand Cherokee, allowing buyers to tailor the vehicle to their specific needs.

Note: Axle codes can vary by specific trim and package. Consult your vehicle's documentation for precise identification.

How to identify your axle ratio

Identifying your Grand Cherokee's axle ratio is crucial for proper maintenance, parts replacement, or assessing its capabilities. For most Jeep vehicles, you'll want to check the following:

• Door-Jamb RPO Sticker: Open the driver's side door and look for a sticker on the door jamb or the B-pillar. This sticker often contains a list of RPO (Regular Production Option) codes. For FCA/Stellantis vehicles like the Jeep Grand Cherokee, axle codes typically start with "DM" followed by numbers. Look for codes similar to DM3, DMH, etc. You may need to cross-reference these codes with an online decoder or your owner's manual.
• VIN Decoder: Many online VIN decoders can provide a detailed breakdown of your vehicle's factory specifications, including the axle ratio. Enter your 17-digit VIN into a reputable decoder website.
• Dealer Service Department: If you're still unsure, your local Jeep dealer's service department can look up your vehicle's exact specifications using its VIN.

Towing vs MPG impact

The axle ratio creates a direct trade-off between towing capability and fuel economy:

• Lower Numerical Ratio (e.g., 3.45): This means the driveshaft makes fewer rotations for every rotation of the wheel. It results in lower engine RPMs at cruising speeds, leading to better fuel economy. However, it also translates to less torque at the wheels, which can reduce towing capacity and make the vehicle feel less responsive during acceleration, especially when loaded.
• Higher Numerical Ratio (e.g., 3.70, 4.09): This means the driveshaft makes more rotations for every rotation of the wheel. This provides more torque at the wheels, which is excellent for towing heavy loads, off-roading, and quicker acceleration. The drawback is higher engine RPMs at cruising speeds, leading to lower fuel economy.

When choosing a Grand Cherokee, consider your primary use case. If you tow frequently or tackle challenging off-road terrain, a higher numerical axle ratio is beneficial. For everyday driving with occasional light towing, a lower numerical ratio offers a good balance.

Common issues

While the Grand Cherokee's driveline components are generally robust, like any mechanical system, they can experience wear over time. Some common issues related to differentials and axles include:

• Ring and Pinion Whine: A persistent howling or whining noise that changes with vehicle speed (and sometimes load) can indicate worn or improperly set up ring and pinion gears within the differential. This often requires professional diagnosis and repair, including gear replacement and proper backlash adjustment.
• Carrier Bearing Wear: The bearings that support the differential carrier can wear out, leading to growling noises, especially when turning or under acceleration. This issue can worsen if left unaddressed, potentially causing further damage to the differential.
• Limited-Slip Clutch Wear: If your Grand Cherokee is equipped with a limited-slip differential (LSD), the clutch packs within it can wear down over time, especially with hard use or prolonged neglect of fluid changes. Symptoms include a chattering or clunking noise from the rear end during tight turns, or a noticeable decrease in traction in slippery conditions. Regular differential fluid changes with the correct friction modifier are crucial for LSD longevity.

Regular maintenance, including checking and replacing differential fluid at recommended intervals, can help prevent these issues and ensure the longevity of your Grand Cherokee's driveline components.

Find a driveline shop on Repairius.