2017 Jeep Grand Cherokee Transmission & Axle Gear Ratios

The 2017 Jeep Grand Cherokee (WK2 generation) is a versatile SUV renowned for its balance of off-road prowess, luxury, and towing capabilities. A key component of this flexibility is its advanced powertrain, which mates powerful engines to modern 8-speed automatic transmissions and robust drive axles. Whether you are climbing rocks, towing a heavy boat, or commuting on the highway, understanding your Jeep's gear and axle ratios is crucial to knowing exactly what your vehicle is capable of.

Here is the complete guide to the 2017 Jeep Grand Cherokee transmission and axle gear ratios.

Transmission gear ratios

For the 2017 model year, the Jeep Grand Cherokee exclusively utilized 8-speed automatic transmissions across all engine options. The 3.6L Pentastar V6 was typically paired with the Chrysler-built 850RE (or 845RE), while the heavier-duty 5.7L V8, 6.4L V8 (SRT), and 3.0L EcoDiesel utilized the robust ZF 8HP70.

Both variations of this 8-speed transmission utilize the exact same internal gear ratios, providing an exceptionally aggressive first gear for off-the-line acceleration and multiple overdrive gears for highway fuel economy.

8-Speed Automatic (850RE / 845RE / ZF 8HP70)

Available axle ratios

Jeep tuned the final drive (axle ratio) of the 2017 Grand Cherokee to match the torque curves of its various engines. Because the 8-speed transmission has such a deep first gear and tall overdrive gears, the Grand Cherokee doesn't require ultra-steep axle ratios (like a 4.10 or 4.30) to achieve excellent towing limits.

Note: Jeep does not use traditional "RPO codes" like GM. Instead, the final drive ratio is generally fixed to the engine selection for the 2017 model year.

How to identify your axle ratio

Unlike General Motors vehicles that feature a handy RPO code sticker in the glovebox or door jamb, FCA/Stellantis vehicles require a slightly different approach to verify driveline specifications.

1. VIN Decoder or Build Sheet: The absolute best way to identify the factory axle ratio on your 2017 Jeep Grand Cherokee is to run the Vehicle Identification Number (VIN) through an FCA build sheet tool or a trusted VIN decoder. Mopar provides official equipment listings online if you input your VIN.
2. Axle Tag: If you suspect the axles have been swapped or modified, you will need to crawl underneath the rear of the Jeep. Look for a barcode sticker or a stamped metal tag affixed to the rear differential housing cover bolts. This tag will typically display the ratio (e.g., "3.45") printed directly on it.
3. Window Sticker: If you still have the original Monroney window sticker in your glovebox, the final drive ratio will be listed under the standard or optional equipment powertrain section.

Towing vs MPG impact

The relationship between your axle ratio, towing capabilities, and fuel economy is a classic automotive compromise.

Numerically lower ratios (e.g., 3.09) are "taller" gears. They allow the engine to run at lower RPMs at highway speeds. This translates to significantly better fuel economy (MPG) and a quieter cabin on long road trips. However, it reduces the mechanical torque multiplication sent to the tires, making the vehicle feel slightly more sluggish off the line when fully loaded.

Numerically higher ratios (e.g., 3.70) are "shorter" or "steeper" gears. These are ideal for towing heavy loads or achieving rapid acceleration, as seen in the SRT trim. The higher ratio provides more leverage to get a heavy trailer moving. The trade-off is that the engine must spin at a higher RPM to maintain highway speeds, which increases fuel consumption and reduces overall MPG.

Common issues

The WK2 Grand Cherokee's driveline is generally quite reliable, but as mileage increases, a few known issues can arise with the differentials and axles:

• Ring and Pinion Whine: A high-pitched whining noise coming from the rear of the vehicle under light acceleration or deceleration usually points to worn pinion bearings or incorrect ring and pinion gear mesh.
• ELSD Motor Failures: Grand Cherokees equipped with Quadra-Drive II feature an Electronic Limited Slip Differential (ELSD) in the rear. The actuator motor for this system is exposed to the elements and can fail, resulting in a "Service 4WD" warning light and loss of limited-slip functionality.
• Carrier Bearing Wear: Vibrations felt through the floorboards at highway speeds can be indicative of a worn driveshaft center support bearing (carrier bearing).
• Limited-Slip Clutch Wear: If the vehicle shudders or chatters when taking tight corners, the internal clutches in the ELSD may be wearing out, or the differential fluid may require a friction modifier additive.

Find a driveline shop on Repairius to help you diagnose differential noise, perform fluid changes, or tackle gear ratio swaps to keep your Grand Cherokee running strong.