2020 Jeep Wrangler Transmission & Axle Gear Ratios

The 2020 Jeep Wrangler (JL generation) is a legendary off-roader, and its powertrain is a massive part of what makes it so capable on the trails and on the highway. Whether you are crawling over boulders in a Rubicon or commuting in a Sahara, understanding your transmission and axle gear ratios is crucial. The right gearing determines how your Wrangler delivers torque to the ground, impacts your fuel economy, and dictates your towing capacity.

Below is a comprehensive guide to the transmission and axle specifications for the 2020 Jeep Wrangler.

Transmission gear ratios

The 2020 Jeep Wrangler offers two primary transmission options: a 6-speed Aisin AL6 manual transmission (standard on most V6 models) and an 8-speed TorqueFlite automatic transmission (850RE for gas engines, and the heavy-duty 8HP75 for the EcoDiesel). The 8-speed automatic is renowned for its wide gear spread, offering an aggressive first gear for off-the-line torque and dual overdrive gears for highway efficiency.

6-Speed Manual (Aisin AL6)

8-Speed Automatic (TorqueFlite 850RE / 8HP75)

Available axle ratios

Jeep carefully pairs specific axle ratios to different trims and engine combinations to optimize performance. Rubicon models feature numerically higher gear ratios to compensate for larger standard tires and to maximize low-end crawl ratios, while Sport and Sahara models lean toward efficiency.

How to identify your axle ratio

If you are unsure which gear ratio your 2020 Jeep Wrangler is equipped with, there are several easy ways to find out:

1. Check the Window Sticker or Build Sheet: If you still have the original Monroney sticker, the axle ratio will be listed under standard equipment or optional packages (like the Max Tow package).
2. Axle Tag: Crawl underneath the rear of your Jeep and look at the differential cover. Jeep attaches a metal tag bolted directly to the differential housing. Look for a series of numbers that will explicitly state "3.45", "3.73", or "4.10".
3. VIN Decoder: Because Jeep doesn't typically use traditional GM-style door-jamb RPO codes, the easiest digital method is to enter your VIN into the official Mopar/Jeep owner's portal or a trusted VIN decoder. This will generate your Jeep's exact build sheet, showing the axle code (like DMF for 4.10s) and the specific Dana axle model (Dana 30, Dana 35, or Dana 44).

Towing vs MPG impact

Your axle ratio dictates the balance between your engine's RPMs at highway speeds and the amount of torque delivered to the wheels at low speeds.

Numerically lower ratios (e.g., 3.45): These are considered "taller" gears. A 3.45 gear ratio means the driveshaft turns 3.45 times for every single rotation of the tires. This keeps engine RPMs lower at highway speeds, resulting in noticeably better fuel economy (MPG). However, it limits low-end grunt, making acceleration feel slightly more sluggish with larger aftermarket tires and reducing your overall towing performance.

Numerically higher ratios (e.g., 4.10): These are "shorter" gears. They provide greater torque multiplication at the wheels. This is why the Rubicon, meant for conquering steep, rocky inclines, uses 4.10 gears. Higher numerical ratios are vastly superior for towing trailers and turning heavy, oversized mud-terrain tires. The trade-off is that your engine will spin at higher RPMs on the highway, negatively impacting your gas mileage.

Common issues

The 2020 Jeep Wrangler utilizes robust Dana axles (AdvanTEK Dana 30s and 44s for the JL generation). However, a few driveline issues are known to occur, particularly if the vehicle is pushed hard off-road or lifted improperly:

• Ring & pinion whine: Often resulting from improper gear mesh, low differential fluid, or heavy towing, a high-pitched whine under acceleration or deceleration can indicate ring and pinion wear.
• Limited-slip clutch wear: If your Wrangler is equipped with the Trac-Lok anti-spin rear differential (available on Sport and Sahara), the internal clutch packs naturally wear out over time. If you notice your rear tires spinning independently in mud or snow, or hear a chattering sound around tight corners, the clutch packs likely need replacement.
• Carrier bearing and axle seal leaks: Off-roading in deep water or mud can force debris past the axle seals, contaminating the gear oil. This can quickly lead to accelerated carrier bearing wear and eventual failure if the fluid isn't drained and replaced promptly.

If you suspect any differential issues, or if you are looking to re-gear your Wrangler for 35-inch or 37-inch tires, you should consult a professional. Find a driveline shop on Repairius.