2014 Ram 3500 Transmission & Axle Gear Ratios

Transmission gear ratios

The 2014 Ram 3500 offered two primary transmission choices: the 68RFE 6-speed automatic and the Aisin AS69RC 6-speed automatic. Both are robust units designed to handle the demands of heavy-duty truck work.

68RFE 6-Speed Automatic

Aisin AS69RC 6-Speed Automatic

Available axle ratios

Ram offered a selection of axle ratios for the 2014 3500, allowing buyers to tailor their truck for specific needs, whether it be maximizing towing capacity or optimizing fuel economy. The available ratios were primarily 3.42, 3.73, and 4.10.

How to identify your axle ratio

Identifying your Ram 3500's axle ratio is crucial for proper maintenance, parts ordering, and understanding your truck's capabilities. For 2014 Ram trucks, the most reliable way is often through the door-jamb RPO sticker or by inspecting the axle itself.

Door-jamb RPO Sticker (inside driver's door): Look for a white sticker on the driver's side door jamb. This sticker will list various RPO (Regular Production Option) codes. The axle ratio code will typically start with "DM" followed by a letter, such as DMJ (3.42), DML (3.73), or DMH (4.10). You may also find a three-digit code on the sticker that directly indicates the ratio.

Axle Tag: Some Ram trucks may have a metal tag attached to one of the differential cover bolts. This square or rectangular tag will have numbers stamped on it, including the gear ratio (e.g., "3.73"). However, these tags can become corroded or lost over time.

VIN Decoder: Many online VIN decoder tools can provide information about your truck's original build specifications, including the axle ratio. This can be a helpful alternative if the sticker or tag is illegible or missing.

Towing vs MPG impact

The choice of axle ratio has a direct and significant impact on your truck's towing performance and fuel economy.

• Numerically Lower Ratio (e.g., 3.42): A numerically lower axle ratio means the engine turns fewer times for each revolution of the wheels. This results in lower engine RPMs at highway speeds, leading to better fuel economy. However, it also means less mechanical advantage for towing, which can lead to the engine working harder, more frequent downshifts, and potentially reduced towing capacity, especially with heavy loads or in hilly terrain.

• Numerically Higher Ratio (e.g., 4.10): Conversely, a numerically higher axle ratio means the engine turns more times for each revolution of the wheels. This provides greater mechanical advantage, making it easier to start heavy loads and maintain speed while towing. The trade-off is higher engine RPMs at highway speeds, which typically translates to lower fuel economy. For dedicated heavy haulers, the improved towing performance often outweighs the MPG penalty.

• Balanced Ratio (e.g., 3.73): A 3.73 axle ratio often strikes a good balance between towing capability and fuel efficiency for many users. It provides a noticeable improvement in towing over a 3.42 while offering better fuel economy than a 4.10 ratio.

Common issues

While Ram heavy-duty axles are generally robust, like any mechanical component, they can experience issues.

• Ring & Pinion Whine: A persistent whining noise that changes with vehicle speed (and sometimes load) can indicate wear or improper setup of the ring and pinion gears. This often necessitates gear replacement and proper backlash adjustment.

• Carrier Bearing Wear: The carrier bearings support the differential carrier within the axle housing. Worn carrier bearings can produce a growling or rumbling noise, especially when turning or accelerating, and can lead to excessive play in the differential.

• Limited-Slip Clutch Wear: Many Ram 3500s are equipped with a limited-slip differential (LSD). Over time, the clutch packs within the LSD can wear out, leading to a loss of limited-slip function. Symptoms might include a single wheel spinning on slippery surfaces, chattering, or shuddering during turns.

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