2017 Ram ProMaster Transmission & Axle Gear Ratios

Transmission gear ratios

The 2017 Ram ProMaster was offered with a single transmission option, the 62TE 6-speed automatic.

Available axle ratios

The 2017 Ram ProMaster offered a few axle ratio options, depending on the drivetrain and specific configuration.

How to identify your axle ratio

Identifying the axle ratio in your 2017 Ram ProMaster is crucial for proper maintenance, upgrades, or understanding its performance characteristics. Since Ram often shares common practices with other Stellantis brands, you'll typically find this information on a tag attached to the axle housing itself or on a build sticker within the vehicle.

Axle Tag

The most reliable way to find your axle ratio is to look for a metal tag affixed to one of the differential cover bolts on the rear axle housing. This tag will usually have the gear ratio stamped or printed on it. It might also include other information like the differential type (e.g., open, limited-slip).

Door-Jamb or Under-Hood Sticker

While not as consistently present for axle ratios as for tire pressures or paint codes, some Ram ProMaster models might have a build sticker on the driver's side door jamb or under the hood that lists RPO (Regular Production Option) codes. These codes are alphanumeric and correspond to specific vehicle features. Look for a code that starts with "DM" (e.g., DM2, DM3, DM4) as these typically denote axle ratios for Ram vans. If you find a sticker with many codes, you can usually cross-reference them with a Ram RPO decoder online or through a dealership service department.

VIN Decoder

Another method is to use a VIN decoder. Many online services and Ram dealerships can decode your vehicle's VIN (Vehicle Identification Number) to provide a comprehensive list of all original factory equipment, including the axle ratio. This is particularly useful if the physical tags or stickers are missing or unreadable.

Towing vs MPG impact

The choice of axle ratio significantly impacts your 2017 Ram ProMaster's performance, particularly regarding towing capability and fuel economy.

Numerically Lower Ratio (e.g., 3.86): A numerically lower axle ratio means the engine will operate at lower RPMs at a given road speed. This generally translates to better fuel economy, as the engine doesn't have to work as hard to maintain cruising speed. However, it will reduce the vehicle's pulling power, making it less suitable for heavy towing or hauling.

Numerically Higher Ratio (e.g., 4.07, 4.40): A numerically higher axle ratio means the engine will turn at higher RPMs for a given road speed. This provides more torque to the wheels, significantly improving towing and hauling capabilities. The downside is increased fuel consumption, as the engine is working harder and more revolutions per mile are required. For ProMaster owners who frequently carry heavy loads or tow trailers, a higher ratio is often a necessity, sacrificing some fuel efficiency for increased utility.

Common issues

While the 2017 Ram ProMaster is generally a robust workhorse, certain components can experience wear and tear over time. Regarding the driveline, owners might rarely encounter some issues, especially with high mileage or consistent heavy use.

Differential Whine or Howl

One of the more common complaints related to differentials is a persistent whine or howl, often heard at specific speeds or under certain load conditions. This can indicate wear in the ring and pinion gears, which are precisely machined to mesh correctly. If the backlash (the small gap between the gear teeth) is incorrect or if the gears themselves are worn or pitted, they can produce noise. Improper fluid levels or contaminated differential fluid can also contribute to this problem.

Carrier Bearing Wear

The carrier bearings support the differential carrier within the axle housing. Like any bearing, they can wear out over time, leading to noise (often a rumble or growl) and potentially excessive play in the driveline. This wear is often exacerbated by heavy loads, frequent towing, or insufficient lubrication.

Limited-Slip Clutch Wear (if equipped)

Some ProMaster models might be equipped with a limited-slip differential for improved traction. These differentials use clutches that can wear out over time, especially with aggressive driving or if the wrong type of differential fluid is used. Symptoms of worn limited-slip clutches can include chattering or shuddering noises during turns, or a decrease in traction in slippery conditions. It's crucial to use the specified friction modifier in the differential fluid if your ProMaster has a limited-slip differential.

Find a driveline shop on Repairius.