User:Jakefriend9/Ram pickup

The transmissions are labeled using the first number indicating the number of gears (including overdrive), the second number is the capacity rating, and the last letter is if it is electronically (E) or Hydraulically (H) controlled.^[1] The 42RE + RH are both 4 speed automatic transmissions with identical gear ratios. This transmission came available in 1989 and it is paired with a 10.75 inch diameter torque converter. The RH is an electronic governor system that is rated as a medium duty transmission. The RE is a mechanical Hydraulic system that is considered for heavy duty use. Both transmissions are also used in the Dodge Dakota and Jeep Cherokee among other Chrysler models. Gear ratios in both transmissions are 2.74 to 1 for first gear, 1.54 to 1 for second gear, 1.00 to 1 for third gear and .69 to 1 for fourth gear. ^[2].

Both the 46RH and RE are a 4 speed automatic that was born from the A518 family. The A727 was replaced by the A518 family in the early 1990's. The 46RH was first to replace the A727 and was preceded by the 46RE. The improvement with both models included the overdrive being added. The difference in the two transmissions was the RH had a hydraulically controlled governor versus the computer controlled on the RE.

The 47RH was released first and was only used in the Ram 2500 and 35oo series trucks that were equipped with the V10 gasoline or 5.9 Cummins diesel engines. The transmission was able to produce 450 lb-ft of torque and was able to tow trailers up to 19,000 pounds. This transmission was rated to be the highest capacity in the one ton series of trucks produced by any manufacturer. The RH was a hydraulically operated 3 speed transmission with a hydraulically controlled overdrive gear. The RH was later replaced by the RE however it was by name only since they are both hydraulically controlled. ^[3]

Dodge used the non-intercooled B-series Cummins engine up until the 91.5 year model Ram pickups, when they added a single pass intercooler, changed the injectors, modified the Holset H1-C turbo and adjusted their horsepower and torque ratings of the newly revamped powerplant.

References: https://www.drivingline.com/articles/cummins-history-lesson-1-89-93-59l/