Chrysler 47RH & 47RE

47RH/47RE Transmission Specs & Ratios

The 47RH and later 47RE automatic transmissions are found in 1994 to 2003 model year Dodge Ram pickups. The 47RH was developed based on the 46RH, but with many improvements and revisions that rendered the transmission suitable for Cummins turbodiesel applications. The transmission, which is derived from Chrysler's TorqueFlite automatic transmission platform, features a relatively low input torque capacity considering its diesel applications. As such, model year 1994 through 2000 pickups equipped with the 47RH/47RE automatic transmission and Cummins Turbodiesel were slightly derated from the power ratings offered with a manual transmission.

47RH vs 47RE

The fundamental difference between the 47RH and 47RE is in the governor pressure control. Both units rely on a hydraulic valve body and electronically controlled overdrive unit. However, the governor pressure on the "RH" is hydraulically controlled, while the governor pressure on the "RE" is electronically controlled. The "H" and "E" are often misinterpreted as identifying the "RH" as an entirely hydraulically controlled and the "RE" as an entirely electronically controlled transmission - this is not exactly true as the 47RE retains a hydraulic valvebody.

The 47RE was offered briefly during the 2003 model year as the more desirable 48RE was being introduced behind the High Output Cummins variant. If the 8th digit of the vehicle identification number (VIN) is a "6", the engine is a standard output model and the transmission is a 47RE. If the 8th digit of the VIN is a "C", the engine is a high output model and the transmission is the stronger 48RE.

47RH & 47RE Gear Ratios

1st

2nd

3rd

4th

R

2.45 : 1

1.45 : 1

1.00 : 1

0.69 : 1

2.21 : 1

 

47RH & 47RE Transmission Specs

Transmission:

Chrysler 47RE

Type:

4 speed automatic OD transmission

Model Years/Applications:

1994 - 2003 Dodge Ram 2500/3500

Case Material:

Aluminum

Max Input Torque:

~ 450 lb-ft

Max GCWR:

19,000 lbs

Weight:

~ 200 lbs dry, w/out torque converter

ATF Type/Spec:

ATF+4 automatic transmission fluid

Service Intervals:

Fluid replacement, filter replacement, and band adjustment every 24,000 miles or 24 months (whichever comes first)

Features:

• Torque converter lockup (previously unavailable on diesel models)

• 47RH - 4 speed, strength designation "7", rear wheel drive, hydraulically controlled governor pressure

• 47RE - 4 speed, strength designation "7", rear wheel drive, electronically controlled governor pressure

 

47RH/47RE Reliability Concerns & Skepticism

The 47RH and 47RE transmissions are not often praised for their strength and reliability in Cummins turbodiesel applications. On the contrary, the reliability of the transmission in such a high torque application is questionable considering the Cummins' relatively high torque output and transmission's relatively low max input torque rating and GCWR. The 47RH/RE have a Chrysler strength designation of "7", which is based on a scale of 1 to 9 where 1 represents the weakest and 9 represents the strongest. The consensus is that this translates into a max input torque rating in the ballpark of 450 lb-ft; just above the 2000 and earlier model year Cummins and just below the 2001 - 2003 model year engine output.

Though the transmission sufficed, transmission reliability became a considerable concern for Dodge/Cummins owners, particularly those who towed with their vehicle. As the diesel performance industry boomed in the early 2000's, instances of problems and outright failures grew exponentially as people quickly came to realize the transmission's breaking point once modifying an engine for greater performance. The aftermarket has since responded and the 47RH and 47RE can be built to withstand tremendous stress. Regular maintenance, which is often neglected, is necessary to get the most out of the 47RH/RE. This includes replacing the transmission fluid, filter, and adjusting the bands at 24,000 mile intervals. Failure to adjust the bands per Dodge's recommendations will ultimately reduce the life the transmission as the clutch packs are likely to wear more rapidly.