Generations of Dodge Ram w/Cummins Turbo Diesel¶

This, is a short post containing knowledge I gathered on the various generations of Dodge Ram trucks w/Cummins Turbo Diesels.

Generations¶

As a note, the power handling capabilities are sourced from random locations on the internet. Please take with a grain of salt.

Engine: 5.9L 12v Cummins
- Suffers KDP
  - A dowel pin inside of the timing case can potentially work itself loose over time, becoming lodged in the timing gears, causing potential rapid unscheduled engine disassembly.
  - Explanation From DieselHub.com
- Bolts used inside timing case, can also potentially become loose, and lodge into the timing gears. Preventive action involves removing the bolts, loctite, and re-torque.
- The rotating internals are capable of 700-800hp or more. Factory forged steel I-beam rods.
Lift Pump: Mechanical lift pump.
Mechanical Injection: Bosch VE Pump
- Can be modified to support 300-400hp, with basic modifications.
- Maximum potential is around 500hp.
Transmission: Getrag 5-speed manual
- Typically good for 500-600ft-lbs of torque
Emissions: None.

Engine: 5.9L 12v Cummins
- Suffers KDP
  - A dowel pin inside of the timing case can potentially work itself loose over time, becoming lodged in the timing gears, causing potential rapid unscheduled engine disassembly.
  - Explanation From DieselHub.com
- Bolts used inside timing case, can also potentially become loose, and lodge into the timing gears. Preventive action involves removing the bolts, loctite, and re-torque.
- The rotating internals are capable of 700-800hp or more. Factory forged steel I-beam rods.
Lift Pump: Mechanical lift pump.
Mechanical Injection: Bosch P-Pump
- This is the most desirable injection pump.
- These can be modified and built to support pretty extremely horsepower levels, in excess of 1,000hp.
- These are relatively easy to tune.
- Can support 700+ HP with simple modifications. 1,000+ is not unheard of with extensive mods.
Transmission: NV4500, 5 speed manual
- These have issues with 5th gear, with increased power. Will literally strip the teeth from the gears.
- 5th gear nut issue- There is a nut which will come loose over time, causing loss of 5th gear. Easily corrected.
- Typically handle 800-900ft-lbs of torque with a good clutch.
Emissions: None.

Midway through 1998, The Ram transitioned from the mechanical 12v, to an electronically injected 24v.

Engine: 5.9L 24v Cummins
- The rotating internals are capable of 700-800hp or more. Factory forged steel I-beam rods.
- Block 53 Issue
  - YouTube Explanation
  - TLDR; Engine blocks with "53" casting, are more prone to cracking under normal operating conditions, around the rear feeze plug due to a manufacturing defect.
Lift Pump: Electronic frame-mounted lift pump.
- These are a common point of issue.
Electrical Injection: Bosch VP44
- Failing lift pump will cause injection pump to fail.
- These are electrically tuned, rather then mechanically.
- 400-500hp potential. Limited by the design of the pump.
Transmission: NV5600, 6 speed manual
- These are supposedly much stouter then the NV4500
- 1,000-1,100 ft-lbs potential with good clutch.
Emissions: None.

The 3rd generation introduced common rail injection.

Engine: 5.9L 24v Cummins
- 700-800hp potential on stock internals. Factory forged steel rods.
Lift Pump: Electronic, In-tank pump.
Electrical Injection: Bosch CP3
- Significant upgrade over the VP44s, in terms of both reliably, and output.
- Stock pump can support up to 700hp with modifications. After this point, Dual CP3s is typically recommended.
Transmission:
- 2003-2004: NV5600, 6 speed manual
  - These are supposedly much stouter then the NV4500
  - 1,000-1,100 ft-lbs potential with good clutch.
- 2005-2007: G56, 6 speed manual
  - Weaker then NV5600s in stock form.
  - Cannot as easily be built for big power.
  - 900-1,000 ft-lb capable with good clutch.
Emissions: None.

Mid 2007, the 6.7L models were released, to comply with new emissions requirements.

The emissions hardware is a very common, and expensive failure point.

Engine: 6.7L 24v Cummins
- 600-700hp on stock internals. These years switched to powdered metal rods.
Lift Pump: Electronic, In-tank pump.
Electrical Injection: Bosch CP3
- Stock pump can support up to 700hp with modifications. After this point, Dual CP3s is typically recommended.
Transmission: G56, 6 speed manual
- Weaker then NV5600s in stock form.
- Cannot as easily be built for big power.
- 900-1,000 ft-lb capable with good clutch.
Emissions: DPF, EGR
- DPF is a common failure item. Expensive to replace or repair.

Engine: 6.7L 24v Cummins
- 600-700hp on stock internals. powdered Metal Rods.
Lift Pump: Electronic, In-tank pump.
Electrical Injection: Bosch CP3
- Stock pump can support up to 700hp with modifications. After this point, Dual CP3s is typically recommended.
Transmission: G56, 6 speed manual
- Weaker then NV5600s in stock form.
- Cannot as easily be built for big power.
- 900-1,000 ft-lb capable with good clutch.
Emissions: DPF, DEF, EGR
- DPF is a common failure item. Expensive to replace or repair.
- DEF was introduced in 2013.

No option for manual transmission. Not even considered.

In my opinion, The best years are either....

3rd Generation, 2003-2007: If you prefer electronic control.
- Can plug in a tuner, and voila. 400-500hp.
2nd Generation, 1994-1998: If you prefer mechanical control.
- Simple modifications to the P-Pump will easily have you around 300-400hp.

I would avoid...

2nd Generation, 1998.5-2002:
- The VP44 is the main drawback to this generation. It is the least desirable pump.
- Although- with a tuner-only, you can achieve around 300-400hp, without getting dirty and greasy.
- Lift pump should be replaced on these models. When it fails, it can cause the failure of the injection pump as well. $$$
Anything newer then 2007.5:
- The introduction of emissions hardware is a common reliability issue.
- These can be expensive to repair/replace.
- It is illegal to remove this hardware. The EPA has been known to throw the sledgehammer at shops willing to do this modification.