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Thoroughbred Diesel has been your online performance headquarters since 2002. We know how to get the most performance out of your pickup truck and offer all of today's most popular diesel performance products.
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Diamond Eye Performance
Thoroughbred Sku #: ATS319904A326
Manufacturer Sku #: 319904A326
2007 - 2016 Dodge Ram 2500
2007 - 2016 Dodge Ram 3500
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The advantage of the 4R-Performance transmission over any Stock or performance
built 68-RFE is ultimate reliability and price. The 68-RFE transmission has
some great qualities but unfortunately it suffers in several areas that cannot
be easily overcome. Our performance built 68-RFE transmission with the Co-Pilot
installed is great at power levels up to about 600 RWHP, although we have several
trucks out there that are 900+ the 68-RFE is not the favored choice for that
power level. Here are a few conditions that we have a difficult time dealing
with when it comes to the 68-RFE "clutch to clutch" transmission.
First off the 68 clutch apply and release is 100% computer controlled. That
means every time a clutch pack is applied or released the computer must control
the exact clutch apply rate and the exact clutch release rate during the shift
with exact precision or one of the two clutch packs being applied and released
will be damaged. This is the real issue with the 68 transmission. There are
5 clutch packs in the 68 transmission that are responsible for all forward and
reverse gears. If two clutch packs are applied you get one of 6 forward gear
ratios, if one is applied you get no movement and if three are applied you get
a bind-up or clutch drag! It is just short of a miracle that the Dodge TCM can
adapt to such changing conditions that effect clutch to clutch application rates
as well as it does. Here are a few of these changing conditions, fluid temperature,
engine load, power level, throttle position, clutch coefficient, line pressure,
internal hydraulic leaks, internal clutch clearance, solenoid resistance, wiring
fatigue, corrosion, battery voltage, humidity, vibration, and the list goes
on and you get the point. This is all wrapped around the envelope that the engineers
calculated to be the environment that the 68 transmission would live in. This
is why the 68 is relatively reliable in a bone stock truck using factory stock
calibration. As soon as you increase power to the engine by installing a tuner
you go beyond the ability for the TCM to accurately calculate the clutch volume
index (CVI) of each clutch pack. CVIs are used by the TCM so it knows the clutch
pack clearance of each clutch pack. The TCM must know the clutch pack clearance
so it will know what CVI number to plug into its algorithm to accurately apply
and release the on and off going clutch pack. The TCM must do this correctly
every time under all power levels to ensure a consistent shift takes place.
Where the 68 gets into trouble, we deal with all this nonsense by placing the
Co-Pilot between the TCM and the transmission and apply another level of input
(True engine load) to the TCM and take control of the transmission. This allows
our Built 68-RFE to reliable and consistently handle up to 650 RWHP without
the negative effects as long as the rest of the factory electronics are in good
condition. As you can see 68 transmission is a slave to the outside environment
and is very venerable to so many possible problems that can and does often cause
total transmission failure in a very short time!
The 4R Advantage
First off, the 4R transmission is a synchronous type transmission which means
there is no "clutch to clutch" timing issues that need to be dealt
with by the computer! This in itself lay the foundation for a brutally reliable
transmission package! Shift quality is much better controlled by the 4R trans,
all shifts are actuated by an on/off shift solenoid that passes clutch application
through a clutch fill valve that also has an accumulator to better control clutch
fill time allowing for precise clutch application. This provides a near perfect
shift at all power levels. The gear ratios of the 4R Transmission are evenly
spaced providing a consistent RPM drop between all shifts. This consistent RPM
drop gives a smooth power transfer while reducing the air disturbance through
the turbocharger maintaining even boost levels. The Torque converter clutch
(TCC) application is a modern-day type Pulse Width Modulation (PWM) signal that
provides smooth controllable TCC application. All this combined adds up to a
transmission that shifts through all the gears and applies the TC with smooth
The specialty-built torque converter is custom manufactured to perfectly match
the exact stall speed of the Cummins torque curve to provide the optimal RPM
flash stall allowing the turbocharger to start making boost pressure while at
the lowest RPM range possible. This is all because of the properly designed
Turbine, Impeller and stator design. The billet stator directs fluid from the
impeller back into the turbine to most efficiently harness the lost energy in
the fluid that is not absorbed by the turbine. All this means the torque multiplication
is maximized providing a very smooth power transfer and maximum torque transfer
from the engine to the transmission at a RPM that is well within the beginning
of the torque curve of the engine. The lock up section of the converter is our
patented Viskus Clutch pack design that allows for a smooth transition from
fluid coupling to a 100% mechanical engagement providing over 3000-foot pounds
of torque transfer without slip! The overly built Viskus clutch pack allows
for a pulsed in TCC application at any power level without the concern of damage
to the clutch pack. What this means is the PWM application of the 4R-Performance
trans can be utilized in the programing to slowly apply the TCC providing a
soft application while not damaging the TCC. All this translates to an even
RPM drop any time the TCC clutch is applied. You will never again have to live
with a hard TCC shift.
The 4R-Trans has a superb gear ratio set that really favors the Diesel engine.
The gear ratio provides an even RPM drop between all shifts from 1st all that
way to 4th gear. This coupled with the ability to release and apply the TCC
between shifts gives the feeling of the smoothest power transfer at speeds up
to 100 MPH! Here are the Ratios of the 4R-Trans, 1st=2.71:1 2nd=1.54:1 3rd=1.00:1
Full synchronous shift
The synchronous shift application of the transmission means there are no "clutch
to clutch" timing concerns to deal with while making the transition between
gear shifts. The 68-RFE transmissions require a managed application rate to
apply a clutch while also having to manage the release of a clutch to achieve
a desired shift. All this overhead presents a real problem when adapting to
large power swings like a turbo charged diesel presents. This is the main reason
the 68 transmission has a serious issue coping with the power fluctuation levels
of the turbo charged Cummins. The 4R transmission clutch application only requires
a single feed to apply all four gear applications. The simplicity of the hydraulic
circuits and the synchronous operation provide a perfect performance transmission
The 4R has electronic line pressure control, electronic accumulator control
and PWM TCC control = All this allows the precision turning capability so the
user can not only control when each shift occurs and the converter clutch occurs
but the shift quality can be altered by changing line pressure along with tailoring
the accumulator rate to optimize shift quality throughout the entire power curve.
Not only can we tailor the shift quality but we can also tie the clutch application,
TCC apply and accumulator rate directly to engine load instead of only throttle
percentage! This equated to the best shifting transmission you have ever driven!
In general, the ATS 4R Performance transmission package is the perfect transmission
choice for just about any application. We offer a variety of mounting options
so the transmission can be placed behind just about any 5.9 or 6.7L Cummins
Engine. We have transmission internal build options from stock power to extreme
1500 HP+ applications. The transmission controller package is easy to install
and comes complete with all plug-n-play wiring harness, software and instructions.
We also have a full tech support team to answer any questions you have before,
during or after the 4R Transmission package is installed.
Note: Customers will be required to shorten/lengthen the front
and rear drive shafts for appropriate length, angle and fitment. Drive shafts
are not included. Customers are also required to replace the transfer case head
gear which is included in this kit.
Note: Kit includes components needed. Transmission is not
included and must be purchased separately.