History of the Nissan RE4R01A and RE4R03A transmissions
Jatco, a subsidiary of Nissan that builds automatic transmissions, developed and released the Nissan RE4R01A and RE4R03A range of transmissions from 1988.
Based on the fully hydraulic RL4R transmission, the RE4R01A and RE4R03A are electronically controlled automatic transmissions which are used in a wide variety of Nissan, Mazda and Infiniti vehicles.
Since the RE4R01A and RE4R03A were released, they came in new vehicles for about 27 years until as recently as 2015. The RE4 is one of the most successful series of automatic transmissions ever made, and for many reasons as we will see.
Specifications of the RE4R01A and RE4R03A transmissions
The naming scheme reveals a bit about the transmission. The 4 in RE4 refers to the 4 forward gears, and 01A indicates this transmission has the lower relative strength compared to stronger 03A. This transmission was also seen in other vehicles, with different naming conventions such as the JR402E in Mazda vehicles.
The RE4R01A is rated as a light to medium duty transmission, capable of holding 300 to 400hp and up to 400 Nm of torque, and the RE4R03A is rated as medium to heavy duty transmission capable of holding 600 to 700hp and as much as 800 Nm of torque.
The RE4R01A is extensively used in sports cars and light pick-up trucks like the Nissan Pathfinder and Navara, while the RE4R03A is used in a wide variety of vehicles such as Nissan Patrol SUVs, commercial trucks and higher powered sports cars.
Both the transmissions are very similar in design, although the RE4R03A has been strengthened in many ways to include a bigger planetary gear, more clutch frictions per clutch pack and stronger internal components.
Both the transmissions have a solenoid-controlled valve body, a lockup torque converter clutch and have stayed pretty much the same since they were released. There were minor differences depending on the vehicle it was put in, such as varying lengths of input/output shifts for different vehicles and configurations. Some vehicles came with a manual overdrive button to engage 4th gear, while some had no overdrive button.
Gear Ratios of the RE4R01A and RE4R03A transmissions
RE4R01A / RE4R03A
Strengths of the RE4R01A and RE4R03A transmissions
The decades that the RE4 was in production is a testament to its quality. It is a very reliable and durable transmission that is used in SUVs like the Nissan Xterra and Nissan Patrol. The RE4R03A has proven to work excellently in towing heavy loads, off-road vehicles and high horsepower applications.
All the RE4 transmissions have a lock-up torque converter clutch (TCC) which provides a direct drive from the engine to the transmission. This helps reduce fuel consumption due to less slippage in the transmission, as well as reduces heat build-up. All this has a positive effect by reducing engine and transmission wear.
Being an electronically controlled transmission, a transmission control unit activates solenoids in the valve body to engage the gears at the right time, as well as lock up the TCC based on parameters such as engine speed, throttle position and transmission temperature.
The transmission control unit not only protects the transmission, but in case anything were to go wrong, problems can be easily diagnosed by viewing the generated trouble codes.
Weaknesses of the RE4R01A and RE4R03A transmissions
Soon after the RE4 was released in 1988, there were a lot of problems caused by the early torque converters. They were very unreliable, too small and inefficient. Jatco then made a lot of upgrades from 1988 to 1992 which resolved almost all the main problems seen in the early models.
Overheating is another issue that can severely degrade the RE4’s performance and reliability. Excess heat is usually caused by towing heavy loads and especially when the torque converter clutch doesn’t stay locked for long enough. The RE4R03A in the Nissan Y60 Patrol had known problems caused by excess heat. The stock transmission controller would unlock the TCC prematurely and would keep it unlocked for too long in situations such as going up a long hill. This caused huge heat build-up in the torque converter, causing the lining to degrade and block the transmission fluid filter, leading to transmission failure.
Custom vehicles which use the RE4R01A and RE4R03A transmissions
The RE4 transmission is very popular in the vehicle modification scene, especially with owners looking to convert their vehicle from a manual to automatic or those looking to do an engine upgrade.
The versatility of this transmission allows you to mix and match parts from the RE4R01A and the RE4R03A. You may use the internals of the stronger RE4R03A with the bellhousing, input and output shaft of a RE4R01A, say if you wanted it to hold more horsepower in a modified sports car.
Nissan owners often upgrade from a ZD30 engine to TD42 engine, but there have been countless examples of all sorts of engines mounted to the RE4 transmissions, such as the Toyota 1HD-FTE engines, BMW engines, Mercedes engines and various Cummins engines to name a few.
While adding aftermarket turbo kits and engine swaps are popular among enthusiasts, these modifications tend to cause a fair share of problems for owners, especially when it comes to smooth transmission operation. This is due to the fact that the stock transmission controller is programmed to work with a stock engine, whose power curve and characteristics could be completely different to a modified engine with an added turbo.
This is where it becomes absolutely essential to have a good, programmable transmission controller such as the COMPUSHIFT Sport.
The Nissan Patrol GU featured the RE4R03A since its release until 2015
The lighter RE4R01A transmission was more commonly seen in sports cars like the Nissan 300ZX (Commonly called Fairlady Z)
Controlling the RE4R01A and RE4R03A transmissions with the COMPUSHIFT
As the RE4 transmissions are fully electronic, they can be easily linked up and controlled with a COMPUSHIFT Sport transmission controller.
With the COMPUSHIFT Sport, you can monitor the transmission’s operation on the go, and you can adjust parameters such as shift points and also troubleshoot any issues, both electrical and mechanical via the accompanying mobile app over a Bluetooth connection.
You can also lock up the torque converter clutch anytime you wish, allowing you to save fuel by locking up earlier when cruising, or you can also make use of engine braking on downhill slopes by keeping the torque converter clutch locked. This helps save brake pads and is very helpful when towing heavy loads.
The COMPUSHIFT Sport is designed to work with various engines, both old and new. It is compatible and can also connect to most aftermarket engine control units (ECUs) including Haltech and Motec engine management systems via CAN bus, and if fitted with the AccuLink TPS sensors, the COMPUSHIFT Sport can also work with older carburetor engines.
To find out what you need to start controlling your Nissan RE4R01A or RE4R03A transmission with the COMPUSHIFT Sport, head on over to our configurator tool over here.
To get details on the COMPUSHIFT Nissan RE4R01A or RE4R03A transmission controller click the below link: