TASC Force Tips
- Subject: Differences in valve-body designs
- Unit: Nissan RE5R05A
- Vehicle Applications: Infiniti, Nissan
- Essential Reading: Rebuilder, Diagnostician
- Author: Jeff Parlee
This transmission has been on the street since 2002, when it was first used in the Infiniti Q45 with the 4.5-liter engine. Since then, Infiniti and Nissan have used this transmission in many models. There are three versions of the RE5R05A valve body (Figure 1).
- The first design has two neutral-to-reverse accumulators on the lower body, behind the manual valve, and an empty valve bore under the low coast solenoid.
- The second design has the same two neutral-to-reverse accumulators, but there is a reverse-brake pressure-control valve where the empty bore was.
- The third design has one large neutral-to-reverse accumulator.
These valve-body designs should not be interchanged.
In addition to the three design levels, Infiniti used a low-resistance (10-15 ohms) low coast solenoid until August 2005 (Figure 2). After August 2005, Infiniti used the same high-resistance solenoid (20-40 ohms) that has always been used by Nissan. To complicate matters, Bosch, Nachi and Mitsubishi have all manufactured low coast solenoids for this transmission. Solenoids of different manufacture can be interchanged as long as their resistance matches.
Not all RE5R05A valve bodies have a cooler bypass valve. I have seen the cooler-bypass-valve bore empty on all three versions of this valve body. When the bore is empty, the separator plate will be closed off above the cooler-bypass-valve bore (figures 3 and 4).
Beware of the cooler!
About half of the cores we receive have water intrusion from failed coolers in the radiator. If the cooler has not failed on the unit you are working on, it is a good idea to replace it. It is only a matter of time before one will fail and damage your fresh transmission.
Jeff Parlee is director of product support at ValveBody Xpress and a member of the Sonnax TASC Force (Technical Automotive Specialties Committee), a group of recognized industry technical specialists, transmission rebuilders and Sonnax Industries Inc. technicians. ©2009 Sonnax Industries