September 30, 2005
In Jatco/Nissan RE5R05A units, the cooler bypass valve is designed to allow excess oil to bypass the cooler circuit when required. However, if there is excessive wear in the bore, it can allow converter and/or lube circuit leakage and prevent the valve from stroking to the bypass position if needed. This can result in increased ATF temperature causing bushing and sealing failure, planetary destruction and converter or part overheating and damage. Severe wear prevents the valve from stroking properly, simulating a cooler restriction and increasing converter charge pressure. Sonnax oversized cooler bypass valve kit 63741-07K allows the bore to be refurbished to restore hydraulic integrity and has multiple design improvements to prevent reoccurrence of the failure.
Some RE5R05A valve bodies do not contain a cooler bypass valve. Units can be identified by empty cooler bypass bore, blocked separator plate holes and separator plate code (Chart below). Do not install Sonnax product into units that do not require cooler bypass valve.
|Units with No Cooler Bypass Valve (Do NOT install this part)|
|Valve Body Design See link for identifcation guide||Separator Plate Code|
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.