September 30, 2005
Anatomy of a Transmission: Oil Flow in the Pump-PR-Converter-Cooler Lube Circuits
Gregg Nader
In Toyota A340E/H Early (Type 1) units (Figure 1), the secondary pressure regulator valve receives regulated line fluid pressure from the main pressure regulator valve and routes it to the converter and lubrication circuits. The continual oscillation of the steel valve within the cast aluminum sleeve creates wear, allowing this valuable fluid pressure to exhaust and resulting in converter complaints, burnt apply components and lube-related failures. Sonnax oversized secondary pressure regulator valve kit 97741-17K restores proper hydraulic clearance and includes an O-ringed end plug to positively seal the balance pressure circuit.
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.
September 30, 2005
Gregg Nader
January 16, 2014
March 26, 2019
Jim Dial
Vacuum tests at the ports indicated fail to hold at least 18 in-Hg, or if visual wear is detected in the bore (Figure 2).