September 30, 2005
Required tool kit 74846-TL5 is no longer in production. Check with your distributor for availability.
Mazda vehicles with a G4A-EL, G4A-HL or GF4A-EL transmission may have problems with low line pressure, high line pressure, harsh shifts, lack of cooler flow, and/or blued converters. Many times these complaints can be traced back to a worn valve body bore at the pressure regulator valve.
If line balance or cutback feed pressure is allowed to leak, the valve can't regulate line pressure, so pressures remain high. TV balance pressure reduces line pressure in 2nd, 3rd and 4th Gears, so leaks at these spool diameters can cause harsh shifts. If the bore is worn at the line pressure passage, valuable line pressure may exhaust to sump.
Sonnax oversized pressure regulator valve 74846-05 for the these applications eliminates leakage of both balance oil and line pressure. The spring seat on the valve has been modified to compensate for the oversized valve and also provides higher line pressure at idle
Must measure OE valve small diameter before reaming. OE must be .357" It is highly recommended that the pressure modifier valve bore be checked for wear on the GF4A-EL unit as well. Sonnax offers an oversized pressure modifier valve, 74846-04, which can be used to refurbish bore wear at this location.
A vacuum test at the port indicated fails to hold at least 16 in-Hg.