MAZDA/FORD GF4A-EL/GF4EAT HARSH UPSHIFTS

COMPLAINT: 1993 & up, vehicles equipped with GF4A-EL transaxles, built before 1/3/95, may exhibit a harsh 1-2 upshift or harsh upshift complaints before or after overhaul. Line pressure appears to be normal or slightly higher than normal when checking in the "D" range. "Normal" line pressure readings are as follows, 60-78psi. at idle and 161-172 psi. at stall.

CAUSE: The cause may be, higher than normal control pressure passing through the main control spacer plate.

CORRECTION: Replace the Pressure Control Solenoid as shown in Figure 1 with Ford part number F32Z-7G136-AA or Mazda part number FU9A-21-1G1A. Inspect the Pressure Regulator Valve and the Pressure Regulator Valve bore for  wear or scoring. Inspect the Boost Valve and Boost Valve Sleeve for wear or scoring. Ensure that there is no "side to side" wobble of the Pressure Regulator Valve, when it is in its bore.See Figure 2. Enlarge the Pressure Regulator "balance" orifice in the rear control spacer plate to .056" as shown in Figure 3.

SERVICE INFORMATION:
PRESSURE CONTROL SOLENOID (FORD)........................................F32Z-7G136-AA
PRESSURE CONTROL SOLENOID (MAZDA).....................................FU9A-21-1G1A
NOTE: THESE TWO PART NUMBERS ARE FOR THE SAME SOLENOID.
 


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