BACK
Technical Service Information
MAZDA/FORD GF4A-EL/GF4EAT
HARSH UPSHIFTS
COMPLAINT: 1993 & up, vehicles equipped with GF4A-EL transaxles, may exhibit a harsh 1-2 upshift or
harsh upshift complaints when "hot", before or after overhaul. Line pressure appears to be
normal or slightly higher than normal 60-70 psi. at idle and 161-172 psi. at stall when
checking in the "D" range when the vehicle is "cold." Although when the vehicle gets "hot"
the pressures get irratic and or exceed the stall pressure specs, which are 175 psi. in "D" and
300 psi. in "Reverse."
CAUSE: The cause may be, a faulty Pressure Control Solenoid, a worn Boost Valve and Sleeve and/or
a worn Pressure Regulator Valve bore which is part of the Rear Control Valve Body.
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 as shown in Figure 2. If the bore
has "shiny" spots where the Valve rides a "New" Rear Control Valve Body can be purchased
from Mazda. Inspect the Boost Valve and Boost Valve Sleeve for wear or scoring, and
replace as needed with Sonnax boost valve and sleeve as shown in Figure 2.
SERVICE INFORMATION:
Pressure Control Solenoid (Ford Part No.)..............................................F32Z-7G136-AA
Pressure Control Solenoid (Mazda Part No.).............................................FU9A-21-1G1A
Rear Control Valve Body (Mazda Part No.)................................................FU9C-21-115G
NOTE: This is a new casting with no valves in it.
Boost Valve and Sleeve (Sonnax Part No.)........................................................74846-01K
PRESSURE CONTROL
SOLENOID
FORD PART NO.
F32Z-7G136-AA
MAZDA PART NO.
FU9A-21-1G1A
NOTE: These Part Numbers
Are For The Same Solenoid.
Copyright © 2000 ATSG
Figure 1
00-43
AUTOMATIC TRANSMISSION SERVICE GROUP Page 1 of 2
BACK
Technical Service Information
REAR CONTROL VALVE BODY
SCREENS
CHECKBALLS
New Casting
INSPECT PRESSURE REGULATOR Available from Mazda
VALVE AND BORE FOR WEAR Part No. FU9C-21-115G
OR SIDE TO SIDE "WOBBLE"
PRESSURE REGULATOR VALVE
PRESSURE REGULATOR
VALVE SPRING
PRESSURE REGULATOR
VALVE SPRING SEAT
BOOST VALVE
BOOST VALVE Available from Sonnax
SLEEVE Part No. 74846-01K
INSPECT BOOST VALVE AND BOOST VALVE SLEEVE FOR
WEAR OR SIDE TO SIDE "WOBBLE"
Copyright © 2000 ATSG
Figure 2
00-43
AUTOMATIC TRANSMISSION SERVICE GROUP Page 2 of 2
