SK A4CF Reducing Regulator Repair
Fits: Hyundai/Kia models with A4CF1 or A4CF2
Requires Guide & Reamer Tool kit.
Prevents/Corrects/Reduces TransGo # A4A6-RV-TK
Brutal 6-4 kick-down bang, erratic shifting complaints,
flares/neutrals on shifts, gear ratio and/or solenoid
performance codes & delay engagements.
A4A6-RV-TK works on two different Transmission Families
A4CF 4-Speeds & A6MF 6-Speeds
Step 1
Disassemble Valve body and remove the Reducing Valve assembly Step 2 Reducing Regulator Bore Repair:
from the Lower Body. Save the retainer, adjuster & spring for re-use. Insert the reamer guide into reducing valve bore on the Lower Body.
Discard original valve. Use a 9/16 open end wrench on the flats of the reamer guide to keep
the guide from rotating. Insert the reamer into the guide.
Using lots of WD-40 and low speed on your favorite portable drill,
Lower Body shown assembled. let the reamer do the cutting until it bottoms in the bore.
Don’t force the reamer. Remove the tools and clean the body.
Re-use Discard original
reducing valve.
Lower Body
Reducing Valve
Location
Use Low Speed &
WD-40 works best.
Reamer
Guide
9/16 Wrench
08 Mar 2019 Page 1 © TransGo 2019
Step 1 Reducing Valve Measurement & Adjustment
Measurement Calculation
Do Not Skip This Step!
Measure stock adjustment: This is the gap between outside edge Original Gap= _________ Measure Original Gap first!
of spring seat and inside face of end plug. Add + .040" (We have seen them between .265-.340")
Write it down in the space provided. New Gap= _________
Now add .040. The result will be the new adjustment gap. Adjustment Bolt
Example: If original gap was .300", by adding .040" it would make
the New Gap .340". To adjust, hold the spring seat stationary (or
insert in VB) and turn adjustment bolt until gap measures .340". Spring
This step is necessary to work with the new larger valve. Seat
End Plug
Lower Body
Step 2 Install New Reducing Valve
With the lower body & new valve cleaned
& oiled, check for free movement and then
install the original spring, adjuster and
retainer. Step 3 Converter Limit Repair
Repair Converter Limit by removing & discarding the
Re-use Re-use original limit valve, spring and end plug. Save retainer!
Re-use Install New Discard Original Parts Re-use
Reducing Valve
Provided
Install the NEW Bushing, Valve, White Spring & Hol-
low End Plug followed by the original retainer.
Re-use
Hollow End faces Spring
New
New Bushing New Valve White New End
Spring Plug
08 Mar 2019 Page 2 © TransGo 2019
Additional Information
Alignment & Assembly
Lower Body
Lower Body
Dampener
Plate
N-R Control
Low Rev/OD Switching
Reducing Pressure
EPC Solenoid (Not Shown)
Pressure Regulator
Failsafe “B”
TCC Limit
Failsafe “A”
Install small plate on Use 2 15/64 (letter A) drill shanks
to the lower body. to align plate to lower body
then tighten plate bolt.
This is a typical parts layout of a A4CF1 Valve body. Your Valve Body
model may be different! Always mark the location of each of the small
parts and return them to their original locations! Due to the variety of
models and applications, expect differences and use care when
disassembling.
Lower Body & Plate
08 Mar 2019 Page 3 © TransGo 2019
Additional Information
Alignment & Assembly
Hollow Channel
End Plug Casting
Plate
Pressure Dampener
Ctrl A Clutch Ctrl
3 Weak Springs Alignment
first then a ball Hole
on each spring.
Use 2 15/64 (letter A)
drill shanks to align
Alignment plate to upper body
Hole then tighten plate bolt.
Upper Body
Pressure Pressure
Ctrl B Ctrl C
Install large plate on to the upper body.
08 Mar 2019 Page 4 © TransGo 2019
Additional Information
Alignment & Assembly Ball
1 Strong Spring
Filter Lower Body & Plate
(Previously Assembled)
Ball
Flip assembled lower body onto
Install channel casting over drill bits to align drill bits to align lower body with
with upper body & large plate. Install small channel casting. Install all bolts
parts into bottom side of channel casting. except “S” (solenoid body) bolts.
Flip body over and Install
Solenoid Body Plate, Body,
Lower Body Bolts at “S” locations & the Upper Body
Assembled wiring harness. Assembled
(Bottom Side) (Top Side)
S S
S S
S S
08 Mar 2019 Page 5 © TransGo 2019
Additional Information
Approx 3.5 Ω
EPC VFS
Lower Body
Upper Body
All sol’s this side (Bottom Side)
(Top Side)
approx 3.2 Ω
OD/LR PCSV-A
OD/LR Switch
TCC PCSV-D
2-4 PCSV-B
UD PCSV-C
All Sol’s are the same except for EPC VFS.
OD/LR Switch Sol (Labeled in some books as On/Off) is in fact NOT an on/off Watch for failed solder joints on harness connector.
Solenoid. It is PWM controlled like the rest. Function is to position LR/OD Back of pass-through case connector shown.
switch valve to direct OD/LR sol oil to proper circuit depending on whether Very common source of electrical codes.
OD or LR clutch is asked to be on. Solenoids are sequentially numbered but
are interchangeable. Failed Solder
Joint
® For the latest product release information, product part
numbers & distributor listings, log onto www.transgo.com.
Have a Great Day!
Mr. Shift
08 Mar 2019 Page 6 © TransGo 2019
