Sonnax Aisin AW 55-51SN Transmission

Valve Body (View Valve Body Layout Diagram)

B5 Control Spring 59947-33

Also fits AF23/33 and RE5F22A. Only some '05-later units were equipped with a control spring in the B5 clutch control valve lineup.

Helps cure:

Incorrect valve body calibration
Missing B5 control spring
2-3 Harsh
3-2 Harsh
2-3 Flare
3-2 Flare

LPC Accumulator Piston Kit 59947-LPC

Also fits AF23/33 and RE5F22A units.

Helps cure:

Low line pressure
Delayed Forward
Harsh shifts
2-3 Flare
Erratic SLT pressure

Lockup Control Valve Kit 59947-03K

Also fits AF23/33 and RE5F22A units.

Helps cure:

TCC apply & release concerns
Burnt converter
TCC codes

Lockup Relay Control Valve Kit 59947-01K

Also fits AF23/33 and RE5F22A units.

Helps cure:

TCC apply & release concerns
Inadequate lubrication
TCC codes

O-Ringed End Plug Kit 59947-21K

Also fits AF23/33 and RE5F22A units.

Helps cure:

Delayed Forward
Poor shift quality
TCC slip
3-2 Neutral
2-3 Flare
Low SLT pressure
Overheated fluid

Oversized B4 Release Valve Kit 59947-26K

Also fits AF23/33 and RE5F22A.

Helps cure:

2-3 Flare
2-3 Neutral
3-2 Harsh
3-2 Neutral

Tooling:

F-59947-TL26
VB-FIX

Oversized Lockup Control Valve & Boost Valve Kit 59947-29K

Also fits AF23/33 and RE5F22A units.

Helps cure:

Harsh downshifts
TCC apply & release concerns
RPM surge on coast
TCC codes
RPM surge on light acceleration
Overheated converter fluid

Tooling:

Oversized Lockup Relay Valve Kit 59947-77K

Also fits AF23/33 and RE5F22A.

Helps cure:

No lockup
TCC apply & release concerns
Delayed lockup
Burnt converter
Inadequate lubrication

Tooling:

F-97741-TL20
VB-FIX

Oversized Neutral Relay Valve Kit 59947-35K

Also fits AF23/33 and RE5F22A.

Helps cure:

Delayed Forward
Increased throttle required for engagement

Tooling:

F-59947-TL34
VB-FIX

Oversized Pressure Regulator & Boost Valve Kit 59947-12K

Also fits AF23/33 and RE5F22A.

Helps cure:

Soft shifts
Delayed shifts
Delayed engagement
TCC apply & release concerns
Harsh shifts

Tooling:

F-59947-TL12
VB-FIX

Oversized Secondary Regulator Valve Kit 59947-16K

Also fits AF23/33 and RE5F22A units.

Helps cure:

TCC slip
TCC surge
Overheated fluid, bushings & converter
Poor shift quality
Harsh Reverse
Low lube oil flow
Bushing failure

Tooling:

F-59947-TL16
VB-FIX

Oversized Solenoid Modulator Valve Kit 59947-34K

Also fits AF23/33 and RE5F22A.

Helps cure:

Low line pressure
2-3 Flare
No 3rd
No 4th
No 5th
Delayed Forward
5th Gear only
No lockup

Tooling:

F-59947-TL34
VB-FIX

Shift Pressure Control Valve Kit 59947-38K

Also fits AF23/33 and RE5F22A.

Helps cure:

2-3 Harsh
3-4 Harsh
No 5th
4-5 Harsh
Low Reverse pressure
C2 Clutch burned
B1 Clutches burned
B2 Clutches burned
High line pressure in Reverse

Solenoid Relay Valve Kit 59947-05K

Also fits AF23/33 and RE5F22A units.

Helps cure:

No lockup
Shift concerns
Engine stall on engagement
2-3 Flare
No 2-3
Harsh shifts
B5 Clutch distress

Solenoid Wire Connector Retainer 59947-60

Also fits AF23/33, RE5F22A, Volvo (AM6), Opel (AF40), Peugeot (TF80), Saab (AF40/6), Land Rover (TF80), Ford (AF21), Mazda (AW6A-EL).

Helps cure:

Broken solenoid connector

Zip Kit® AW55-50SN-ZIP

Also fits AF 23/33 and RE5F22A units.

Helps cure:

Burnt clutches
Delayed engagement
Inadequate lubrication
Low pressure
Slips & flares
Soft shifts
TCC apply & release concerns
TCC codes

Other

Tool Kit F-59947-TL26

Tooling:

VB-FIX

Tool Kit F-59947-TL34

Tooling:

VB-FIX

Tool Kit F-97741-TL20

Tooling:

VB-FIX

Tool Kit F-59947-TL16

Tooling:

VB-FIX

Tech Resources

January 25, 2023

Uncovering the Root Cause of Pressure & Complaints – The Critical Role of Solenoid Modulator & AFL Valves

Maura Stafford

July 01, 2020

Always Identify These Valve Bodies BEFORE You Start a Transmission Rebuild

Andrew Jessiman

April 21, 2015

Adapt & Overcome: Considering Control Module Adaptation During Diagnosis & Repair

Brian Wing

December 22, 2014

Aisin AW 55-50SN, 55-51SN, AF 23/33, RE5F22A Vacuum Test Guide

December 12, 2014

Aisin AW 55-50SN, 55-51SN Valve Body Layout

July 08, 2014

Transmission Report: Hit a Home Run Against 55-50/51SN Problems

January 01, 2013

Volvo 55-50/51SN Electronic Functions

January 01, 2013

55-50/51SN Valve Body Identification

January 01, 2013

Nissan 55-50/51SN Electronic Functions

January 01, 2013

Aisin AW 55-50/51SN Pressure Tap Locations

January 01, 2013

Saab 55-50/51SN Electronic Functions

January 01, 2013

GM/Saturn 55-50/51SN Electronic Functions

January 01, 2013

55-50/51SN Solenoid & Bracket Identification

January 22, 2011

Aisin AW Linear Solenoids

Bob Warnke

October 22, 2010

Manual Valve Confusion

Jeff Parlee

August 24, 2010

A Box, in a CAN

Serge Martin

April 30, 2010

AW 55-50 No Reverse & VW 09G No Move

Jeff Parlee

January 26, 2009

AW 55-50SN: Join the Club

Bob Warnke

October 28, 2008

Troubleshooting the AW 55-50SN Family

Bob Warnke

October 26, 2008

AW 55-50 / AF23-33: Diagnosis and Valve Body Information

Bob Warnke

July 31, 2008

AW 55-50 Differences Between Manufacturers - Part Two

Jeff Parlee

February 26, 2008

Adapting to the AW 55-50SN Valve Body

Bob Warnke