July 01, 2020
Always Identify These Valve Bodies BEFORE You Start a Transmission Rebuild
Andrew Jessiman
55-50/51SN Valve Body Identification
The transaxle is manufactured by Aisin Warner, but is used by many car makers. Volvo calls it an AW55-50, Nissan and Infiniti call it an RE5F22A, GM (Chevy, Saab, Saturn and Pontiac) calls it an AF33-5.
Part Number Chart
| Vehicle Type | Early/Late | Has B5 Spring | Part Number |
|---|---|---|---|
| GM/Saab/Saturn/Suzuki | Early | No | AW55GE |
| GM/Saab/Saturn/Suzuki | Late | No | AW55GL |
| GM/Saab/Saturn/Suzuki | Late | Yes | AW55GMLSP |
| Volvo | Early | No | AW55VE |
| Volvo/Nissan | Late | No | AW55VL |
| Volvo/Nissan | Late | Yes | AW55NL |
Identify Vehicle Type
If vehicle type is not known check the S2 solenoid. A domed top on the S2 is a GM/Saab/Saturn/Suzuki. A flat top with four ribs radiating from the hole in the center of the S2 is a Nissan/Volvo.
| GM/Saab/Saturn/Suzuki | Volvo/Nissan |
|---|---|
 |  |
Identify Early/Late
Look for a letter cast into the valve body to the right of the S4 solenoid hold-down bolt.- "No Letter/Blank Space" and valve bodies cast with a letter "A" are considered early.
- Valve bodies cast with a letter "B" or "C" are considered late.
Check for B5 Spring
In model years '05-later, all Nissan and most GM/Volvo valve bodies may have a spring under the B5 control valve. It is very important to check the 10th digit of the VIN to verify production year. If the 10th digit of the VIN is 5 or higher, check your original valve body for a B5 control valve spring as shown. CAUTION: The wrong valve body will cause shift quality concerns.
Remove the two-bolt end plate as shown here and check under the B5 control valve to see if there is a spring.
| Spring | No Spring |
|---|---|
 |  |
Learn More
Related Units
Related Parts
Required
Recommended
55-50SN, 55-51SN
Remanufactured Valve Body AW55GE
GM, Early, “A” or No Letter Casting. Also fits AF23/33 units.
Required
Recommended
55-50SN, 55-51SN
Remanufactured Valve Body AW55GL
GM, Late, “B” or “C” Casting, without B5 Spring. Also fits AF23/33 units.
Required
Recommended
55-50SN, 55-51SN
Remanufactured Valve Body AW55GMLSP
GM, ’05-Later, with B5 Spring. Also fits AF23/33 units.
Required
Recommended
55-50SN, 55-51SN
Remanufactured Valve Body AW55NL
Volvo/Nissan, ’05-Later, with B5 Spring. Also fits RE5F22A units.
Required
Recommended
55-50SN, 55-51SN
Remanufactured Valve Body AW55VE
Volvo, Early, “A” or No Letter Casting, without B5 Spring. Also fits RE5F22A units.
Required
Recommended
55-50SN, 55-51SN
Remanufactured Valve Body AW55VL
Volvo/Nissan, Late, “B” or “C” Casting, without B5 Spring. Also fits RE5F22A units.
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