This identification guide covers GM 6L45, 6L50, 6L80 and 6L90 valve bodies, plus the BMW early- and late-style transmission separator plates.
| 6L45/50 Early-Style ('10-Earlier) Upper Casting |
|---|
 |
| 6L45/50 Late-Style ('10-Later) Upper Casting |
|---|
 |
| 6L80 Early-Style ('10-Earlier) Upper Casting |
|---|
 Note: 6L90 Early-style ('10-earlier) also have the exhaust slots like shown above. |
| 6L90 Late-Style ('10-Later) Upper Casting |
|---|
 |
Look for machined-down boss (A, B, C or D) on the upper casting. Generally, if the A boss is machined down, this indicates an MYA/6L45 (see chart below). This identification system is not foolproof, as some valve bodies do not have any bosses machined down.
| Machined-Down Boss on Upper Valve Body | Indicates Valve Body Unit* |
| "A" Boss ID | MYA/6L45 |
| "B" Boss ID | MYB/6L50 |
| "C" Boss ID | MYC/6L80 |
| "D" Boss ID | MYD/6L90 |
| *Note: This is a general rule to follow, but may not always be true. Sometimes no bosses are machined. |
| 6L45-6L90 Early-Style ('10-Earlier) Lower Casting |
|---|
 |
| 6L45-6L90 Late-Style ('10-Later) Lower Casting |
|---|
 |
|
| Upper Casting Number | Center Support Feed Holes | Lower Casting Number |
|
| '10-Earlier | '10-Later | '10-Earlier | '10-Later |
| GM | 6L45 | 9405 | 7114 | Centered | 9581 | 0945 |
| 6L50 | 9405 | 7117 | Centered | 9581 | 0945 |
| 6L80 | 9404 | 0955 | Offset Front | 9581 | 0945 |
| 6L90 | 9404 | 0955 | Offset Rear | 9581 | 0945 |
| BMW | 6L45 | 1590 |
| Centered | 9581 or 6351 |
|
| BMW Early Separator Plate |
|---|
 |
| BMW Late Separator Plate |
|---|
 |
BMW early versus late applications have a separator plate variation in the converter circuit. At this time, there are no known year breaks or external identification features that can be provided.
