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|
|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.