October 27, 2014
GM and BMW 6L45 through 6L90 early- and late-style units cannot be interchanged but are very similar in appearance. Reference the Sonnax identification guide to verify the correct valve body is installed.
Sonnax remanufactured valve body GM6L80L has been designed to address common issues, such as: burnt clutches; codes P0751, P0741, P0742; harsh TCC apply; bump, harsh or flare shifts; bind-ups; solenoid performance codes; and wrong gear starts.
To guarantee the highest level of operational performance, this remanufactured valve body is tested on state-of-the art equipment to verify that actuator feed limit pressure, clutch pressures, torque converter pressures and compensator feed pressures match OE specification.
A TEHCM is not included with the valve body, but is available from OE and various aftermarket sources if required. A common fault with the TEHCM is failed pressure switches, which can be easily checked and repaired using Sonnax kits [124740-28K] or [124740-30K], if required.
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.