July 24, 2018
|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.
I work on transmissions for a living.
I work on other people’s vehicles for a living.
I am interested in enhancing my vehicle’s performance.
I work on my own vehicle(s) only.
None of the above categories describe me.
While Sonnax makes every effort to ensure the accuracy of technical articles at time of publication, we assume no liability for inaccuracies or for information which may become outdated or obsolete over time.