GM & BMW 6L80 Family Identification Guide

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.