BMW gearbox: Splines and other information

Easily compare BMW gearboxes with each other

1. What do the letters mean?
2. BMW gearbox numbers

What do the letters mean?

What is the difference between the different letters / designations HGD / JGA / HGU / JGG?

• HGD / JGA
  These gearboxes have a "regular" input shaft located in a support bearing in the flywheel.
• HGU
  These gearboxes have a hole in the input shaft so an adapter is required between the support bearing and the input shaft. An adapter is used so that the input shaft of the gearbox will be supported / fit in the support bearing in the flywheel.
• HGA
  These gearboxes have the same input shaft as the HGD but with a different bell housing (Old BMW M50 style)
• JGG
  This gearbox comes from the BMW 123d.

BMW gearbox numbers

• GS6-53DZ = 26x35mm
• GS6-53BZ = 26x35mm
• GS5-39DZ = 10x35mm
• GS6-37DZ = 22x29mm
• GS6-37BZ = 22x29mm
• Getrag 420 TBAI = 10x35mm
• S5D-310 ZF-310 = 10x29mm
• S5D-250 = 10x29mm
• S5D-320 ZF-320 = 10x29mm
• Getrag 420 TBAB = 10x29mm
• GS7D36SG = DCT / DKG
• 8HP70