Differential: V1 vs. V2

[sapote]

Why did the factory change to V2 diff? Based on my analysis, it's purely for manufacturability to save cost on labor.

V1: There is no simple way to set the LSD clutch slippage threshold but to select the correct clutch shim thickness (the last plate installed before the pump). The nature of clutch material makes it impossible to have a precise clutch pack thickness to achieve a certain clutch slippage threshold and so different shim is needed per unit. It would be a time consuming task to select the correct shim thickness for a specific slippage torque.

V2: This new version allows the Tech to adjust the clutch stack slippage by turning the lock ring -- tightening to increase and loosening to decrease -- then lock the ring with a dowel pin (a round ball was used instead in this case then ). So easy for the factory compared to adjust the shim in the V1 units. (The locking ring has left hand threads: CCW to tighten.)

[maw1124]

I’m loving the reverse engineering thought the last couple days (and years) to keep us on track. Thanks Sapote. I’ll likely never use any of it but it’s good to know. And I know most here will actually use it.

maw

[heinzboehmer]

I assumed the change was so they could share parts with the E9x M3/E60 M5. Presumably the design change was so the clutch pack can hold more torque.

[sapote]

Presumably the design change was so the clutch pack can hold more torque.

This is what I also assumed before, but to add more clutch plates for more torque, they just need to lengthen the V1 body instead of totally change the design using the locking ring on V2. Note that all the spider gears are still the same size as V1.