Excellent read!
So how come gear 2-3 is so "rough" if it doesn't involve the dog clutches? That's the only gear shift I find that is not very smooth while all other 8 gear changes are pretty smooth overall.
I should have read the C&D link geokilla posted. It answered why they didn't use the ZF 8HP. ZF 9HP was designed for transverse mounted engines like the one found in the TLX vs the ZF 8HP designed for longitudinal mounted engines commonly found in RWD BMW's.I just read that website as well. Didn't know the ZF 9HP had such a problem. Kind of shocked to see that the ratios are like that, having 5th as the 1:1 ratio instead of 6th. Why bother making a 9 speed automatic if we can't utilize it to the full potential? I wonder why Honda didn't use the Aisian 8 speed automatic used by Volvo.
I'm trying to understand what the author wrote and I have an idea idea on how the automatic transmission works now. However that doesn't explain the rougher 2-3 upshift does it? Since 2-3 uses the traditional friction brake and clutch elements, whatever that is. That's the only rough shift I can feel. Everything else felt good I think? Also according to my friend, this means the ZF 9HP would never shift as smoothly or rapidly as the 8 speed DCT developed by Honda or Aisin 8 speed automatic for example?
Edit: Car and Driver Explores the ZF 9HP as well.
*jealous*Update:
My 2-3 shifts are almost GONE/Undetectable. I have been doing some 'bat out of ****' style driving a few times, and two long road trips.