My 1999 E55 with the 722.6 transmision seems to start shifting at 3k rpms but jerks as it in gauges at 4k. I believe its only 2nd gear going into 3rd. Anyway its seems to be that gear only. This only happens when I press the accelerator to 50% or more. if I ease into the throttle I can get to 0-60 quicker and the transmission shifts fine. Its only when I floor it that this happens. The best way to describe it is that it feels like a turbo spooling up from 3k rpms and at 4k rpms it throws you back in your seat. Any help will be useful. I dont want to start throwing money at it.

Make sure the "S/W" switch next to the gear selector lever is set to "W". "S" causes more aggressive shifts I find.
Maybe this is off-track, but it's cheap and easy to try.
Good luck.

W is only for winter mode, do you really want to use W-mode in summer starting in 2nd gear?

What's weird is I've seen both answers. Some say it's about weather (winter v. summer). Others say it's "s"port.
All I know is mine is sure a lot more mellow shifting in W. When I Google around, I can find support for either.

You might try this too - not too sure if it'll help, but it's free and easy.
I also saw this comment further down in the comments FWIW -

Kevin Walker

I thought this was just the throttle response reset, TCM is reset via removing battery power for 10mins

S is for standard shifting in 1st. and W is for what slippery slope?