Many have had problems with jerking from the automatic transmission. There are many things that can cause it, there isn't one simple fix.

There is no angle sensor on the gearbox. If you have a problem on hills and bumps it is either because
a) you need to apply more torque to overcome the hill, and the shifting control isn't functioning properly (valve body and sensors)
b) the fluid level isn't correct and the transmission sees, in effect, a different fluid level when it is on an incline

Start with b, it is easier. Check the fluid level.

If that doesn't help, changing the fluid is not likely to have any effect. Do it if you like, on the basis that it is the second cheapest thing to do, but I wouldn't bother myself.

I would go to the valve body, and have that overhauled/replaced. You get new fluid along with that. I would do that before considering a teardown of the transmission, ie a full transmission overhaul. The valve body can be done without removing the transmission from the vehicle.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue