[dp.]

So today after a hard acceleration from standstill my 535 started knocking LOUD.At first I thought it was crank/rod knock,but it's VERY loud(pedestrians are literally turning towards the car because they can hear it) and I've managed to drive the car at least 10 miles to my destination.What leads me to believe that this is a transmission problem (torque converter/backing plate related) are the following symptoms :
-engine runs normal,no power loss or anything
-oil was changed and inspected 700kms ago,couldn't find any metal particles in it.
-knocking noise goes away on partial throttle and on low revs near idle (not typical for a crank bearing failure).
-I've had a knocking noise before from time to time (a lot quieter though,like a bad hydraulic lifter quiet) and I've read that it's related to the torque convertor.Noise came and went unrelated to oil temp.
-from some time now car nearly always cranks very slow,like the engine is about to seize when warm/hot and when it starts there is always a grinding like sound(like someone's pulling out a saber),maybe this is backing plate related?
Absolutely no problem on undriven car though.
-Idle fluctuates when the ticking sound comes and this makes the car jerky when crawling.

So what do you guys think ? Since I'm about to remove the ZF and check things out,what should I look for on the TC/backing plate ?