The engine revs but the tachometer doesn't increase. That leads me to think there is a faulty crankshaft position sensor or a wiring issue related the engine control module. I'm not sure how that directly correlates with the transmission issue other than it is related to ECM.
If you look at the pic I attached, it shows that the crankshaft position sensor signals the ECM, which then signals the tachometer. It's done via CAN, which stands for computer area network. Since the CAN system is involved, you really should scan the can system Here is a video that explains it:
Is it possible for you to record the noise you hear and upload it for me to hear?
Monday, June 8th, 2020 AT 7:40 PM