Prius 2002 crunking sound when accelerating or braking

I hv a toyota prius 2002 which hv been working fine bt has developed a mechanical problem which the mechanic is unable to fix yet. The car is producing a crunking sound after starting n hard accelerating n then of late when breaking also or when going uphill its like producing that sound continuously unless u light press the gas which means u will be very slow. It's like there are some gears or something that is "jumping" or has won out when the car requires power to accelerate hence the sound

The mechanic hv suggested replacing the gearbox.


I also hv done some research abt the issue n I think maybe it's the motor generator 2 inside the gearbox that might be hvg an issue.. Kindly advice if you can assist in resolving this issue

Thanks in advance

 

Yes I already have changed the cv joints and the left side front shaft bt still the crunking sound is still there

He did a full diagnosis and there was no error code

 

Will record the sound and post here

 

Will do another scan with a different person n post if there will be any error code. Of late it has turned on the master warning light though