I couldnt find anything that described what I have just the usual clunk at changing gears typical of a bad mount.
I have an early 1971 Datsun 240z with a 4 speed manual built in 1/71. All original to my knowledge. Besides the clunk at accel and decel (front diff mount that is no longer in production) I also have a loud clunking/rattle when i let go of the gas over 60mph then goes away under 60mph. Sounds like somebody with 2 hammers hitting the bottom of the car rapidly. When I have it up on jack stands it does the same on 2nd and 4th gear at idle. its louder on the drivers side wheel for some reason.. Quieter without the wheels. when i hold the drivers side wheel and let the passenger side spin away (yes its an open diff) it still makes the same loud clank on the drivers same if i hold the passenger side wheel. still louder on the drivers side.. and also jerks at the wheel when holding it.. Bad Diff?