noise when shifting

[quick85nat]

just bought an 87 turbo t, when under part throttle i hear a noise like a ratteling right before a gear shift,to me it sounds like a main bearing like noise,but if the car is parked or in neutral i can revv the hell out of it and i hear no noise so am i looking at a loose flex plate? thanks all

 

[2quiktocare]

Check for a broken flex plate and also make sure you have no other external parts hitting against the trans when at a certain rpm.