Intermittent growling and harsh vibrations in neutral - ZR-1 Net Registry Forums

1991 Corvette ZR-1 · 09-26-2021

Hello all. Recently, I have noticed an extra prominent growling, chatter or vibration while in neutral. I can feel it through the gearshift lever pretty well when it happens. Does not seem to happen all the time and does not occur when coasting in neutral from speed. I have mainly noticed it 20 seconds or so after startup and it lasts for about 5 seconds. Just came back from a drive and was waiting for the garage door to come up with clutch in and it did it again. Happens if using the clutch for neutral or leaving the gearshift in neutral gate and idling. Does not appear to be a thing that happens when in gear and at speed.

If I had to guess, it is dual mass related. 1991 with almost 93K miles. I am wondering if anyone else has experienced this? I am aware of the normal growling from black tags but this is not the normal frequency. I am planning a fluid flush of the trans next week and now I am considering replacing the clutch hydraulics just for safe measure. I committed a cardinal sin and only replaced a failing clutch master two years ago and left an aftermarket cast iron slave in place.

09-26-2021	#1
1991 Corvette ZR-1 Join Date: Sep 2018 Location: Florida Posts: 304	Intermittent growling and harsh vibrations in neutral Hello all. Recently, I have noticed an extra prominent growling, chatter or vibration while in neutral. I can feel it through the gearshift lever pretty well when it happens. Does not seem to happen all the time and does not occur when coasting in neutral from speed. I have mainly noticed it 20 seconds or so after startup and it lasts for about 5 seconds. Just came back from a drive and was waiting for the garage door to come up with clutch in and it did it again. Happens if using the clutch for neutral or leaving the gearshift in neutral gate and idling. Does not appear to be a thing that happens when in gear and at speed. If I had to guess, it is dual mass related. 1991 with almost 93K miles. I am wondering if anyone else has experienced this? I am aware of the normal growling from black tags but this is not the normal frequency. I am planning a fluid flush of the trans next week and now I am considering replacing the clutch hydraulics just for safe measure. I committed a cardinal sin and only replaced a failing clutch master two years ago and left an aftermarket cast iron slave in place.