Slight "rumble" over 50 mph '75 coupe
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Le Mans Master
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Slight "rumble" over 50 mph '75 coupe
The drive is smooth from Zero to 50 in any gear. While cruising at 50 the car is still okay, then I get a slight rumble (vibration) when I accelerate, but not while maintaining speed. This rumble/no rumble continues at higher speeds, also. Any ideas? Thank you
Last edited by cor66vette; Sep 17, 2017 at 03:11 PM. Reason: added vibration
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From: Charlotte NC
All I can suggest is that all components of your driveline need to be inspected.
So...transmission mount, rear differential mounts and so on. Anything that will move when under a load (acceleration) and then lessen when you are sustaining a constant speed.
DUB
So...transmission mount, rear differential mounts and so on. Anything that will move when under a load (acceleration) and then lessen when you are sustaining a constant speed.
DUB
Thread Starter
Le Mans Master
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DUB
Thanks. Might there be anything specific I should concentrate on considering this happens at 50 mph and not at slower speeds?
I changed the 1/2 shaft u-joints but never got around to do the drive shaft u-joints. I'll do that and check everything else, also.
Thanks. Might there be anything specific I should concentrate on considering this happens at 50 mph and not at slower speeds?
I changed the 1/2 shaft u-joints but never got around to do the drive shaft u-joints. I'll do that and check everything else, also.
Last edited by cor66vette; Sep 17, 2017 at 07:26 PM.
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From: Charlotte NC
I have no idea on anything specific to look at. I would climb under the car and have to inspect it all...like what I had mentioned.
I do not know hat the 'smoking gun' is. Thinking about load and stresses that cause this...I am trying to picture in my mind what it might be.
I do not know hat the 'smoking gun' is. Thinking about load and stresses that cause this...I am trying to picture in my mind what it might be.
Last edited by DUB; Sep 17, 2017 at 07:35 PM.
Thread Starter
Le Mans Master
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An easy fix, relatively speaking, to my rumble problem.
I've been planning to change out the drive shaft u-joints anyway, after I changed out the 1/2 shafts, so this gave me the motivation to get it done. I used the Spicer non-greaseable u-joints like I did on the 1/2 shafts. Forum member DUB had suggested them to me a while ago. Rumble gone - now it's smooth as.
Thanks for the comments and suggestions.
I've been planning to change out the drive shaft u-joints anyway, after I changed out the 1/2 shafts, so this gave me the motivation to get it done. I used the Spicer non-greaseable u-joints like I did on the 1/2 shafts. Forum member DUB had suggested them to me a while ago. Rumble gone - now it's smooth as.
Thanks for the comments and suggestions.
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Get the car up to 60-70 mph, then put trans in Neutral and let the car coast at that speed. Is the vibration/rumble still there? If not, it is unlikely to be associated with the engine or transmission.
Possible items in driveline to consider, include (in order of likelihood):
Wheel balance
Old tires (getting 'lumpy')
Driveshaft and/or half-shaft balance
Dry/binding U-joint (note: if joint have grease fittings, give them some grease and test again)
{ OOPS! Apparently posted this after you found the problem... }
Possible items in driveline to consider, include (in order of likelihood):
Wheel balance
Old tires (getting 'lumpy')
Driveshaft and/or half-shaft balance
Dry/binding U-joint (note: if joint have grease fittings, give them some grease and test again)
{ OOPS! Apparently posted this after you found the problem... }
Last edited by 7T1vette; Sep 24, 2017 at 07:33 PM.