Topic: Rear Noise
in Forum: C4 Driveline Components
Got a harmonic type noise at high speeds but not 65 - 70. Opinion on whether I should tear into replacing u-joints and do wheel bearing while I'm at it.
I'm new at this so be kind!!!
|UPDATED|10/3/2011 5:02:25 PM (AZT)|/UPDATED|
Love my C4!
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the dynamic duo

c3vr life member #97
Moderator

So...is this an actual noise you hear, or a vibration you feel? If it is a fine vibration that sorta comes/goes at speed, that points to a balance issue, prolly the driveshaft itself...may need u-joints. The halfshaft u-joints could also cause this to a lesser degree. Of course, a tire/wheel imbalance can do it, too, but that is usually a heavier feeling vibration.
Joel Adams
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Thanks for pointing this out; getting my tires checked this afternoon.
Love my C4!

So...is this an actual noise you hear, or a vibration you feel? If it is a fine vibration that sorta comes/goes at speed, that points to a balance issue, prolly the driveshaft itself...may need u-joints. The halfshaft u-joints could also cause this to a lesser degree. Of course, a tire/wheel imbalance can do it, too, but that is usually a heavier feeling vibration.
Not feeling a vibration. Once I hit 75 or faster there is a "hum" (not high pitch, kinda baritone) that get louder the faster I go and softer to gone as I slow down.
I've not noticed any unusual wear on my tires, but will be getting those checked out. Wonder if I should do an alignment?
Love my C4!
Moderator
While driving at the speed that you hear this hum, turn the steering wheel just a little to one side(left or right), and see if the noise changes at all. Do this to the left and right. It's best to do this one a road with little traffic.

IF you hear a pronounced difference in the noise, then yer looking at a wheel bearing issue. If you hear no difference at all, then I would think you have a tire noise...
Joel Adams
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Okay, Vette guys, here's an update:
Had my tires checked, rotated/balanced. Couldn't hear the noise coming home but I'm going to take my Corvette out to the same road where I would hear the noise and run it up to the speed where I first noticed the noise. Will let you know what I find.
Appreciate you all so much!!!
Love my C4!
Moderator
Hmmmm....reckon the noise could simply be road surface related?
Joel Adams
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Moderator
Okay, Vette guys, here's an update:
Had my tires checked, rotated/balanced. Couldn't hear the noise coming home but I'm going to take my Corvette out to the same road where I would hear the noise and run it up to the speed where I first noticed the noise. Will let you know what I find.
Appreciate you all so much!!!

it's a good idea to have the tires rotated/balanced periodically. when i bought my new tires got the lifetime rotation and balancing on them. every 5000 mi, both get done. i believe it ran me about 80 bucks for the policy. both get done each time.
as joel pointed out it also could be just road noise. try it on the road you were on and then on a road that you can do the same speed (safely) and check if there is any difference.
the dynamic duo

c3vr life member #97