Help! Clicking noise

[guido53]

dear Vette friends
I live in Italy, I have a 1975 Vette imported directly from Texas 7years ago.
The car runs fine but it always had a small annoying clicking noise .
- This "click" noise is not strong, it is easy to hear it when running with open window, but not with closed window; it seems to be coming from under body, but it is not easy to be sure of that.
- This "click" noise is peroodical and follows car speed - i.e, at 20mph speeds it is almost 2 click per second, and increasing speed the click frequency increases proportionally-
- The "click" sound doesn't follow engine rev number; with car steady in idle whatever the engine rev number there is no "click" sound at all
- The "click" sound doesn't change with different gear position, infact changing gear at same running speed the click frequency doesn't change, and also putting gear in idle it doesn't change -i.e if I put gear in Idle and let the car run freely the click frequency doesn't change- The transmission is the stock automatic original one and works properly.
- The "click" sound doesn't change nor with cold or hot engine staus neither with weather condition
- The "click" has no relationship with breaking or accelarating status
- Only after a long drive -at least 40miles- the click sound decreases and fades out, but the day after it is present again

Here in Italy there are no workshops with real good know-how on these USA cars; I tryed several "italian experts", I got different ipothesys and suggestions but no one could tell me he surely knew what's the cause and how to eliminate this noise;
So if anyone on the other side of the Atlantic ocean can help me with similar experience and its results I really would appreciate it and I'd thank him

Guido

 

[Huskerman]

Welcome to the CAC Guido, when you get a chance post some pictures of your car. Hang on and some C3 guys should be able to point you in the right direction concerning your ticking noise. Have you checked out the brakes and brake pads? That's just my first thought .........

 

[bill81vette]

Welcome to CAC!!!

 

[BigJimZ16]

Welcome to the CAC Guido, when you get a chance post some pictures of your car. Hang on and some C3 guys should be able to point you in the right direction concerning your ticking noise. Have you checked out the brakes and brake pads? That's just my first thought .........

Disc brake pads were my first thought as well, cheap and easy to change...

 

[timvette]

aside from wheel bearings, u joints, have speedo cable checked, if speedometer needle isnt steady, thats a good indication

 

[guido53]

Hello

At first, thanks to everybody for the answers:
during Xmax holidays I got brakes checked, I saw in right front brake a little leak, so I took off and revised all four brake calipers, I changed the caliper O-rings, didnt change the brake pads because about 70%, I also changed the two rear brake final pipe because they looked old and worn -th front ones have been changed two years ago-; then filled-up with new DOT4 liquid.
Result: breaking is improved, I eliminated the previous light tendency to go right during hard breaking ......but the clicking noise is absoulutely unchanged; no more no less than before. At least breaking preformance is improved.

I tryed to understand where the "click" sound comes from; I am not sure but as said by Timvette I suspect the speed cable: its proportianal to speed only, and it looks to come from somwhere under the.
I could try to disconnect the speedo cable, drive around and check is click disappears; I'll let you know
Thnak again And excuse me for my poor english


I uplode a picture of my Vette but it displays very small!

Guido

 

[guido53]

Sorry

Sorry
I realized now that it looks small but pointing on it it displays large enough
Guido

 

[Huskerman]

Nice C3 Quido.....glad the brakes work better anyway.....

 

[Copdogcorvettes]

Check the chrome rings on the wheels if you have them. That is a long time problem with the stock rings. One clip will break and they click against the rims when going down the road. I learned the hard way after replacing the rear wheel bearings on one side and still had the noise. ad Replaced the beauty rings and no more click sound. To check this just remove the rings and take it for a drive. Noise gone you know the problem. Good Luck and Welcome to CAC

Gary

 

[guido53]

Interesting suggestion

Hi Gary
I want to be sure about my understanding::eyerole
With "Crome rings" do you mean the stock external wheel covers, originally named by GM "Rally weels"?
If my understanding is correct you mean that the "click" sound would be produced between one of these wheel covers and the rim of the wheel. It would be amazing!
If I misunderstood please could you describe your suggestion in other words?
Thank you for you help

Guido

 

[Copdogcorvettes]

Hi Gary
I want to be sure about my understanding::eyerole
With "Crome rings" do you mean the stock external wheel covers, originally named by GM "Rally weels"?
If my understanding is correct you mean that the "click" sound would be produced between one of these wheel covers and the rim of the wheel. It would be amazing!
If I misunderstood please could you describe your suggestion in other words?
Thank you for you help

Guido

Yes that's what I was talking about the Chrome beauty rings that are on the Rally Wheels. If you have the factory Alloy wheels then you don't have them.
Gary

 

[guido53]

I will check them

Hi Gary
Thank you for the answer; in fact I have the stock Rally wheels with original chrome covers.
I also remind that soem years ago due to an hole in the road I lost one of those chrome covers, furtunately I was driving slowly in a town street, I heard it, I stopped and picked-up my lost cover. I realized that one clip was broken and another one was missing, so two clips only didn't keep the cover in place.

Now here we are looking at the falling snow, so I thing that next weekend will not be the best one for driving around with a '75 rear driving Vette; it could be funny but also very risky for car body health
During first good weathere weekend I'll check if driving without covers will make the click disappear. It would be amazing
I'll let you know
Thank again
Guido

 

[Copdogcorvettes]

It is worth the time, hope that is all it is. I wish I had try that could have save me several hundred dollars. I'll wait to hear from you.

Gary

 

[VetteV8]

Now here we are looking at the falling snow, so I thing that next weekend will not be the best one for driving around with a '75 rear driving Vette; it could be funny but also very risky for car body health

Guido

Snow, even in Ferara?
I thought it was getting cold here [-8C, -12 with chillfactor]
Anyhow, keep it out of the salty roads...

Cor

 

[guido53]

Hi Gary
Sorry, I forgot to answer before.
At the end of March, when snow, ice and worst weather were gone I did the test; I checked one by one the external chrome rings of the "Rally wheels",
I put small rubber shims between the chrome ring and the wheel rim as to fill any small seams, then I checked with a short drive around if the clicking noise was still there or not.
First test on the rear right....no change
Second test: one the rear left ...MIRACLE!!!
the noise was completely disappeared !
I removed the chrome ring and reinstalled it firmly without rubber shims, the noise was there again:
so I removed it again and put some pieces of sticky neoprene rubber under it and installed it again.. no noise at all!

It is really incredible; I had to stand that tiresome noise for years,madad while it was so easy!
Fortunately I didn't listen the two "great experts" I asked an opinion; the first one suggested to open the differential gear and the second one to dismount and rebuild rear brakes:ugh:ugh:ugh
So I could enjoy even more my Vette

Unfortunately last Saturday whil coming home from an american car meeting, while I was on the highway, I started to feel a small vibration from the rear; at first I thought about having lost a wheel balancing lead; then the vibration incresed, so I slowed down, and after few km the rear left tire tread broke away.
Fortunately the jack was OK the spare tire - I suppose a 37 years old GR70 "International tires"- was still good and after one hour of work and a stop to next gas station for pressure check drive slowly bute i got at home

So the Vette now is waiting for four new Cooper Cobra from the USA; I will take the occasion for cleaning and repainting the wheel rims and checking with attention all the Chorome ring clips

Thank you again for your very very very usefull suggestion
Guido

 

[Dad]

You need to pay attention to that left rear ring and make sure it is not rotating while you are driving, cutting off the valve stem. There may be insufficient holding power with the few clips left and those are worn.

Good luck

 

[Hib Halverson]

Guido-

The community of Corvette owners in Italy is small so I figure many of you know each other.

Have you ever met my friend, Alberto Raggi of Arluno, near Milan?

He owns several Corvettes and does a lot of work on them.

 

[Copdogcorvettes]

Guido, I'm glad that's was all that was wrong. Sometimes it is the little thing that make the difference. Good luck on the new tires. Agian glad I could help in some way. Gary

Hi Gary

Sorry, I forgot to answer before.
At the end of March, when snow, ice and worst weather were gone I did the test; I checked one by one the external chrome rings of the "Rally wheels",
I put small rubber shims between the chrome ring and the wheel rim as to fill any small seams, then I checked with a short drive around if the clicking noise was still there or not.
First test on the rear right....no change
Second test: one the rear left ...MIRACLE!!!
the noise was completely disappeared !
I removed the chrome ring and reinstalled it firmly without rubber shims, the noise was there again:
so I removed it again and put some pieces of sticky neoprene rubber under it and installed it again.. no noise at all!

It is really incredible; I had to stand that tiresome noise for years,madad while it was so easy!
Fortunately I didn't listen the two "great experts" I asked an opinion; the first one suggested to open the differential gear and the second one to dismount and rebuild rear brakes:ugh:ugh:ugh
So I could enjoy even more my Vette

Unfortunately last Saturday whil coming home from an american car meeting, while I was on the highway, I started to feel a small vibration from the rear; at first I thought about having lost a wheel balancing lead; then the vibration incresed, so I slowed down, and after few km the rear left tire tread broke away.
Fortunately the jack was OK the spare tire - I suppose a 37 years old GR70 "International tires"- was still good and after one hour of work and a stop to next gas station for pressure check drive slowly bute i got at homeView attachment 14319

So the Vette now is waiting for four new Cooper Cobra from the USA; I will take the occasion for cleaning and repainting the wheel rims and checking with attention all the Chorome ring clips

Thank you again for your very very very usefull suggestion
Guido