grinding noise assistance
Thread Starter
8th Gear
Joined: Feb 2022
Posts: 8
Likes: 1
grinding noise assistance
Looking for some assistance and/or opinion on a consistent grinding noise coming from the rear of my ‘78 Silver Anniversary. It doesn’t happen from a cold start, it happens after I’ve been driving the car for a little while. It happens in fwd/rev and braking/not braking. I had the brakes replaced last year, and the leaf spring replaced. Thank you for any advice that anyone might be able to provide, or even any guess. I’ve had other non Corvette owners tell me that everything from that it could be the emergency brake rubbing something with the gear box, position differential. Quick Video attached (volume up).
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,205
Likes: 4,295
From: US-PNW
That's a tough video to separate the background sounds and it's very short. Is the noise you're talking about the rhythmic ratcheting sound in the first few seconds? Maybe better would be to drive the car and record the noise from the interior (windows up, radio off, smooth & consistent speed, at least 10 seconds long).
If you do hard turns to the left and right in an open parking lot, is the noise different in any way?
Do you feel it as a shudder or vibration when driving?
Does it sound as though it's coming from a specific side or just somewhere in the rear?
The emergency brake hardware isn't close enough to a gear box to have any effect. A binding emergency or disc brake will cause crazy-high heat on the bound side and easily felt with a touch of the hand on the wheel's hub.
One more question: was the change of brakes and spring an attempt to address this or did the noise appear after the work was done?
If you do hard turns to the left and right in an open parking lot, is the noise different in any way?
Do you feel it as a shudder or vibration when driving?
Does it sound as though it's coming from a specific side or just somewhere in the rear?
The emergency brake hardware isn't close enough to a gear box to have any effect. A binding emergency or disc brake will cause crazy-high heat on the bound side and easily felt with a touch of the hand on the wheel's hub.
One more question: was the change of brakes and spring an attempt to address this or did the noise appear after the work was done?
Last edited by barkingrats; Jun 14, 2026 at 09:50 AM.
Melting Slicks
Joined: Nov 2006
Posts: 3,423
Likes: 1,828
From: Apple Valley, MN
Check the end play of the differential stub axles. In severe cases, you can see damage to the differential housing as the U-bolts start fly cutting the housing.
If no damage, add a couple bottles of Delco 10-4003 to the differential and do some slow figure 8s to get the additive into the posi clutch plates.
If no damage, add a couple bottles of Delco 10-4003 to the differential and do some slow figure 8s to get the additive into the posi clutch plates.
Thread Starter
8th Gear
Joined: Feb 2022
Posts: 8
Likes: 1
That's a tough video to separate the background sounds and it's very short. Is the noise you're talking about the rhythmic ratcheting sound in the first few seconds? Maybe better would be to drive the car and record the noise from the interior (windows up, radio off, smooth & consistent speed, at least 10 seconds long).
If you do hard turns to the left and right in an open parking lot, is the noise different in any way?
Do you feel it as a shudder or vibration when driving?
Does it sound as though it's coming from a specific side or just somewhere in the rear?
The emergency brake hardware isn't close enough to a gear box to have any effect. A binding emergency or disc brake will cause crazy-high heat on the bound side and easily felt with a touch of the hand on the wheel's hub.
One more question: was the change of brakes and spring an attempt to address this or did the noise appear after the work was done?
If you do hard turns to the left and right in an open parking lot, is the noise different in any way?
Do you feel it as a shudder or vibration when driving?
Does it sound as though it's coming from a specific side or just somewhere in the rear?
The emergency brake hardware isn't close enough to a gear box to have any effect. A binding emergency or disc brake will cause crazy-high heat on the bound side and easily felt with a touch of the hand on the wheel's hub.
One more question: was the change of brakes and spring an attempt to address this or did the noise appear after the work was done?
Thanks for the reply Unfortunately the site will only me to upload a video no more than 4-5 seconds
To answer your questions:
- the noise is towards the end of the video. It sounds like someone walking on creaking hardwood floors
- the noise doesn’t seem to happen when driving straight—only very low speeds, forward and reverse, and when the wheel is turned (even slightly)
- it’s definitely coming from the rear. Maybe more the passenger side.
- I don’t feel a shaking, vibration(s), of the car
- the brakes were not replaced due to this and leaf spring was optional (lighter one)
Melting Slicks
Joined: Jul 2005
Posts: 2,651
Likes: 864
You might want to get an inexpensive IR temp "gun" that lets you read component temps. Go for a few mile ride, and check the brake rotor temps (you should be able to do it "through the wheels" - or from the inside). Both rear wheels should be roughly the same - if one is significantly higher - that indicates a brake is dragging.
But if it happens ONLY when the car is turning - I would tend to suspect something diff related. I'd probably drain the diff fluid, and put in new fluid with some of the Delco Limited Slip additive that 69L88 mentioned above.
But if it happens ONLY when the car is turning - I would tend to suspect something diff related. I'd probably drain the diff fluid, and put in new fluid with some of the Delco Limited Slip additive that 69L88 mentioned above.
Instructor
Joined: Nov 2020
Posts: 147
Likes: 28
From: Colorado Springs
My 78 had similar issue after a brake job. The pin that keeps the pads in place lost its cotter pin and the pin would randomly back out and crash into the wheel rim. Made s horrible grind. Sounded like it was from the differential but actually was the right front brake. Easy check-easy fix.
Tech Contributor
Joined: Aug 1999
Posts: 15,193
Likes: 4,018
From: Connecticut, USA
Typical noises
- Posi clutches- usually shows up after driving, coming to a stop, turning left or right, chattering from the diff.
- Parking brake hardware, springs break, shoes drag, creates a lot of heat and noise. If the rotors are still riveted on that is a clue.
- U-joint bind from worm, rusty joints
- Bad rear outer bearings
- Differential axles hitting the housing, metal scrapping sound. 78 differentials had issues.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
5 Best & 5 Worst Corvette Daily Drivers
Joe Kucinski
The Headlights of Every Corvette Generation Explained
Joe Kucinski
5 Best & 5 Most Overrated Corvette Track Packages of All Time!
Joe Kucinski
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
Drifting
Joined: Feb 2001
Posts: 1,540
Likes: 63
From: new ulm mn
I've got the exact same thing going on with my '76. Changed out the differential fluid with 2 bottles of additive. Did not change anything. BTW, the differential was extremely low when I drained it. (sucked it out). The differential has 115k miles on it and has never been overhauled. Been meaning to check the u joints and brakes. The bearings are good. Too busy to check right now. I can not tell what noise you are talking about in the video, but your description is mine exactly. I will post my findings if I figure something out. Please post if you figure your noise out.