A4 transmission "clunk"
Thread Starter
Racer
Joined: Dec 2022
Posts: 273
Likes: 142
From: North Central Ohio
A4 transmission "clunk"
Have a fairly recent condition with my transmission linkage. After initial startup and I put it into reverse, the linkage is quiet, but after I drive it and put it into reverse to back into a parking spot II hear a single "clunk" sound. It shifts fine and readily goes into gear. The cable itself is a brand new GM piece and is only a couple of months old. I just did a readjustment on the cable, and the linkage itself feels tight, shifts easily and don't feel any binding. Any ideas out there, or is this a normal sound?
Thread Starter
Racer
Joined: Dec 2022
Posts: 273
Likes: 142
From: North Central Ohio
The half shafts were replaced this past winter, although they weren’t GM units. I guess I will put it back up and give them a look. I still have the originals which I planned to have rebuilt this winter, may have to accelerate that plan.
Thread Starter
Racer
Joined: Dec 2022
Posts: 273
Likes: 142
From: North Central Ohio
Think I found the source of my clunk. Half shafts feel solid, but when I rotate the wheel hub I get this: the hub is moving inside the rotor. It is the same on both sides. Is this normal driveline slop or something wearing out in the diff?
Last edited by MSOH; Nov 24, 2023 at 12:16 AM.
Thread Starter
Racer
Joined: Dec 2022
Posts: 273
Likes: 142
From: North Central Ohio
I guess my video didn’t load correctly. The hub and studs are moving within the rotor stud holes approximately 1/16 inch, it looks like the stud holes have been enlarged. It is the most movement I have ever seen. I will try to load the video again.
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
Oops I managed to load the video. I would not expect any relative movement with the lug nuts at 100 foot pounds. The rotor stud holes look OK to me. The rotor is centered by the machined rotor center and hub machined center.
Thread Starter
Racer
Joined: Dec 2022
Posts: 273
Likes: 142
From: North Central Ohio
Yeah, I wouldn’t expect any movement either with the lug nuts torqued to 100ft/lbs. There does seem to be more slop around the stud holes than I’ve seen in other rotors I’ve installed over the years. The strange thing is, I only get the noise when I put it into reverse after a drive. I’ve rechecked the spindle nuts and they are tight and the diff mount still appears to be sound. I may just try new rotors and see if I still get the noise.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Safety Car
Joined: Aug 2011
Posts: 4,449
Likes: 409
From: Portland OR
I think if you pull the axle out of the hub and use some heavy grease on the splines, the clunk will go away.
There is a little slop there, and possibly more with non stock axles. The grease cushions the clunk.
There is a little slop there, and possibly more with non stock axles. The grease cushions the clunk.
Thread Starter
Racer
Joined: Dec 2022
Posts: 273
Likes: 142
From: North Central Ohio
Hey RonSS,
Finally got to trying your suggestion over the weekend and drove the car today, the clunk is virtually gone! Great advice! Will now get my factory shafts in for rebuild and get them installed over the winter. Thanks again!
Finally got to trying your suggestion over the weekend and drove the car today, the clunk is virtually gone! Great advice! Will now get my factory shafts in for rebuild and get them installed over the winter. Thanks again!