Did you install any of the silicone sleeving?

 

yes, several times.

ie, installed it then removed it a couple times to make sure it was in the correct places.

 

2009 C2S 177K miles

Sounds like (pun) something is going wrong inside your transmission and these cables are merely transmitting the noise. Can you put the car in gear and running up on a lift with the wheels turning and put a scope on the transmission?

Peace
Bruce in Philly

 

Up until 2 weeks ago the car had the stock exhaust. The transmission has made no detectable noise since I purchased the car. The noise started when I added the cables, the noise goes away when I put the original cables back on, the noise goes away when the transmission is put into 1st and the numeric cables are fully disconnected. The noise is not present when the fore/aft cable is on and that cable is bolted to the same bracket as the side cable. I suppose its possible its in the transmission but that seems extraordinary unlikely.

 

I duuno.... the whole point of the Numeric cables is the elimination of the flexible plastic bits no? Those dampen noise transmission.

Peace
Bruce in Philly

 

sure, if it was the normal noise

 

** Final Update **

After a massive amount of trial and error, I finally figured out that the side shift cable bracket was very slightly bent. This seemed to have transmitted vibration on both the fore/aft and lateral axis. Bending it back reduced the 1st gear noise by ~50%. I then took the noise hose that came with the kit and closed all the gaps by spiral wrapping the cables with a heavy duty tape which cut out another ~20%. I finished things up with Dynamat on the interior cables where there was room and Dynamat and Dynaliner on key areas of the console which nocked out another ~10-15%.

So now I have the amazing shifting that comes with the cables and shifter and a very minimal amount of noise from the cables.

 

I just had the numeric cables installed in my 996. After the installation I had an unbearable amount of noise in the cabin. The cables transmit sound from the transmission into the cabin since the cables are so solid with no insulating plastics of any kind. I have had my car for 20 years and for the first time ever I considered selling it. Instead, I took out the center console and raised the parking brake mechanism to have full access to the cables inside the cabin. I wrapped each individual cable in Dynamat and then wrapped both cables together with Dynamat. I also completely covered the grommet at the firewall with Dynamat. Once I put the console back on the car I had zero sound from the cables and the car sounded exactly like it did with the stock cables. I should note that I first had the sound insulating tubes from Numeric installed and they did virtually nothing. I removed those tubes and used the Dynamat as described above. I'm loving the car again and the shifter with the cables really makes the car feel great. I wish Numeric provided Dynamat with the bundle (or at least recommended it in the instructions). It makes a major difference in a positive way.

 

Do you have a lightweight flywheel as well? I have the same issue (with a lightweight flywheel) and seems like the noise is amplified because of the FW. Anyone else have this issue with the lightweight flywheel and ways to resolve it? thanks in advance.

 

I have the exact same sound! Going to check out if the above solution helps. Thanks!

 

Installed numeric shifter, a few months later installed cables. There was a rattling noise every time I accelerated 1-6 gears. Went back to stock cables still shifts great and no noise. In my humble opinion, unless you are on track a lot and for extensive periods which puts a wear and tear on stock cables there is no significant decline in feel and performance in using stock cables. The Numeric shifter design, build and shift feel is a great improvement from the sloppy feel of the stock shifter. Event the stock short shifter does not give the Numeric shifter feel.

 

Amazing