Jona Gold

In my search to quiet down my transmission after installing a single mass flywheel setup I found lots of posts and other owners discussing ways to lessen the noise in their cab, so I thought perhaps one thread with as many as could be found would be helpful.

In my search the follow list was helpful

1. Overfill the transmission by 1 qt for 7 total quarts
a. Different fluids will lessen the harmonics- Mobile Trans SBC DC is the most recommended if you can get it or afford it- but there seem to be LOTS of viable options in this regard.

2. Add the 6.7L harmonic damper
a. I heard a very noticeable difference with this, plus it’s better for your driveline life.
b. To convert your 5.9L purchase the damper part # 68005166AA and the Fan Pulley 68002978AA. If you have a fan clutch removal tool- this takes about 90 minutes (maybe less), but costs (at this time) around $4-500 depending on where you order.

3. Still worried about driveline harmonics with your G56? Install the factory aluminum 1-piece rear drive-shaft, part number: 52123162AC. This is a simple install- drop your factory 2-piece, remove the carrier (center) bearing and then slide the driveshaft into the transfer case, bolting up the 4 bolts to the rear differential. Simple- done. Not a big difference in noise, but it smoothed out the shuddery start that developed after my single mass installation.

4. Add the shift tower boot included on some Ram’s, but not all (all rams will have the boot that goes up the shifter a bit- but this boot only goes over the tower on the transmission, as a second rubber layer between the transmission and the leather boot)- this was found on the Ram 4500 (this will only quiet the cab, it will not address the harmonics in the transmission).
a. Discussed nowhere, but recommended (and ordered for me) by a friend during my search, this little Gem is pretty cool. For less than $20 you can get 68069869AA and have it installed in less than 30 minutes. It’s cheap, it’s fast, and it makes a noticeable difference in transmission noise into the cab. See the pics- simply remove the two 13mm nuts to separate the gear shift lever from the shift tower, and then place the boot over the tower. Replace the lever and reassemble your console.





5. Of course- you could dyno mat your entire cab to block as much exterior noise as possible.

Any other suggestions? Anything else anybody has tried? This thread will hopefully help others, and as others find more ways, they will hopefully add to this thread.