Attention: TDR Forum Junkies Dave Zuber
TDR MEMBER
I just got a 21, my fourth Cummins with a RAM attached to it. Big Horn, Crew, Shortbed, 4x4, at 1000 miles now.
It has a vibration that starts at 65 and goes to 72mph. Very noticeable right at 68mph and 1600 rpm. The engine does have a slight vibration at 1600 also, when under light load and the transmission is locked up, but that is barely noticeable in 5th or lower gears.
After doing an online search I found this from AAM, who makes our axle and I think the driveshaft:
https://www.demandaam.com/technical-support/aam-technical-tips/driveshaft-balancing
So, instead of turning my new truck over to a 'Flat Hatter' at the dealership, I tried balancing the driveshaft myself using that hose clamp technique. I bought a couple of 4 1/2" worm drive hose clamps, and on the first try I knew I was on the right path. One hose clamp made more vibration, but the frequency was exactly the same. On the ninth try (in 101 degree heat) I started to see some success. One hose clamp is too much weight, but two spread about 120 degrees was very close. I also placed them 1/2 way down the drive shaft. The sweet spot ended up centered at 90 degrees to the existing weight that was near the front of the shaft. Now the vibs in that 65-72mph area are greatly reduced. But, I may notice slightly more in the 50-60mph area. Still not sure about that.
Give it a try.
It has a vibration that starts at 65 and goes to 72mph. Very noticeable right at 68mph and 1600 rpm. The engine does have a slight vibration at 1600 also, when under light load and the transmission is locked up, but that is barely noticeable in 5th or lower gears.
After doing an online search I found this from AAM, who makes our axle and I think the driveshaft:
https://www.demandaam.com/technical-support/aam-technical-tips/driveshaft-balancing
So, instead of turning my new truck over to a 'Flat Hatter' at the dealership, I tried balancing the driveshaft myself using that hose clamp technique. I bought a couple of 4 1/2" worm drive hose clamps, and on the first try I knew I was on the right path. One hose clamp made more vibration, but the frequency was exactly the same. On the ninth try (in 101 degree heat) I started to see some success. One hose clamp is too much weight, but two spread about 120 degrees was very close. I also placed them 1/2 way down the drive shaft. The sweet spot ended up centered at 90 degrees to the existing weight that was near the front of the shaft. Now the vibs in that 65-72mph area are greatly reduced. But, I may notice slightly more in the 50-60mph area. Still not sure about that.
Give it a try.
