"Purring" noise while coasting at medium speed. The noise is like a surging, muffled rattle. It sounds like a giant cat under my truck. The type of noise is similar to the harmonics of a bearing that is shot, running smooth for a second and then rattling for a second. The amplitude of the sound is such that it's difficult to hear if I have the radio on. But it's quite noticeable with the a/c and radio off, windows up.
I am the new owner of a 2016 Ram 2500, 4x4, 6.7L Cummins, 68RFE, with about 125k miles on it. I need to know if this sound is normal or if there's a problem with my transmission.
This sound occurs when I let all the way off the throttle at a speed range of about 45mph down to about 25mph. It may happen at higher speeds, too, but I just can't hear it. It will purr until the transmission releases (stops holding back the truck) at a speed of about 15-20mph.
If I shift into neutral, the sound goes away immediately, so it seems to be related to the transmission, not engine, drive shafts, diffs, wheels, etc. If I give it just the slightest amount of throttle, the sound goes away.
The exhaust brake is off. (The exhaust brake works fine.)
The sound is louder when the transmission is cold (not at full temp) and gets quieter at full temp (150F-160F).
I typically notice it while in trans gears 5 Lock and 4 Lock.
The sound seems to not be related to the engine at all.
It doesn't produce any vibration, as far as I can tell. It's just a noise.
Everything else works just fine.
I am the new owner of a 2016 Ram 2500, 4x4, 6.7L Cummins, 68RFE, with about 125k miles on it. I need to know if this sound is normal or if there's a problem with my transmission.
This sound occurs when I let all the way off the throttle at a speed range of about 45mph down to about 25mph. It may happen at higher speeds, too, but I just can't hear it. It will purr until the transmission releases (stops holding back the truck) at a speed of about 15-20mph.
If I shift into neutral, the sound goes away immediately, so it seems to be related to the transmission, not engine, drive shafts, diffs, wheels, etc. If I give it just the slightest amount of throttle, the sound goes away.
The exhaust brake is off. (The exhaust brake works fine.)
The sound is louder when the transmission is cold (not at full temp) and gets quieter at full temp (150F-160F).
I typically notice it while in trans gears 5 Lock and 4 Lock.
The sound seems to not be related to the engine at all.
It doesn't produce any vibration, as far as I can tell. It's just a noise.
Everything else works just fine.