Pulsing drone noise

[RGower]

I am getting a pulsing drone sound from the drivetrain area while cruising at 54-56 mph and 64-66 mph. It is more noticable while under load, going up hill or with a load on the truck. No change in rpm or engine performance. It is not present at other speeds or when I take my foot off the accelerator. I have ruled out tires. I do not get any noticable vibration. Any thoughts would be appreciated.



03 3500 SRW, 250 hp, auto trans 48r, 75000 miles

 

[AMassaro]

Many have had similar situations. Sometimes it's the exhaust, sometimes it's the driveline. I had it. It was between 60-65mph, pulsing drone noise as stated. It went away after I had my trans built including new converter and billet flexplate. I don't know if that was my particular fix, but it's gone now and I'm glad. Do a search hear on "vibration" or "drone" and you should find alot of threads.

Good luck

 

[RGower]

AMassaro, thanks for the helpful information. I now have my suspicion it is the torque converter. Although not good news at least I have somewhere to start when I see the service technician.

 

[pipeguy]

Have you checked the U-joints?

 

[RGower]

I had the front axle U joints replaced last year and the drive shaft U joints replaced in January. I will have them check the front drive U joints (trans case to front diff. ). The transmission functions like new - no shift problems at all. It is a bit of a mystery, since the noise is so speed specific.

 

[Dieselnerd]

This was discussed quite a bit last year. Some have reported that it's the bed sheetmetal vibrating at those speeds, especially around 65 mph. Some claimed to reduce or eliminate the noise with a spray in bedliner. I had a similar noise around 65 that went away after I had a spray in bedliner installed.



Lot of things vibrate on these trucks at certain speeds. Look at the weight they added to the power steering hose to eliminate a noise. Who would have thought of that?

 

[Aliff]

my 99 4x4 5 speed did the same thing.

my 04 4x4 auto does this also but not quite so bad.

im not shure but i dont believe its an issue.





good luck!

 

[RGower]

I took my truck into the Dodge dealer and told the diesel tech about the pulsing drone noise and the suggestions I had received from the TDR members. He took the truck for a highway speed test drive to determine the cause and ruled out the transmission and differentials. At first he thought it was my front axle u joints as they were shot again (this will be the second replacement with 78000 miles on the truck). He replaced them with greasable after market u joints this time. The pulsing drone was still present so he checked the main drive shaft. It was also shot and was replaced. Apparently the shaft has internal guts and they had come loose. Enough out of balance to create the speed specific drone but not enough to cause a vibration. So far the noise has not returned , it looks like he solved the problem. I will give it a good test next month when I load the camper and kayak trailer and head off to Lake Superior.

 

[1965LONEWOLF]

I am getting a pulsing drone sound from the drivetrain area while cruising at 54-56 mph and 64-66 mph. It is more noticable while under load, going up hill or with a load on the truck. No change in rpm or engine performance. It is not present at other speeds or when I take my foot off the accelerator. I have ruled out tires. I do not get any noticable vibration. Any thoughts would be appreciated.



03 3500 SRW, 250 hp, auto trans 48r, 75000 miles

I HAVE THE SAME PROBLEM , DID ALL MY OWN TESTING , ALL NEW U-JOINTS , CHECK THE TIRES , USED DIFFERENT TIRES , EVERYTHING , DEALER WANTS TO KEEP THE TRUCK FOR A WEEK TO DETERMINE WHAT THE PROBLEM IS ? MY PROBLEM IS I DON'T HAVE A WEEK TO GIVE UP JUST TO FIND THE PROBLEM & THEN ANOTHER WEEK TO FIX IT - REALLY THE ONLY THING TO ***** ABOUT BUT ITS DRIVING ME CRAZY -

 

[RGower]

The noise is gone. Just returned from a trip with 20 hours of highway driving. The truck was fully loaded with Bigfoot camper and kayak trailer and no drone. The main drive shaft was the culprit, with the internal guts having come loose it was enough to create the noise but no vibration. Many thanks to the Chrysler diesel tech for his quick diagnosis of the problem. It really did sound like a transmission problem. If you experience this problem have them check the drive shaft first. It was definitely my last suspicion. See my first entry on this thread for more details on the noise. Hope this is of help.



2003, 4X4 3500 SRW, 250 hp, 48re auto trans. Timbren rear suspension supports. Bigfoot 8. 2 camper, kayak and mtn bike trailer.