CAUSE OF 2000 RPM DRONE discvovered!

[betterthanstock]

CAUSE OF 2000 RPM DRONE discovered!

the cause of the drone is the front panel of the bed acts like a piano board amplifying and resonating badly. knock on your panel. It should make a dull thud, not a bell-like ring. I fixed mine by attaching 20 sheet metal screws to the plastic bedliner.

 

[Tim]

Wow!! You mean everyone was complaining all this time, and it's just the sheetmetal?

 

[MacHaggis]

I guess I have two thoughts. If the sheetmetal is amplifying the sound from a problem, it's doing you a favor providing an early warning.



If it's amplifying a normal sound to a level that it sounds like trouble, then you've solved a problem!



Hmmmm . . .

 

[betterthanstock]

I am not saying this is the cause of everyone's problem,



As far as what causes the bed to amplify the vibration, well, the frame could be unfortunately tuned (by accident of course) to resonate at 100 Hz (the cummins 2000rpm frequency, or one of its harmonics. Also every sheet metal panel has a specific resonant frequency. You want those to be outside of your normal operation frequency, or you will be unhappy.

 

[klenger]

Sure would have saved you a lot of trouble if you had tried that first. :-laf

 

[Dieselnerd]

I've noticed that on a very smooth road where there are no road noises to cover any other noise, I can hear a "hum" at 2000 rpm's but not at 1900 or 2100. It only happens with an empty bed so the sheet metal thing may be true. I wouldn't really call it a drone since it's not very loud and nothing vibrates. I have Line-X in the bed so that may be why it's not very noticeable except on a very smooth road. If we still had the old loud Cummins we would never notice these little sounds.

 

[rweis]

Huh?, can't hear you, the **** engine is too loud , but I love it Oo. and the soft whistle of the turbo as it cruises along, but then I liked the B-52 too. Use to call her the BUFF, BIG Ugly Fat "Fu. . er" er I mean "Fellow"



Bob Weis

 

[scootergmc]

Line-X solves the problem.

 

[WOT]

Anyone on here tried the kit mentioned?

 

[cwbyinjeep]

I just had my truck lineXed two days ago and the drone has significantly decrease. And of course LineX is very good at reducing resonance and road noise. So I think there is some truth to this. But I cringe at puting 20 sheet metal screw into my bed.

 

[EricBu12]

Do a Rubber undercoating that they sell in the auto parts store... . I did that the first day of my truck since it was so clean..... The cab of the truck has some but the bed has none... . So I did that amd my truck is very quiet...