Hey guys, I drive an early '04 3500 with a turbo back 4" exhaust with a flow through muffler. Everything else is stock. Recently I have had a weird drone when I am accelerating that occurs in the range of 23-27 mph for a second or two and also when I am decelerating at or around the same speed range. The noise seems to be originating right over the center console area. I am currently on the road and plan on throwing it on the lift once I am back in the shop. Just wondering if anyone has experienced this or has an idea as to what could cause this....

-Cheers

 

It could be a loose exhaust part

 

The weird thing is that I only hear the drone at 23-27 mph and after inspecting it today I have eliminated all of the u-joints on the front and rear drive shafts. I am thinking it must be a bearing inside the transfercase or something slipping in the trans...

 

Carrier bearing in rear driveshaft? Could be transmitting the noise through the transmission.

 

Well I crawled under the truck and all of the u-joints on the driveshafts, both front and rear, are all tight. I'm thinking it has to be a bearing. Weird thing is though the past couple days it has warmed up and I cannot get the truck to make the noise now! Of course...