n5oxp

My 3500 4x4 six-speed has been at the dealer for the last week. A noise recently developed when I would shift out of 3rd, 4th, and 5th. It occurs as I begin to accelerate and goes away after a certain rpm is reached. It is not really a grind or a whistle, but more like wind noise ( I'm not saying it is wind noise, just the closest comparison to describe the sound). Additionally, when I let the truck pull itself at idle in first gear with the window down, I can hear a slight chirping/clicking noise from under the truck which directly increases in frequency with acceleration. Dealer was finally able to hear the noise but says this is normal with age (55K miles). I'm not convinced. Any thoughts?

Mathew

You almost certainly have a driveshaft u-joint failing. I imagine it is louder with more load at slow speeds?

Take it for a highway speed drive, then get under there and feel each yoke ear. One will likely be very warm .....

I had the same symptoms on mine at 20,000 miles.

Mathew

n5oxp

I just checked the u-joints on the driveshaft for myself and it is obvious that the needles have fallen out of the one at the rear diff. I had this one replaced at 35k so I really didn't want to think it was bad again this quick. I think someone on here mentioned going to a greasable u-joint so I probably will check into that. I guess the u-joint didn't throw a code since the dealer was unable to locate and fix the problem.