Hey everyone. I posted on Cumminsforum, but nobody like writing back. Hopefully, some more activity here.Anyway, my truck is making a new noise that is concerning me. As I'm driving, there is recently a lot of driveline whine which has gotten louder. Under power, it sounds like the rear. Just recently, there is a new addition to the party. When I let off the gas, and the engine is holding back from about 40-MPH to 10-MPH, there is a clicking noise that slows as the truck slows (remember, my transmission has a strong lockout). So, I thought U-joints, right? Well, I crawled under the truck and checked the front and rear u-joints and they seem fine. They are spicers after all. The front and rear fluid levels are good. So, I'm wondering the following.1. Would an auto transmission make a clicking noise when not under power (holding back), while operating fine otherwise?2. Would a transfer case just "go" and make a clicking noise? Perhaps the chain?3. Could it be something farther up the line? It seems to be centrally located to the chassis. 4. Would the center support bearing make this noise?Thanks in advance for the help. Of course, I'm getting ready for a big trip next week and would like to use my truck. Brian

Well as for noise and such if there is fluid in any of the cases check it closely for metalic debris (glitter). This will give the clue of what is going on. Debris or black graphite is a bad sign. :rolleyes:With all bearing it best to pull it out of place to check it. Like with U-joints pull the shaft out and move it in all direction feeling for binding or gritty feeling. Same with the center support bearing twist feel for loosen and binding.If the trans in neutral coasting does it continue or change?How about if you get it in to neutral of the transfer case?

Bmac,Have someone drive it for you, and hop in the bed. (or you drive with a buddy listening) I see your camper shell, so that may help or hurt. My brother and I have had really good success with this procedure to narrow down noises. We just find an empty parking lot and speed up, slow down, turn, brake, etc. We can usually get so much closer to the real location of the noise.Definitely try different transfer case positions. You use whine and clicking as descriptors. Do you have both? Clicking to me is usually a once per revolution or multiple there of. Bearing balls passing a bad spot in a race, tight spots in a spicer joint, limited slip grabbing. A whine to me is more constant, no definite on off (could still be a pulse, but at a frequency I can't distinguish.) Depending on which pinion bearing is failing, the whine could be during power application, or coast.HTH HagGL HTHHag

Good info so far. I see you have a long bed too so I'm guessing you thoroughly inspected the carrier bearing as well. Also, just because a u-joint isn't obviously flopping around doesn't mean there isnt a dry or rusted cap making noise. Exploring all variables is sometimes the only way to track such issues. Like decelerating in all gears, in and out of 4wd, turning, forward/backwards, etc. Having someone listen with you helps.

Yeah also grab the pinion and see if its loose?