[RicKaysen]

I'm only making this new post because I don't want to see it buried on the 20th page of a long ago forgotten thread. I brought my R/T back to the dealer for that humming sound that seemed to be getting louder. For some reason, it gets worse when the ambient temperature is warmer. Now that some days are approaching 60 degrees here in NJ, that noise is telling me there's definately something wrong. I had a tech take a ride with me to demonstrate the sound, but it wasn't as loud first thing in the morning when the temp was in the 30s. He noticed several other things that needed fixing that I didn't even notice, so that's one positive thing, but the sound remained a mystery. He rotated the tires just to see if they were the culprits and left a ticket open and told me to call back if the sound persisted. Well, it did and as usual, was louder when the day warmed up. They said, no problem, we'll order a new transfer case. I'll post again FYI if it cures the problem. The tech was great though...they don't often offer to fix a bunch of stuff the customer doesn't bring to their attention.

 

[razwierlink]

Yes My 2.8crd Is Now By The Dealer, Also Humming
Only Accelarate Form 100 To 130kmh Between 2500 Rpm And 2750rpm In 5
In 4 It Is The Same By Al Lower Speed (100kmh) But Same Rpm
Only By Accelaration Not By A Constant Speed, They Change Now The Torque Converter Rear Axle Diff. Is Already Changed. Hope It Will Help

 

[RicKaysen]

That sounds different than my problem. There is no humming sound during acceleration and up to 45mph or so. At a steady speed over that, the hum starts and is not affected by engine speed. It dissapears when the forward speed of the vehicle drops below 40.

 

[bobbypiano]

You should check the rear bearings first. I can't belive you would need a new transfer cas!!!Perhpas the gear oil is low.