Ever since I bought the truck, it made a whining noise. Originally I though it was something under the dash as it sounded electrical/mechanical, and not necessarily a high pitched whine. Today I took it to one of my local mechanics and he took it for a test drive. Now, the noise is a whining noise that starts when the truck starts moving. It winds up with speed. The mechanic said it wasn't coming from the dash, but the drive-train, possibly the transmission. He thought that maybe the tail bearing might be going out, or possibly the carrier bearing for the split drive-shaft. Next week I might take it back in and have him run a microphone test on the drive components so he can isolate where the noise is coming from. Ultimately my question is has anybody run into this type of problems before with this trans? Another thing I want to add to is that the trans was replaced by the previous owner about 3 months ago, and I don't know if it was a re-build or re-man.