I have a 2003 1500 Quad-Cab. It just turned 33,000 miles. Just last week, for the first time I noticed a humming or vibration when decelerating from about 60 mph down to about 40 mph. That's the only time it does it, just when coasting down a hill in that speed range. If I give it a little gas going down a hill, it stops. The first time it happened I thought I had a flat tire, that's how loud it was. I have discounted the engine, tranny and exhaust form being the problem because I threw into neutral when it was doing it on another occassion and the vibration was still there. I am thinking driveshaft, or rear axle or maybe a wheel bearing. It is very difficult to isolate where it is coming from. I only have 3000 more miles on the warranty so I will be getting it over to the dealer shortly. The truck has run trouble free till now, and this problem sure isn't normal. I will let you know how it turns out as soon as I bring ot to the dealer.
Anybody else having a simlar problem with their truck?
Chuck