97 Silverado Rear End Rumble
 

sorry I posted this in new members. duh.
rear end rumble over 20 mph(at least that's when I hear it) kind of like a muffled locomotive. need a short list of what it could be's.
Note: Please understand, I'm a hair guy, not a machine guy, but I love my truck and when I have the right words from pros like you guys, I can usually hold my own at the mechanic.
Please advise.

When a rear end is going bad it will get louder the faster you go so it is possible you just don't hear it until 20 MPH or so. One tell tale sign of a bad rear end is the noise will change when you are accelerating vs. coasting (foot on the gas vs. not on the gas). A few other things to look for - bad universal joint, bad tire, or wheel bearings. Very hard to diagnose without actually hearing it and your idea of a muffled locomotive and mine might be different. You don't live near a train track do you? Just kidding - good luck!

Next step after rumble
 

I have a 99 2500 silverado that has gone past the rumble stage. (I must have missed it) It has gone directly to exploded. I was accelerating over some uneven road surface and I managed to throw the spider gear out of the open carrier and through the rear cover. Over the past couple of days I've been wrestling with the rebuild vs used issue and decided that rebuild was a better option. These rears are very expensive all seem to be located in MN? Sorry if this question is basic but I've been reading numerous blogs and forums about the rear and have seen a lot of conflicting info. Is this a 9.5 or 9.75 ring gear (GT4)? What is it called? A 10 bolt, GM 9.5, DANA something? Thanks.