I have a 2005 silverado 1500. Just had my transmission rebuilt a few weeks ago. I'm having some problems now though. When I start my truck in the morning and I shift into reverse and slowly back down my driveway the truck shakes, but when I'm back into drive it seems fine. Any idea on what this could be? Transfer case maybe? I have no idea but I'm really sick of dumping money into the truck. Also is there a possibility that my cats could also be bad, when I drive it sounds like little stones being tossed around in a tin can. Any info would be very helpful. Thanks

 

Check for a broken or loose motor or transmission mount.

 

I can't say what the shaking in reverse is. I'm having the same problem in my 2006 Silverado 1500. But that rattling in your cats that sounds like stones is most likely the honey comb has broken apart. Mine did the same thing, then it stopped and I didn't give it much more thought until I started trying to figure out why my check engine light was on. The obd II told me I was having an issue in bank one, which is the driver's side cat. So I decided to cut it out and have a look. What I found was that there was nothing in there. The comb had broken up and is probably in my exhaust.