I have a 1999 Jimmy 4x4w/80k miles and when at idle in Drive or in Park I hear a rattle coming from the trans area, sounds like a lose heat shield rattling.Also when pulling away from a stop sign under light load I feel a shudder. It feels like a truck with paddle tires moving slow.Yesterday while at the rifle range I talked to a guy whos Blazer makes the same noise and has the same shudder. What is it? I hope its not trans bands or front pump bcuz I just got the truck!

 

sounds like torque converter. low on fluid or going out. good luck

 

Did you ever find out what the rattle was? Mine is doing the same thing right now. I removed the flywheel cover and it sounds like it's coming from the torque converter.