You did what is called "Engine Braking" and it does sound very loud. Trucks do that all the time and it sounds like a plane taking off from the runway. Some towns ban engine braking by trucks due to the noise.
If it is working fine in D when you start out, then you should be fine. Do check the ATFluid level and condition (should be clear red/pink).
Last edited by Tony2005; 07/26/06 01:40 PM.