Quote Originally Posted by darknoodles View Post
[ not sure if this will help ] .. I should also add that, if i take my feet off the gas just before going into the next gear, the noise is more pronounced, i.e....

-> step on gas uniformly and reach say 3rd gear. While on 3rd gear, still apply gas as normal, but as it is about to shift to 4th gear, take feet off gas and just coast (no brakes)
-> drumming noise occurs like mentioned above. Done this way, the noise is sometimes louder, and overall the noise just appears more often. RPM is still around 1200-1300 when noise occurs.
That makes me wonder if it is a worn transmission issue or a worn engine mount. Have you been able to find out from the mechanic that did the auto transmission fluid change what fluid he used?