trans? noise

Prior to the expiration of my manufacturer warranty, I reported a problem to Rick Case Acura in Fort Lauderdale, FL. Upon acceleration, between 35 and 40 mph, there was a noticeable vibration or grinding noise that would occur for 5 to 10 seconds. The dealership said they could not reproduce the problem. The problem continued until I took the vehicle in for service in June 2010 and reported the same problem. This time I presented the dealership with over 100 reports of the same problem occurring in 2004, 2005, 2006 Acura MDS's and Honda Pilots (same transmission). In all cases, it was determined that the transmission torque converter needed to be replaced. Out of 29 complaints filed with the NHTSA for the 2005 Acura MDX, 14 complaints involved transmissions and 11 involved the 35 to 40 mph vibration/shudder problem resulting in torque converter replacement. Additionally, there was an NHTSA service bulletin #6003 issued in August 2007 (#10022468) stating "torque converter shudder or vibration between 35 - 40 mph" for the 2004 Acura MDX. It is apparent that this is a wide spread problem that crosses several years and both the Acura MDX and Honda Pilot. I do not understand why there has not been a recall or a class action suit to force a recall???

Its hard to guess at the source of a noise without being able to hear it first hand. Could it be an exhaust heat shield rattle. Frequently a heat shield on the exhaust will crack or a shield on the body will crack and only resonate at certain load or certain temperatures.

I have heard of the same issue in several forums. Same speed and symptoms. I have not yet found a fix for the problem. I have heard it described as the transmission "searching" for the gear. It seems as though the transmission should be downshifting, but it is not and the engine seems to bog out. I took mine to a dealer, and is often the case, the problem could not be duplicated. I will keep my eyes on the forums for an answer.