Toyota Repair: Vibration noise, vibration noise, sliping

Question
I am haveing a slight vibration noise when shifting from lst to 2nd but only occasionaly.  The service department thinks it may be a heat shield vibration.  I have a 2000 Sienna with 81,000 miles and always serviced by Toyota.  Do they nedd to loosen a heat shield when changing an oil filter?  The noise seemed to start after the last oil change.  Thanks

Answer
I thing there is a TSB on this, and if you had it looked at before 80k it's to r&r trany.  There was a lot of these sliping, vibrating and Toyota moved the warrty to 80k I think if not more.  I don't no how the dealership there is but the one I work at if you brought it in and it had 79,999, and you complaned about the trany, then it started getting worser at 81k , then it would still be coverd, please send me the vin and I will be more then happy to check on this for you.  It don't apply to all just some vins.