Been noticing and hearing a whinning coming from my transmission. When I proceed from a dead stop, it starts as a low whine and gets louder as it shifts to the next gear. Then low again to higher as it enters the next gear. Shifts of gears are normal and smooth, no knocking sounds or hard shifts. My 00Regal LS has 110k mi. Any ideas of what may be causing this noise. Would like to hear a pre- prognosis before I take it to a facility. Just to mention I change the AT filter and fluid religiously every year. It was last changed this past Feb/07. Thanks.

It could be mechanical internal to the tranny or possibly high line pressure. Our 4T65E autotransaxles have known problems with the PCS solenoid. It can cause the whining sound. Have it scanned with a trans capable scanner and see if a DTC of P1811 is stored. This DTC does not trigger the SES/CEL light. When it sets it commands max line pressure. Normally you get harsh shifting but not always the case.