This may have been posted before but some may have missed it. The magnet posts over in oil filters reminded me of a problem with the GM 4T40,45,65e and the 4L60 transmissions. There is TSB out on the magnets and this should be done. GM put a refrigerator type magnet in many of these and they should be replaced with 2 round ones. The small flat magnet that came with the trans can get saturated and cause the solenoids to pick up what the pan magnet should have got and cause an expensive repair. You can get them for $1.49 a pair at Home Depot. If you haven't already done this do it at the next filter and fluid change. It may save you from a transmission problem in the future. TSBpdf download, change the file extension to .pdf if not done automatically) http://www.revbase.com/BBBMotor/TSb/DownloadPdf?id=175688