Excellent! Another saved 4T65E tranny!
Another tip is to change the fluid and filter often, much more often than GM recommends or others for that matter. My 2001 GP is driven about 25,000 miles per year and I have been changing the trans and filter every year now for the last 5 years, especially since the mileage is getting high now. I drive mostly highway, high speed-aveage is about 80 MPH, but do not beat on the tranny at all. If you do mostly highway and are nice to the tranny, I would think you could go longer between trans fluid/filter changes but I would not go more than 35,000 miles-just me-doing this a long time. If you do mostly stop and go driving, I would change the fluid/filter, once a year, regardless of mileage. I use Walmart Supertec Dexron VI-$4/QT, NOT Dexron III-OEM Fluid Specified by GM before Dexron VI was available. Dexron VI is a MUCH better trans fluid-use it and it is backward compatible to Dexron III. Do not listen to the forum "experts" who are not! Trans fluid change will cost 8.5 QTs x $4/Qt=$34 +20 for the filter=$54. It's the best $50 you can spend on your GP and MUCH cheaper than $2-3K for a rebuilt junk tranny, unless you get a specialized 4T65E beefed up from a vendor like Triple Edge Performance-not to mention the time and effort to make the switch.
Hope that helps!