I say do it before you get all the trash from band & clutches messing it all up. I baby my truck compared to most you guys & at 5,000 to 6,000 miles the stock stuff was not looking good. Pull your trans dip stick & rub your finger through the trans fluid. Then smell of it. If it has any burnt smell you probable have some burnt clutches & for sure a bad second gear band. Mine did and it was burnt. Glad Gregs guys tore it completely down & checked it out even though I was just there for billet servo's, stall & TransGo shift kit. Since it was all tore down he only charged me a $100.00 more to replace the 2nd gear band with a HD better one alos replaced all the disc with upgrades. I know Phoenix makes sure all is good before the install it back in the truck.