There will be no problem with warranty, plow package or not, the plow package doesn’t add to anything beefier in the running gear, just a bigger alternator, and power Windows and rear sliding glass Which most trucks have. The running gear on the 1500 is pretty hardy I would be suprised it piled up, but with the additional weight on the front end you have mostly likely taken the transfer case out, plows add a lot of weight and gears mesh best in one direction, spinning the wheels in reverse or pulling in reverse is never a good idea. You may want to try putting the transfer case in neutral and reselecting high or low just to see if it is not completely locked in. The proper sequence is in the manual.