Dealer always tries to say any alterations to the vehicle will void the warranty. Their suits that always try to protect their bottom line. First they have to prove whatever aftermarket add-ons caused the issue. I have been modifying trucks since I started driving, I can't keep anything stock. Never had a problem having warranty work done. The guys on the floor are usually also gear heads out of work and will take care of you to get it taken care of under warranty. I have a 2005 1500 with 6" lift and 35's. Had a real bad vibration in the rear and knew I was going to need a one. Service manager was giving me a hard time at 1st after seeing a lifted truck, I said you didn't even look at it yet so you can't tell me what's wrong and if it will be covered under warranty. After I dropped it off, got a call 2 hours later saying my pinion nut had backed of my pinion and was only on torqued to 7 ft lbs. Did the guys on the floor take care of me probably. They were probably not happy to tell me it was covered under warranty. Everything was done right adjusted drive angle for lift and new tires, so in the end most of the time they don't go through hassle of trying to prove the cause. So miner mods done right to your vehicle will not void the warranty. If you use a good aftermarket shop to do any mods, they will always take care of their work before you even have to think about going to dealer. Hopefully this was helpful, sorry long post!!!
