Originally Posted by McSqueeb

I looked into this awhile ago after I had a number of people tell me about it. My understanding was that they can never void your warranty due to the installation of aftermarket parts. However, if they prove that the specific part in question was absolutely responsible for the mechanical failure, they can deny coverage at that point. A company can never require only a certain brand of parts to be installed in order to keep your warranty valid. This was only based off some internet research and talking to some people on other forums. I never really checked into the legality of it.