One additional note. Toyota will also balk at warranty repairs for problems they may say were CAUSED by the lift. This is a bit of a gray area, and will only effect a few things. Example, CV axles or boots up front, because of the increased angle they will be at with the lift installed. A good shop can tell the difference, and will try to work with you.
x3 or whatever number we're up to by the time this posts... if you change the suspension, it's pretty much common sense what will/won't be warranteed (or what you can expect)... for example, some dealers will conduct all the routine maintenance on your suspension, even if it's aftermarket, some will see that it's not stock and not touch it... as a general rule from my local dealership, they don't do any work on non-toyota parts, which makes total sense.... that being said, the Mag-Moss act protects us from a totally voided warranty... I wish I remember who said it, but the biggest piece of advice I've gotten from these forums with regard to warranty is this. "A warranty means that the company will fix it IF IT IS DEFECTIVE, NOT if you break it".
Though I don't have it in writing, my dealer said as long as the lift isn't over 3" it is acceptable but anything determined to be caused by the lift is not covered. . . so basically, same as what Layonnn said.
my dealer said they expect modifications and will even install lifts and do modifications for you to ensure it is done correctly....but nothing extreme. 3" lift is limit of their liking.....33" tires are their limit as well.
I am building the relationship now and will see how it goes and whether anyone in back is wheeling a Toy or not....they keep technicians separate from customers...so pretty tight operation but getting there.
To be on the safe side, I had my OME left kit installed by my Toyota dealership, who stated in writing that the installation wouldn't void any warranties of the FJ itself. Obviously, the dealership wouldn't have installed it if there was a potential for damage to the rest of the vehicle.