When I bought my jeep it came with a lifetime powertrain warranty. At what point will the dealer not honor this warranty with doing modifications to my jeep??

 

Whenever possible.

 

Or, whenever you put in a warranty related claim!

 

I live in a small town and my dealer is really good. This varies dealer to dealer. I have never had my dealer refuse a warranty repair or even question it, but others experiences may be different

 

My hometown dearler has a motorsports division and, at least basically, understands the sport. Technically they have to prove that the modification caused the failure of the component. So, in theory, 35" tires would not void the warranty on the stereo, but if an axleshaft fails its all you.

That being said, read the sticky on this forum regarding WOL's warranty crisis.

As far as the lifetime warranty goes, I wouldn't count on it at all. That was a bad PR idea, and now that FIAT owns the name, I bet they try to get out of it at all possible times. Just an oppinion though.
Hope it helps.