I'm thinking about putting a 2.5" lift on my new Unlimited. Does this have any effect on the warranty?

 

In a word, no.

 

Above statement is correct..... but...
Some dealers do not like lifts at all, some don't mind them..... the only way a dealer could void warranty is if they can prove that the lift was the cause for the problem..... and the main word here is "could"
If you change the suspension components, then the suspension part of the warranty would be voided but the rest stays intact....
Tricky situation...

 

I paid more than a offroad shop or do-it-yerselfer, to have it done at the dealership, but that was to keep the warranty up. It was interesting at 'Customer Appreciation Night' to hear the dealer tell an experienced lifter that his spanking new jeep 'could' be out of warranty...if there was a dispute that caused them to bring the Daimler adjuster in. They limit the 'look the other way' disputes to 3" or lower.

Also took my first extended (non-chrysler) warranty back because it was DOA due the the Jeep being 'modified'. Make sure you read the warranty. It was not going to cover anything because the lift was not a Chrysler recommended adjustment.

My service guy tells me the Chrysler Maxicare extended warranty is 'better'.