Haven't seen any responses yet. I for one am a bit confused. If you're talking about an XJ that might make sense. They are a subframe vehicle. I think pretty much all other Jeeps have full frames. By "Y" and "T" frames or axles I don't know exactly what you're refering to. No axle can have anything more than what it takes to transfer power to a wheel. All trucks have full frames. I've installed literally hundreds of lift kits (mostly on trucks) in the last 20 years and I'd be more than happy to answer your question. Just need to know a little bit more of what you're talking about