Ok my problem is that I want a 3"lift with 35" tires and I have a 4 dr unlimited with automatic transmission. Everything that I've been researching is telling me that if I go with the 3" lift then I'm gonna have to change out driveshafts at least on the front because it will tear the boot. I don't want to change driveshafts or I should say I can't afford to change out driveshafts. So my question is, is it true that I will need to change driveshafts with the 3" lift, if not then problem solved. However, if it is true then could I possibly go with like a 2.5" lift with a 1" body lift and be ok without changing driveshafts.

Also, how much difference in MPG is there between the 33"and 35" tires? If there is not much difference then that is why I am opting for the 35" tires instead.

My main goal here is to try and get the most beefyest look I can without having to break the bank by changing out a ton of stuff and at the same time keep a good quality ride and decent gas mileage.

 

The problem isn't the lift height, but the amount of flex you will get out of the lift. Even with a Teraflex 2.5" and shock extensions I had this happen on my auto transmission.

 

yes, on a 3" or greater lift with an auto, when you flex the front end the axle will move enough to allow the rubber boot on the driveshaft to contact the auto tranny pan and it will tear, allowing the grease to fly out. the rubber boot is non servicable so the only way it can be fixed, is to replace it. Aftermarket shafts dont have the boot and are a smaller diameter so they wont cause this issue. You wont need a new rear at 3" of lift on an unlimited.

I would go with 35's if i was lifting a 4dr 3". 33's would look small IMO with that setup.

 

I concur. It's the flex that you get out of the lift that will cause your drive shaft boot to tear. So, if you're not going to off-road it or flexing it out, you should be able to put the lift in without tearing the boot. But, if you do any sorts of wheeling and flexing out, chances are high that you'll tear the boot. I did on the first trip after lifting it. I have since replaced the front driveshaft with a Tom Woods shaft.

 

It is true that 2.5-3" of lift is roughly the threshold that triggers the need for other mods. But also consider the following:

- The effective lift created by any kit is not always equal to the nominal amount on the product name. Usually it is more.

- The FAQ contains great information on this subject particularly regarding the differences between 2 & 4 doors and auto and manual trannys. It is the best place to start before you read or start any threads because the information there is as unbiased as possible, contrary to many of our opinions in most of the threads.

- Unless you install a radical lift, the driveshafts are not going to disintegrate after the first revolution. The longevity of the stock DS will highly depend on the amount of lift and how much you flex the suspension.

If want significant lift and you can't afford DSs right away then drive moderately off road. If you don't want to change the DS in the long run, then stick with 2.5" kits. The body lift is not ideal in general, but it is a good way to get more partial lift (the chassis stays behind) for tire clearance and looks and minimize the need for additional mods.

It may be confusing at first because there are a lot of facts and opinions to assimilate at first, but the more you research this topic you will find a setup that fits your taste, budget and reliability needs.

 

Thanks alot. I appreciate all the help. Hopefully I'll get it built soon and start posting some pics.

 

See post #6 for a few more preventive measures...

https://www.jk-forum.com/forums/modified-jk-tech-2/driveshaft-vs-skid-plate-102041/