Awesome video, thanks for sharing. Here is my understanding of issues that can pop up. My knowledge is just from reading through threads trying to figure out a coil lift that won't break my driveshaft boot. I think i'm right about all of it, but I could be wrong.
I would highly suggest checking out this link too by Matador
If you're doing a lift it is a good idea to consider changing out some of the stock bolts that come from the factory a bit too small. They can eventually lead to death wobble.
GENERAL LIFT FOR TIRE SIZE
32" is the stock Rubicon KM tire size. Its common forum wisdom that 33" can be run with no lift. Is that with the swaybar disconnected also with no rubbing?
NOTE:With tires you need the proper backspacing from the hub so that you won't rub when turning. That means spacers (badish idea) or new wheels with proper backspacing.
- 2" Lift = 33" maybe 34" tires
- 2.5" Lift= 35" tires
- Over a 2.5" Lift it gets expensive quick for the reasons below.
This link is a good one for a general idea what lift you need
LINK>DEFINITIVE WHAT SIZE TIRE/Wheel/SPACER/BACKSPACE THREAD - JeepForum.com
COIL VS BB VS BODY LIFT
Coil lifts are better because they will give you more flex off road. They are going to be a major change in feel for better or worse. They cost a bit more. They are better if you're going to add a lot of aftermarket steel items/winch.
BB/spacer/coil-puck/leveling lifts will keep your stock feel and give a much more accurate amount of lift, especially with 2DRs close to stock weight. Rough County is supposed to make a good good kit for cheap. For the most part all these type of kits are the same. You can either go stock shock extensions, or go with longer shocks. I wonder if longer shocks gives just a bit more flex? Then they will likely give you a bracket to lower you break line. They will also give you a longer sway bar link to stick on the rear, and the rear will go to the front (2.5" lifts). Rough Country gets recommend for the most cost effective BB.
Rear Shock Extensions
The factory spring stiffness will determine how much they will sag if you add extra weight (bumpers, etc)
Originally Posted by rics1997
Not sure what all parts your are talking about but the coil spring themselves should fit. What you need to do is see if it is worth the switch is check the two vehicles coil spring numbers.
Your springs will have a tag with the stock number on them. The last two digits are letters; Ignore them. Look at the last two numbers. The JK's coils run from numbers 13 to 19 on front and 54 to 60 on rear with the lower the number the weaker the spring.
Example, mine were 14 on front and 56 on rear.
I switched mine out with 19 on front to 60 on rear and got 1 1/4" lift. Many have claimed as much as 2" lift but it has to do with what stock coils they had and the fact I already had extra weight on my Jeep with new bumper/winch and heavy recovery kit in back.
These seem to be only used to correct issues with suspension lifts. As is noted in the video it can be added to solve driveline issues. Its a puck stuck under the body bolts.
WHAT MAKES IT A HARD DECISION FOR COIL LIFTS
Coil lifts will almost, if not always, give you more lift than advertised if you don't have extras like bumpers, a winch, body armor, etc. At 2.5 inches (actual vs advertised) a lift doesn't need much adjustments. As you go higher the expense starts to go up exponentially.
Issue 1) With a larger lift you start needing an adjustable track bar to center the axle (side to side), and adjustable lower control arms to adjust caster. Without longer Lower Control Arms (LCA) you going to give up wheelbase.
Issue 2) On the 2012+ JK's with more than 2.25" of lift the driveline will rub the exhaust cross over. Check out this video
TeraFlex Install: 2012 JK Updated Exhaust Spacer Kit - YouTube
You can add a teraflex exhaust spacer. These will rub slightly on many engine/tranny skids. You can add some washers to shim the issue. With 4drs you can also add an aEf y pipe as a more elegant alternative.
Issue 3) With all JK's you can only lift so far before the factory cv joint on the front driveshaft, at the transfer case side, will be an issue. It has a rubber boot (at the very end not the one in the middle) that will rub at somewhere around 3". I REALLY wish I knew an exact measurement before that rub starts on a 2dr. I think 3" but i'm super iffy and that sucks. After the rub becomes a tear the driveshaft is shot. If that happens a double cardan driveshaft can be added which allows more angularity. I'm going to guess that's around $600+. I don't know at what added height the rear driveshaft becomes an issue
. That also would be nice to know.
This is a picture of the issue. You can see it will rub if the angle is too much.
It's also not great for the front drive shafts cardan u-joint to have too much angularity where it meets the differential (pinion). That will end up speeding up the lifespan on the u-joint.
Issue 4) Teraflex tells you that you need wheel spacers with their 2.5" coil lift I'm assuming that would only be for wider tires and 35s with the stock wheels. I'm not totally sure. There are 2 kinds of rub. One is going to far up, front or back. The other type is created by not having the right backspacing on the wheels which will rub when turning.
Issue 5) Too much lift and awesome becomes roller skates for wheels. To fill out those gaps= bigger tires=tire carrier=regear=less mpg=you broke with a bad ass Jeep.
I'm not sure whos jeep this is. You can just call him "That Guy."
Here is pictures of the LCA's and Body Bolt locations