JKUon37s

What gears are coming with your jeep? If you have 3.73's I'd stay with 35's unless you plan to regear. I'm running the stock rubicon 4.10's with 37's and I would like to regear soon. I take mine offroad so that's why I didn't go with the drop brackets. If I didn't take it in the rocks I would get the brackets. The ride gets a little harsh on square edged bumps with 4" of lift and stock control arm placement.

Dlampe

I ordered the 4:10's. I almost didn't so I could regear to 4:88's but I have had no trouble with the 4:00's and my current 35's. I do take it off road as well but it comes down to priorities. The Rancho brackets seem to be a little beefier and don't seem to hang down as much as some of the others.

I have a set of 35's and a set of 37's in my shopping cart right now. There is only about $180 difference in price. It is very tempting but I'm not sure it would be smart.

TheDirtman

The "best lift" is the one that fits your needs and your budget. There is no "best lift" you can throw out there for everybody. If you like the look of space between the fenders and tires look at flat fenders as they will give you the wheel clearance and look of around a 3" lif t without messing with the suspension and steering. 2" of lift and flats is plenty to run 37's if you have proper wheel bs and correct size bump stops. The teraflex kit you mentioned is one of the most complete kits on the market and if you feel that is what you need and you are satisified with the cost then go with it but remember there are more then one way to skin a cat. If you are really going to run 4"+ of lift, for what you describe you are doing with the jeep, I would go long arm or use drop brackets for geometry correction.

With the geometry, if you can keep the links as paralell to the ground the better, avoid steep angles in control arms, track bars, and your steering links. All these links travel in an arc and if you do a little geometry, you will see how much more axle shift and how your geometry becomes compromised as you go higher in lift. You will also find with taller lifts and longer shocks that you will get more axle rotation and shift and you will have to take that into account when figuring clearances and wheel back spacing. You can also download 4 link calculators to see how different heights will affect your suspension geometry. All most every 4"+ lift kit that you can buy ignores the affect of axle shift and rotation and things like anti squat and roll center.

I realize that suspension geometry is hard to get in your head unless you are getting a lot of hands on experience but when you finally get how things move in an arc and how when you change the length of one side of a triangle that everything else changes it will become second nature. It is all just basic geometry.

Coils, I think people get way too hung up on coils. Everyone seems to be swapping them out every time one of the manufactures comes out with their "new" coil. Tripple rate seems to be all the rage now. Do you need tripple rates, will they give you the best ride? It depends on how you drive and your needs for compressed and extended lengths. These things are important if you are building a super flex rock crawler but you will see little benift from a daily driver that hits mild trails and is running 10" travel shocks. As far a ride is concerned people should care more about he coil rate of the coils and not if the are a dual or tripple rate as the rate will determine the quality of the ride with the paired shocks that are tuned for the coil rate and the type of driving you are doing.

Tires are another thing that get a lot of concern and hype. Get the tire that fits your needs and budget. C,D, & E rated tires are all built for different applications. E rated tires are built for heavy duty trucks that haul a lot of weight and heavy trailers, they are not built for jeeps and really should be avoided. The whole E rated tires are better for off road because they are harder to cut may be a slight issue for a select few but a C rated tire will be cheaper (less material to build), give you a better ride (lower psi), and will hook up better off road when deflated vs a E rated tire since the softer (fewer belts) sidwall will flex more and mold around obsticals better. The softer sidewall will also give you a bigger footprint when aired down and side lugs will grip better.

I would never run a E rated tire off road as they are not built for that and if you more of an extreme rock crawler you are probibly going to be running a heavy duty biased tire for maximum traction off road.


As far as front caster is concerned, you will not be able to regain factory caster without a new axle housing that is built for 4" of lift, cut the tubes and spin them, or use offset ball joints as mentioned. Just using control arms or drop brackets will not get the caster back for you as it will become a balance of drivability and vibration due to u-joint angle on the driveshaft.

For tires 35's would be the biggest tire I would run for a daily driver that may see some mild trails from time to time. You can run them fine with the 4.10 gears and mileage will not suffer that much and you should be able to tackle most of the trails at Badlands with that set up.

Good luck with the build.

Dlampe

Thanks Dirtman! I really appreciate your input. As I mentioned, I read your suspension article. Well actually I had to read it a few times but it was very helpful. I know there is not a "best" lift but there is a best for me given what I'm trying to accomplish. I think a good 3 inch lift with 35's is the best option. I just needed to understand why the 4 inch and 37's isn't. The replies on my thread as well as the other threads has helped tremendously.

I don't want to cut my axle or get a different one. That's what is needed to run a 4+ inch lift correctly. That takes the 4 inch lift off the table for me. I know I can run 37's with flat fenders in the future but I don't want to run flat fenders now. 37's with a 3inch lift and factory fenders won't clear (as I understand) without over sized bump stops to limit travel which is really counter to what I'm trying to accomplish. I also don't want to change the 4:10 gear ratio right now which would be needed to run 37's correctly. I could use a body lift to gain the clearance but that still leaves me with less than ideal gearing. A BFG a/t in 37 weighs 69lbs vs a Nitto at 90lbs. Maybe that's enough to matter and the 4:10 gears might be OK, I don't know.

This whole process helps me realize what I'm willing and not willing to do. That has set parameters that I need to stay in when I'm building the "best lift" for me.

TheDirtman

4" of lift and 37's basically comes down to cost. Properly done you are replaceing nearly everything under the jeep to correct the geometry as much as you can. Ride quality and stability with running 37's on factory axles with a big lift is also a factor. Tire diameter has more to do with gearing then weight, however all weight that you add to the jeep has an effect on performance. Improper gearing with heavy tires will put a lot of stress on your entire driveline.

As mentioned a 4"+ lift does not require a new or cut axle but you must realize you will not get the factory caster and steering feel will not be attainable. If you can stand the light steering feel you will get from loss of caster then you are good. It is all personal preference.

As far as lift heights most people don't realize the how the differences in heights and shock length translate into axle shift. Going form no lift to 2" of lift with a 10" travel shock is much different then going from a 2" lift to 4" with 12" travel shocks. You are only raising 2" in each example but you get much more axle shift and rotation from the 2" difference in the 4" lift when using short arms due to the travel along the arc. The higher to go and the more droop you have due to longer shocks the more extreme the misalignment in the suspension you will get during articulation.

Fine tuning is the key to properly setting up a suspension. Most people do not do this. They buy a kit and install it. Lift manufactures build a lift to try and fit a generic set up with different weights and for a specific shock travel. If you are piecing together a kit and using differnt length shocks you will have to account for that difference due to the travel. If you are looking to max out your articulation you will need to be able to cycle your suspesnion and understand how to set up bump stops and how to size shocks to fit your application. This is very time consuming and can be frustrating, adjustment of bracketry or body trimming is often needed to maximize the articualtion. From your discripion of what you do with your jeep I don't see the need to grab every bit of travel you can get.

DannyMalkin

Dirtman is great, listen to him

Dlampe

I agree. Dirtman, Plainman and Maertz really know their stuff and I'm sure it's from learning it the hard way. I 'm thankful that I can learn from them and do it "right" the first time. I think I'm going with that Mopar lift I linked to earlier. That should get me a solid 3 or maybe 3.5. The drop brackets from Rancho will set the angles correctly with the front control arms. I can use my current Coast 1310 front shaft with my JKS track bar. Will I need a track bar bracket to raise the axle end?

MOPWR2U

I would be surprised if you need to re-use your JKS track bar. That Mopar lift should have track bars covered.

TheDirtman

It will depend on the true amount of lift you get and the quality of the ride. You will only raise the track bar mount on the axle if you are doing a drag link flip. You will be right on the line to run a drag link flip or not as you will loose up travel in the suspension by moving the drag link on top of the knuckle and a raised track bar bracket will be closer to the frame. On the rear axle you should do a raised track bar bracket that is at least 3" higher then the factory mount. I would not use the type that simply bolt on the factory bracket as the extra leverage tends to break the welds and many have seen the backet tear off.