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Beginners guide to lifting your JK

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#1 · (Edited)
This is just to help with your lift setup. Some basic questions I see asked a lot on the forum ie. alignment, do I need XX, etc. Ill gladly go over and help choose a kit for your Jk. I am in not a suspension expert but know my way around. If something here is not covered ... Please ask. If I can't answer the question. I will do my best to find the answer for you. Don't be afraid to post here. the question/answer can help somebody in the future. GOOD LUCK !!!!!!

Tourque your boltsTourque specs for the jk can be found HEREon Project JK.

Death wobble: it's very important to properly torque your suspension bolts with the jeeps weight fully on the axles/tires. Not doing so can have the bushings in a bind and lead to problems.
ORE's explanation here
Death wobble is extreme. The front axle wanting to rip from the jeep, only stopped by coming to a complete stop. if not fixed can continue to reek havoc on your front end. The front axle is constrained by your upper and lower CA's and track bar. Usually a loose or bad Ca/bushing is not enough to for DW, any other lose or worn component for that matter. Add a bad track bar/track bar bushing or worn mount hole-all bets are off. Please see PlanMan's thread here on DW. Also the sticky on the grade 8 bolt upgrade. DW is serious and can cause a train reaction of broken parts if not fixed. Remember to always fully check torque periodically. Mark your bolts using a paint marker for a visual


Flighty/loose steering: If the jeep is lifted without caster correction, you might feel the steering to be flighty. The reason, adding lift height lowers caster. positive caster helps the steering wheels return to center. The stock Jk has around 4* caster and light compared to other vehicles. At 3" if height, you will likely want to adjust for more caster. Some of the cheaper lifts are for a reason. No caster correction is one of them.
Some fixes for caster angle
cam bolts (I do not recommend) Control arm drop brackets (AEV/Rancho/RC) Fixed length control arms Adjustable control arms Cut and rotating the C's or a aftermarket housing like Prorock or TF I just learned of folks using off set ball joints for caster. It's all new to me so I can't help you here Some info on caster here


Alignment:
Steering wheel not center You will need to adjust your steering wheel back to center using the drag link. If you have a Procal it can assist in doing so.
Toe Should be no change but ideally you want total 1/8 to 1/16 in.
DIY toe check
Camber If camber is out of spec you have bigger problems. Bent axle tube and/or C or possible balljoint issue.
Caster see above. Stock 4.2*

"Do I need control arms? "You have 8 control arms that are not adjustable. Adjustable CA's correct axle angles (pinion/caster and wheel base) Adding height the axles rotates up and in towards center.
Aftermarket control arms typically have better joints for less bind and clearanced for bigger tires. Longer control arms will also help the axle not steer itself as the axle articulates. If you look at any pic with a jeep flexing w/ stock CA's. The drooped side will pull in towards the pitch seem.
If lifted say 4", ideally you would benefit with all 8 arms to center the tires in the wells, pinion angle and caster angle.
"Do I need all 8 control arms?" No ... On a budget... Front lowers are commonly used for caster (adj'd longer then stock). Front uppers can be used as well (adj'd shorter then stock). Next I would add rear uppers for pinion angle (especially with a 2 door shorter rear DS)
Another option fixed CA's. One idea is to use fixed lowers and adjustable uppers. Great option and will save some $$$

one big misconception, after market control short/mid arms gain flex or articulation. This is not true. Flex joints/spherical joints/Heims used in aftermarket arms allow increased misalignment. This lets the axles flex easier/bind less.. Not add travel. Travel is ultimately your shock lengths

Rock Krawler mid arm

Teraflex fixed arm


long arms or short arms?
Long arm kits do not add articulation or flex. Long arms correct geometry and reduce operating angle running higher lifts. Issue being ... Unless its a custom install ...You're at the mercy of the manufacturer. Do your homework before choosing a long arm kit.
A good rule of thumb. Unless lifted over 4" of lift, running 12" travel shocks or coil overs, and 40" tires. You do not need a long arm kit.

steering wheel jerks left/right over bumps: This is known as bumpsteer. Bumpsteer is caused when the track bar and drag link angles are too steep, lengths, and geometry are off. As you go over a bump with one tire, the jeep jerks and sometimes will steer itself. Bumpy roads can be scary with a good case of bumpsteer. Bumpsteer is really is not a issue until up around 4", but the fix is a steering correction kit Raising the track bar & flipping the drag link is the ideal way to fix bumpsteer at higher lift heights -returning the geometry back to normal. Some kits do this similar using a drop pitman arm. I do not recommend using a DPA, it actually puts more stress the steering box. lowering the track bar reduces front roll center. one of the other benefits of a raised TB bracket is roll center correction.
SteerSmarts Extreme duty flipped drag link w/ Artec weld on raised TB bracket http://i1031.photobucket.com/albums...E-B42E-49D1-B52E-3357FB71DB05_zpsa8zx4yvm.jpg

Roll center/trackbar brackets adding lift height lowers the jeeps roll center. this can cause poor corner handling/steering. Raising the track bars at their mounting points will return the roll center to stock or higher. also keep the axle better centered during articulation.
oversteer/understeer Raising the rear track bar alone (front remains stock)= A positive roll axis/understeer. a little understeer is a good thing.
Raising the front trackbar alone (rear remains stock)=a negative roll axis/over steer. oversteer can cause handling to be unpredictable. you definitely don't want this.
Most kits in the 2.5+ range will address the rear. Notes:
- A shorter wheel base 2 door, oversteer/understeer will be more pronounced.
- The front track bar can not be raised without flipping the drag link or running a drop pitman arm (see steering correction kit)
- track bar drop brackets only purpose is axle positioning or axle center. usually supplied in cheaper kits.
Teraflex Raised track bar bracket http://i1031.photobucket.com/albums...C-7476-4FAE-8143-79A39FC43BC6_zpsii8crplo.jpg


Axles off center laterally: Adding suspension height will shift the axles. Front to the driver side and rear to the passenger side. A adjustable track bar is used to recenter the axle.
I usually recommend the front first. this will add a little rigidity to the front end and firm up the steering. A 2.5' lift will shift the axles maybe 3/8", not enough to be a concern in itself imo.
A rear 'axle side' track bar bracket will center the axle up to around 3" of height. raising the rear track bar will also improve roll handling.

Axles not center in wheel well (wheelbase) to return wheelbase back to stock - or better. All 8 adjustable control arms are needed. Lowers push the axles for/aft, uppers set pinion and caster angles.
Added on 5/9/16 This is a cool pic from Dirtman that shows how much wheelbase is lost w/ a 4 lift and factory CA's. The wheelbase does not change as much as one would expect .345x2 or .690 total both axles. Just proves you really dont need all 8 CA's under 3.5" of lift. Front lowers for caster and rear uppers for pinion on a 2 door.
http://i1031.photobucket.com/albums...7-F392-4732-B6FC-C1E9092B0AB0_zpsuqgouup3.jpg


When do you need driveshaft's? Adding lift height steepens the angles the driveshaft's operate at. Adding longer shocks will allow the axles to droop further. Disconnecting the swaybar links-even more. If the driveshaft doesn't contact the exhaust/crossover pipe the cv will eventually fail.
Some of the Fixes-Exhaust spacers/y-pipes/limit straps or a smaller ID driveshaft. There is no magic number that says you will or will not have issues at xx height, too many variables. So just make a habit of crawling underneath and looking for split boots and spitting grease. When you do decide to swap out driveshafts, adjustable arms are now very important to set proper pinion angles. **note** In some cases, running a taller lift and aftermarket Drive shaft, some will have to give up caster for pinion angle to prevent vibes, or worst case-the TC damage. Best bet here is a aftermarket housing with 10* separation. Or like mentioned ... Cut and turn the C's

Swaybar end links: most smaller lifts sold, only include longer rears. The stock rears are used in the front. The swaybar itself should be parallel to the ground at ride height +/- a few degrees. If running a longer shock you run the risk of inverting the links and causing damage. Plus drivability will suffer not extending the links. Quick disconnects are obviously another option.

shock lengths: Shock length is your axles downward limiting factor. adding height reduces downtravel running stock length shocks. The stock Rubicon shocks are around 8"in travel iirc. Shock extensions are a inexpensive way to add travel. they work but limit uptravel if the jeep is set up to utilize all of it [travel]. Most shocks list lift ranges ex. 0-2,4-6 etc. but you'll want to choose what works best with your setup.

Bumpstop height: every jeep is set up different. Choose your tires and shock size. Then decide on bumpstop size. Extended bumpstops limit uptravel . this protects the shocks, keeps tires from rubbing the flares, etc.
If running a drag link flip, the drag link away from the frame at full stuff. Theres other possible interferences depending on different components, so its important to cycle the suspension [full bump and droop] to determine BS lengths.
Take a look at this picture.
http://i1031.photobucket.com/albums...B-E54D-4360-AFF1-B6F4A06F21A9_zpshf5rgi3q.jpg
You can see i removed the yellow stop and fully compressed the axle. Look at how much shock shaft is showing (1"), or 1" wasted up travel. The idea is to maximize up and down travel utilizing every bit of shock travel.
I could do 2 things to reduce the amount of shaft showing.
1/ decrease stop 3/4 as long as no other parts contact each other.
2/ raise the lower shock mounts 1/2
Edit
So i decided to lesson the amount of bumpstop. First making sure nothing else got in the way for example drag link and frame.
The Rancho front shock can collapse 100% http://i1031.photobucket.com/albums...9-3597-494B-83F5-FA276181433F_zpsuxofnwvx.jpg
Leaving .5 shaft left showing at full compression.


Important note on lift height:
The general consensus is 2.5" is "safe" and you don't necessarily need CA's/TB's and all that good stuff. Yes this is true BUT. Aftermarket coils are designed not to sag under heavy weight. Some note that (listed heights are with a fully outfitted jeep). W/O bumpers, a winch, tire carrier, armor etc, it's not uncommon for a 2.5" lift to give you 1" or more in height.

general tire/lift height guide
** Backspace 4.5 or less
33's 0/1.5/2.5
35's 1.5 w/ flats/2.5
37's 2.5 w/ flats /3.5
40's 3.5 w/ flats/4.5

My goal here was to keep this simple. If anybody has any questions, please ask and I will do my best to help. others, don't be afraid to chime in. this discussion is for all.

Edit 11/1/2015

http://www.wranglerforum.com/f202/most-popular-lift-shock-setup-on-wf-1136938.html



Ken
 
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#2 ·
Thanks, Ken! Your tutorials ALWAYS teach me something new!

I appreciate the time you spend creating all the write ups you do for the benefit of the forum!

:Thanx:
 
#4 ·
Very good info for me. I am not looking at anything more than 2.5" but I have a 2 dr J/K and have even heard horror stories about a small lift. Thanks again.
 
#17 ·
I have heard of people welding add'l pieces of spring onto their spring in order to lift it, but this was my mechanic friend who lives way out in the sticks where nobody has any money. That is why I thought it might work the other way by cutting some off, but I wouldn't do it to anything that I cared much about how it would ride.
 
#23 ·
So since I'm finally doing my 3" teraflex lift w/ 8 flex arms and 35" ties looks like I should invest in an adjustable control arms and maybe a new drive shaft. Anything else I should look into? We're putting it on a 13 jk sport 2 door. Also I remember reading on here somewhere that when you lift ajeep that your tires move closer together due to the lift. Will an aftermarket driveshaft solve that problem or do you have to relocate the axles?
 
#25 ·
Control arms locate the axles in the wells along with set caster and pinion angles. Good there !!
Driveshafts if not soon ... Later. Just keep an eye on them. The Cv joint will split and shoot grease as a warning, I replaced my front but still running the stock rear on a 2 door w/ 3.5" lift.
 
#26 · (Edited by Moderator)
Thanks for all that info but me being a newbie looking just to make my ride look a little intimidating, I could use some guidance. I have a 2011 4dr JK i just bought. Everything is stock so far and I want to lift it and add larger tires, possibly change the stock 17" rims. I want it to be drivable in town but still look good. What do you recommend for rim size, wheel size, and lift? All the help is appreciated. I cant pour tons of money into this thing and want to get it right.
 
#27 ·
In your case less is better IMO. A JK can fit a 33" tire without a lift. The wheels (size does not matter) should have 4.5 or less back spacing.
You can opt for a small leveling kit that will remove the factory rake and lift the rear a bit. Or a 2.5" BB. Both will get you a little more clearance and not affect geometry or the ride much.
 
#30 ·
I never had my numbers on the last jeep but I'm sure it was off too. It drove fine after the 2.5 for about a year or so but I wheeled it and smacked on some 35s and that's when problems started showing up with steering. Hard to say which got er there.
 
#32 ·
Yes and they were really great pieces. In retrospect, I should have just waited because alas...I traded the jeep in about 2 weeks later and it was really just money down the drain. If I had that $400 or so now, I would be getting some SRC sliders or a new bumper on the 13!

Of course 12 + sets of tires on the last jeep wasn't cheap either. :banghead:
 
#33 ·
Hi there, I was just wondering... is reprogramming using a procal or similar device necessary when adding 2.5" lift and 35" tires for the Jeep to be able to run correctly? (manual tranny, and I understand speedo and tpms would be out, but is there anything computer-wise that would prevent me from traveling to a shop to have the programming done?)

Do most guys buy a procal or have a shop do the reprogramming?

Is a procal something that would be used more than on one occasion if there were no other suspension/driveline/tire size changes?

Thank you
 
#34 ·
Hi there, I was just wondering... is reprogramming using a procal or similar device necessary when adding 2.5" lift and 35" tires for the Jeep to be able to run correctly? (manual tranny, and I understand speedo and tpms would be out, but is there anything computer-wise that would prevent me from traveling to a shop to have the programming done?) Do most guys buy a procal or have a shop do the reprogramming? Is a procal something that would be used more than on one occasion if there were no other suspension/driveline/tire size changes? Thank you
Procal is to set for tire diameter am speedo/odo plus some other things. A dealership can do THE Spe/odo but it will cost you. Yes you can keep using it but I believe it can only be used on one jeep at a time.
 
#37 ·
Dumb question I am sure but I am new to the jeep world. Is BB some body lift?
 
#42 ·
AEV

Google "AEV correction brackets" on the AEV site there's a PDF for the instructions which shows the diagram.

There's 3 holes on AEV's brackets. The 2.5 hole is set to give a little caster bump. The 4.5 (top) hole is set to not allow as much rotation for caster. Caster should remain the same for 2.5 - 3.5 and 4.5 being the holes are not set in the same locations. I believe AEV targets 4.5 or so.

The Rancho brackets only have one hole. Iirc is the same as AEV's middle 3,5
Not having the other 2 holes the caster will change at different lift heights.

Rancho can correct me if in wrong, but I believe (like stock) as you lift caster decreases. So... At 2.5 you will have more caster then somebody at 3.5 (me -4* ish)

Not a bad thing because the higher you go caster can actually hurt you. 6* at 2.5 is high but ok. At 3.5" the driveshaft angle would be pushing its limits.
 
#45 · (Edited)
Thanks for all the details. I'm guessing I would use the 2.5" hole on the AEV bracket and that would hopefully bring me back up to around 4 something degrees of caster. I actually like the design of the Rancho brackets better, but am afraid they may be too much for my 2.5" of lift.

How long will it take me to install the AEV brackets by myself? Just read the instructions and they said to work on one side at a time. Did you have to pry your exhaust out of the way to install them? That sounds like a pain.
 
#44 ·
Including tires ? $3000 is a good chunk of change. Not a bad thing but a lot to spend for look over function. Is the 3k just for a lift, what size tire and how high you want to go?
Fwiw .. A 35" tire will fit comfortably under 2.5"
A 33" will fit with no lift at all.
 
#48 ·
I was doing some reading and saw a reference to a 2" front lift for a 4 dr jk and with the 0 rims they could fit 34" tires and level the ride for a weekend warrior like my self . no big mud or rock climbing.. Please help :awesome:
Why not go with a 33" w/ no lift ? OR.... i think what you saw was a leveling kit using spacers. Usually 2" front and 1" rear. Enough to level the jeep and provide a small lift.

Assuming 0 offset ? You want a wheel regardless of diameter to have 4.5 or less back spacing.
 
#49 ·
SO I keep going back n forth on this and can't decide. I see from a lot of the more experienced jeepers that you can run 33's (in my case I was looking at DT so I guess closer to 32.5) without a lift? But if I did want to do some mild off-road i assume a small lift would still be recommended?

Also keep reading that most lifts are "over" (2.5 is really closer to 3, or the TF 1.5 coils are closer to 2 front and 1 rear) to compensate for weight?

So confusing!! How much weight to lower a lift back to its advertised height?

If I want DT 285/70r17 with the right wheels, front and rear bumpers and rockers would a TF 1.5 perf coil lift and rancho 9000's still be enough lift? :pullinghair:
 
#50 ·
Yes coils are rated for weight. TF offers a 2 and 4 door coil which will put you closer to advertised height. RK does not .. So a 2 door averages about 1" more. Regardless a light weight stock jeep will be higher.

Most kits remove the factory rake and that's the reason for more height up front.

33's will work as long as the wheels have 4.5 backspacing or less. Will it rub heavily flexed ? Most likely yes. A small leveling kit will help.
Another option is flat or trimmed factory flares.
 
#51 ·
Yes coils are rated for weight. TF offers a 2 and 4 door coil which will put you closer to advertised height. RK does not .. So a 2 door averages about 1" more. Regardless a light weight stock jeep will be higher.

Most kits remove the factory rake and that's the reason for more height up front.

33's will work as long as the wheels have 4.5 backspacing or less. Will it rub heavily flexed ? Most likely yes. A small leveling kit will help.
Another option is flat or trimmed factory flares.
So is their a "rule of thumb" as far as X amount of added weight will reduce height of lift by Y amount? Or is it just put lift on, add weight, if its to low add more lift? I was trying to stay as low as possible so I didn't have issues but still have some flex off-road?

Kinda thinking the TF 1.5 mite not cut it with the added weight?
 
#53 ·
Here's the quick and dirty :)

Caster-Adding lift height lowers the caster. Caster angle is a imaginary line that crosses through the ball joints. Positive caster would be a line drawn forward of the center line w/ the lower balljoints I front of the upper. Caster puts a downward force on the axle making the easy for the steering wheel to return to center. Stock Jk has around 4* caster and is light compared to other models. Tj for example FSM shows around 7*
A 4" lift, you might see up to a 2* loss in caster. Less caster (closer to 0*) can cause the overall steering feel to be light or flighty at speed.
At what point you want to address it is up to you. Most people will agree that, at 3" you will likely want to.
Fix/options are Cam Bolts:nonono: Drop Brackets, longer/shorter Fixed Control Arms, Adjustable control arms, cut and rotating the C's or a aftermarket housing like Prorock or TF.

Steering wheel of center. "Why is my traction control light flashing ?" Easy fix. Adjust your steering wheel back to center using the drag link.

Toe-no change but ideally you want 1/8 or 1/16 in

Camber-no change. If camber is out of spec you have bigger problems. Bent axle tube and/or C or possible balljoint issue.

Control arms (short) if you opt for arms, get adjustables. Upper or lower, it's your choice (they do the exact same thing( just backwards from each other). front lower and rear upper will give the minimum adjustability for pinion/caster if on a budget of working in steps. If you find that you want to move an entire axle forward/backward in the wheel well, you will need both upper and lowers. Having all 8 arms is ideally what is needed for caster/pinion and wheelbase.

Bumpsteer- bumpsteer is not a shimmy or beginnings of DW. Bumpsteer is a condition caused by the track bar and drag link no longer operating in the correct arc. As you go over a bump with one tire the jeep will kind of steer itself and you will feel it in the steering wheel. Fix - Highsteer kit. Raising the track bar and flipping the drag link is the best way to fix this by returning the geometry back to normal. There are other ways to go about this but not recommended.

Roll centers. Front and rear as the body is raised the roll centers are effected causing sloppy handling around corners. Most kits in the 2.5+ range will address the rear only which is fine. Ideally you want the front and back to match.

Axles off center (track bars) can be as much as 1/2" (maybe more) at 3-4".
TB brackets will lesson the angle and somewhat center the axles. In most cases a adjustable track bar (F/B) is needed to return the axles back to center.

Driveshafts- Adding lift height steepens the angles that the driveshafts run at. On the shorter wheelbase 2doors (esp the rear) they get steep quick.
Adding longer shocks causes the axles to droop further, disconnecting the swaybar links-even more. If the driveshaft doesn't contact the exhaust crossover pipe the cv will eventually fail.
Fixes-Exhaust spacers/y-pipes/limit straps or a smaller ID driveshaft.
There is no magic number that says you will or will not have issues at xx height, too many variables. So just make a habit of crawling underneath and looking for split boots and spitting grease.
When you do decide to swap out driveshafts, adjustable arms are now a must .The joints on the aftermarket shafts like different angles then the stock shafts. **note** In many cases, running a taller lift and aftermarket Drive shaft, some folks who have to give up caster for pinion to keep the TC from exploding. No choice but to give up drivability for pinion angle for a safe u-joint angle of operation. Or drop $5k on a aftermarket housing with caster built in.

Death wobble - lets hope not :D

The general consensus is 2.5" is "safe" and you don't necessarily need CA's/TB's and all that good stuff. Yes this is true BUT. Aftermarket coils are designed not to sag under heavy weight. Some note that (listed heights are with a fully outfitted jeep). W/O bumpers, a winch, tire carrier, armor etc, it's not uncommon for a 2.5" lift to give you 1" or more in height.

This is only the basics. So next time you see a sweet 4" lift for $300-$400 with only coils shocks and maybe cam bolts :eek:-you might want to think about it. There's so much more involved.



Comments, feel free to ask questions? I posted to help folks understand :thumb:
You obviously know your stuff......so here is a quest for a new jk owner-previously had a CJ and a YJ. I noticed while offroading all this computer aid stuff really effects just good ol fashion:worthy: wheel spin-Any suggestions? Also when reversing even in a simple incline like my drive way there is alot of resistance-could this be the hill assist?
 
#54 ·
I'm not really familiar with HSA having a 07 but iirc and can be shut off or learn how to use it. It can be very useful off road but annoying on. ESP can be shut off in 4 low for wheel spin in sand or when needed. Some still have issues and wire in a toggle switch or the steering wheel dance to defeat completely.
 
#56 · (Edited)
:wavey: nothing wrong with spacers. You are going to want longer rear sway bar links (stock rear to the front) I recommend longer shocks or extensions and bumps top extensions.
Edit: realized you are driving a Tj. Not sure if the stock sway bar links will work on the front like the Jk. Might want to look into that.
 
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