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My thoughts on lifts.

47289 Views 61 Replies 26 Participants Last post by  lanceberens
You see it posted almost everyday “new jeep owner, what lift?” and we go thru the motions of what are you going to do with it and what tire size. You also get endless posts of “I am running ***** lift and it is better then stock” along with a poser shot. I still to this day do not understand how someone can see the suspension on a rig from 25 feet away in a photo. Those two important questions to consider when doing a lift, tire size and what you plan to do with it are the keys to setting up your suspension. I am keeping these thoughts mainly on the bolt on kits for the JK.

Most of the op’s have the misconception that somehow a bolt on lift will give them more articulation or “flex” and that a lift will make the Jeep more capable off road. Most will not and some will even make them less capable in some areas when compared to the factory suspension. Reduced wheel base, coil unloading, and low roll center are just some of the things that can happen with an incomplete bolt on kit that will be detrimental to off road performance. Play around with a 4 link calculator if you want to see how much your lift is messing with the actual geometry of your Jeep. The higher you go the worse it gets too.

While a 4” lift will increase the amount of up travel you have if you don’t run a longer shock you will loose 4” of down travel for a net increase in flex of zero. Add a 2” bump stop to the above example and you just lost 2” of flex vs the factory suspension set up. I think most people have this misconception of increased flex due to the fact they usually add larger tires when they lift and that is where they are seeing the improvement off road.

Many manufactures will use names with the word flex in them to describe their arms, lift kits, or joints. These are just marketing terms and do not flex any more then another bolt on kit from other manufacturers. The “upgradeable lift” is another myth made up from the marketing team. Any lift out there is upgradeable, there is nothing special about one that advertises it as one. The term "mid arm" is also a term that is made up by a marketing team, in reality it is the same basic length as the factory arm. They use this term in comparison to the tj control arms that were really short.

I believe that a lift is needed to gain clearance for increased tire size. It can also be used to gain some belly clearance for break over angle (mainly on the 4 door) and for better approach and declination angles, although I would argue that tires should be used for these issues instead of just lifting. The bigger your tires the more total ground clearance you will have as well as improving your break over, approach, and declination angles. I understand that other factors will come into play with large tires, mainly gears, wheel bs, and fuel economy.

If you were to compare two Jeeps, one set up with a 4" short arm kit on 33" tires and one with a 2" lift and 37" tires with trimmed fenders the one on 37's, if properly geared, would run circles around the higher lifted Jeep. It would climb better, clear bigger rocks, be more stable in off camber situations, and would handle better on road due to the lower center of gravity. Both Jeeps would be the same height overall.

For me the thoughts on lifts would be to start with trimmed or flat fenders for 33’s add a 2” lift for 35’s a 3” lift for 37’s 4” for 40’s
Expect some trimming of pinch seams as your tires get larger in size.

Wheel bs should be included in the discussion as well to maintain full steering. Wheel back spacing for the previous lift recommendations on factory width axles.

Net max back spacing:
5.5” for a 33x12.5
4.5” for 35x12.5
3.5” for 37x12.5
1.75” for a 40x13.5



The Parts:

Coils:

Coils are what gives your Jeep it’s ride height, in its most simple form a lift is just longer coils or a spacer placed on top of the coils. The benefit of a longer coil vs a spacer lift is that it will have a bit more travel built into it so you can droop a bit more and run a longer travel shock. A dual rate coil is made with a light coil rate section that will compress at ride height and allow for an even longer throw at full extension allowing for the potential of increased articulation. A coil that minimizes lift and maximizes unloaded length will give you the most benefit for increasing flex and off road performance.
One drawback from a coil that is really long is unloading that occurs on a steep climb or decline when the coils push the jeep away from the axles and give you the possibility of flopping onto the roof. Limit straps and suck down winches can help with that problem. ORI struts have a built in feature that eliminate this problem as well.

Shocks:

Shocks control the compression and rebound of the coils, quality of the ride, and the upper and lower limit to a suspension. To increase articulation, total travel is what you are looking for. Typically for 33”-35” tires you will be looking at a 10” travel shock. With 37”-40” a 12” travel shock will do. These are for bolt on kits, if you want to get adventurous and are willing to cut and weld 14”-16” are doable with considerable effort.

When running a longer travel shock you will have to take into account the rotation of the axle when one wheel is drooped and one is stuffed. The stuffed wheel will travel farther into the wheel well and you will experience more axle shift where a driveshaft may make contact with the fuel tank or oil pan.



Bump Stops:

Bump stops are there to keep your tires and other suspension components from rubbing on fenders and the frame. They are also used to keep shocks from totally compressing which can potentially damage them. When adding larger tires or doing a drag link flip you will need to add bump stops to keep things from rubbing. You can also trim fenders or notch the frame to gain extra up travel. Remember when adding bump stops you are limiting your up travel and are reducing your flex. Trimming fenders or running flat fenders is a good way to increase flex if tire rubbing the fenders is your limiting factor vs running longer bump stops.

Limit Straps:

Limit straps limit your down travel and can reduce your flex. However If set up properly the limit strap will prevent your shocks from totally extending, potentially damaging them, and can actually allow you to increase flex by overcoming the limitations of other components such as the drive shafts. By placing a limit strap at the differential you can limit the angle of the u joints or keep a driveshaft from making contact with the exhaust cross pipe while still allowing more droop at the wheels so the axle can rotate over obstacles. I have not seen a single lift that offers limiting straps, though they should be in every kit over 3” at least at the front driveshaft.

Sway bars and links:

While most of you disconnect your sway bars when off roading, (I don’t run them at all but my set up is far from a bolt on) should you run off road with them connected you run the risk of flipping your sway bar forward if your sway bar links are too short. This will lock up your steering and will likely bend stuff. They should be sized so they are +- 5 degrees from level. I would error at the +5 if it were me as I have flipped mine a couple of times when I over extended the front end.

Disconnecting the links will give you more potential travel in your suspension but will also make it less stable in off camber situations. After market sway bars like the TeraFlex duel rate or the Currie anti-rock will give you extra stability while having a softer twist rate for articulation.

Track Bars:

Track bars keep your axles centered on the Jeep. As you articulate your suspension the axle will shift from side to side. When you droop the front the axle moves to the driver side. The opposite happens on the rear. As you lift the track bar becomes more angled and due to that angle will shift more then a stock or level track bar. The track bar also determines your roll center. This is a line drawn thru the center of the front and rear track bars to determine how the vehicle will roll on its suspension from side to side. Think of a top heavy feeling from a low roll center. Raising the rear axle side track bar bracket will increase the roll center and make the Jeep feel more stable during off camber situations and on road cornering. The front track bar needs to stay parallel to the drag link for proper steering geometry and only should be raised when in combination of a drag link flip (done typically at 3.5”+ of lift). Many bolt on lift companies will give you an adjustable front track bar to re-center your axle and a raised rear axle side bracket that raises the track bar mount by the same amount as the lift which will center the axle with the factory track bar. Some of the manufacturers that make lower end kits will address the track bar issue by including a frame side lowering bracket as well as a drop pitman arm. While this will correct the steering geometry, it will lower the roll center of the Jeep making it less stable in cornering on road and more tippy in off camber situations. The drop pitman arm will also increase the stress load on the steering box and can lead to bent sector shafts as well as leaking seals on the steering box.
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I was shocked at how much the rear tub and frame section weighed. 2"x.120 DOM weigh 2.5#s per foot. How many sticks did you use on that cage? Spare? Your shocks should be 300#'s+, heavier power train?, wheels and axles should come in close to a ton. Stock sport soft top is 4600#'s Coming in total under 6K is a pipe dream. I was 5530#'s on my 2 door with 40's before I cut the rear section off. It had doors on it but no roof or rear seats.
Kevin will get the last laugh on us all when he sets the new trend by mountin' his 4-ton toy on the tracks he talked 'bout. AND then ain't gonna have no worries 'bout the full hydro steerin'.

Mite take awhile to get to San Diego tho. :grin2:
Man I hope you guys are wrong. I fear you're not though.
Just squirt some hydrogen into all that tube and you're golden.
Have you seen Jeep's lower 40 build from years back? If you want to run 38s with no lift and want any sort of usable up travel, its going to require a bit more than a comp cut...
It's not up travel I am too concerned about. It's down travel. I'm more into overlanding/dirt trails. I rarely do rocks like most of you guys do.
I hope you have some wide axles. J.dub
haha, yes sir. That and negative offset.
Just squirt some hydrogen into all that tube and you're golden.
This man is not wrong.
I wonder if someone herecan give me some clarification. I'm about to redo the lift in my JKU. I am removing what's left of an Rk 2.5" Max travel lift, and replacing it with a 3 inch Teraflex lift with the Alpine adjustable arms. I have flat fenders, and was running 35, and I am going to 37s. I have already re geared, done C-gussets on the front and Chromo shafts in the rear. I am also planning to put in Synergy sector shaft brace. What other the things might I need to look at as far as clearance goes? I know this is probably been covered on this form before, but the search function on this page sucks.
edit - pinch seam is already dealt with.
I tried it with 4.5" backspace. Had to get Taran to get some 3.5" soft 8's. Then the rubber is 1" outside Bushwacker wide flatties. Whistler PoPo gonna be looking for you. No rubbing but the turning radius is in the crew cab long box range.
I tried it with 4.5" backspace. Had to get Taran to get some 3.5" soft 8's. Then the rubber is 1" outside Bushwacker wide flatties. Whistler PoPo gonna be looking for you. No rubbing but the turning radius is in the crew cab long box range.
Lol. Fortunately I live and work in Pemberton now. The Jeep is a toy now and just used for adventuring as I walk to work. I am hoping to keep my poke to a minimum. If I have to I'll add some garden edging or something like that to my Fender Flares. Might look like shit but it'llkeep the popo off my back. I might just try and use the rims I have for now and see how that works out, they have 41/4" BS, although I'm not sure what what they are.
That works for most
Hello thank you for the info Thedirtman .. I have a question about leveling kits to get rid of the factory rake .. I don’t understand why a 2 inch lift needs a new driveshaft or spacers for the exhaust on a Jku 2012 But a leveling kit which adds 2 inches to the coils in the front doesn’t need the same ..?? Any thoughts
I ran no lift with 35s, then ran no lift with 37s trimmed. Then 2.5”, then 3”. Worked fine on the street and gravel each time until I beach whaled my loaded 4 door all the way through the rubicon each version and made a 17 gallon gas tank out of a 21 over the course of 5 years.
It works fine unless you use it.
37s on a 4” is my sweet spot.

Edit: Not that anyone reads this shit.
I ran no lift with 35s, then ran no lift with 37s trimmed. Then 2.5”, then 3”. Worked fine on the street and gravel each time until I beach whaled my loaded 4 door all the way through the rubicon each version and made a 17 gallon gas tank out of a 21 over the course of 5 years.
It works fine unless you use it.
37s on a 4” is my sweet spot.

Edit: Not that anyone reads this shit.
I read it. Not sure I understood what you were saying :LOL:🍺
I read it. Not sure I understood what you were saying :LOL:🍺
He said he did not know how top pick lines and beat the crap out of the bottom of his heavy ass JKU.
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Correct on all fronts.
Heading up on Friday, I’ll make sure to look for all the low spots and load extra ballast.
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Makes sense ,we recently had a big event in logandale . I was trying to get this guy in a JLU on tons and 40s threw a big v notch that's shaped like a z . He had a front and rear 3link . It traked like crap! I had gotten half a dozen rigs through with no problem. But the 3link sucked balls.
(So did the driver )but still the rear just didn't follow well with full flex.

Sent from my SM-N950U using Tapatalk
He spent a lot of money to learn that lesson
Maybe this place is becoming a quagmire. While your answer is true, it is also infused with a get ****** attitude. You're sinking into my territory. What's next, I give someone positive, accurate advice on lifts?
Never!
This threat still lives after 12 years! LOL
After all this time people are still talking about Jeep weight, aerodynamics, fuel mileage etc lol…..8 years out of the community and glad nothing has changed! LOL
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You see it posted almost everyday “new jeep owner, what lift?” and we go thru the motions of what are you going to do with it and what tire size. You also get endless posts of “I am running * lift and it is better then stock” along with a poser shot. I still to this day do not understand how someone can see the suspension on a rig from 25 feet away in a photo. Those two important questions to consider when doing a lift, tire size and what you plan to do with it are the keys to setting up your suspension. I am keeping these thoughts mainly on the bolt on kits for the JK.

Most of the op’s have the misconception that somehow a bolt on lift will give them more articulation or “flex” and that a lift will make the Jeep more capable off road. Most will not and some will even make them less capable in some areas when compared to the factory suspension. Reduced wheel base, coil unloading, and low roll center are just some of the things that can happen with an incomplete bolt on kit that will be detrimental to off road performance. Play around with a 4 link calculator if you want to see how much your lift is messing with the actual geometry of your Jeep. The higher you go the worse it gets too.

While a 4” lift will increase the amount of up travel you have if you don’t run a longer shock you will loose 4” of down travel for a net increase in flex of zero. Add a 2” bump stop to the above example and you just lost 2” of flex vs the factory suspension set up. I think most people have this misconception of increased flex due to the fact they usually add larger tires when they lift and that is where they are seeing the improvement off road.

Many manufactures will use names with the word flex in them to describe their arms, lift kits, or joints. These are just marketing terms and do not flex any more then another bolt on kit from other manufacturers. The “upgradeable lift” is another myth made up from the marketing team. Any lift out there is upgradeable, there is nothing special about one that advertises it as one. The term "mid arm" is also a term that is made up by a marketing team, in reality it is the same basic length as the factory arm. They use this term in comparison to the tj control arms that were really short.

I believe that a lift is needed to gain clearance for increased tire size. It can also be used to gain some belly clearance for break over angle (mainly on the 4 door) and for better approach and declination angles, although I would argue that tires should be used for these issues instead of just lifting. The bigger your tires the more total ground clearance you will have as well as improving your break over, approach, and declination angles. I understand that other factors will come into play with large tires, mainly gears, wheel bs, and fuel economy.

If you were to compare two Jeeps, one set up with a 4" short arm kit on 33" tires and one with a 2" lift and 37" tires with trimmed fenders the one on 37's, if properly geared, would run circles around the higher lifted Jeep. It would climb better, clear bigger rocks, be more stable in off camber situations, and would handle better on road due to the lower center of gravity. Both Jeeps would be the same height overall.

For me the thoughts on lifts would be to start with trimmed or flat fenders for 33’s add a 2” lift for 35’s a 3” lift for 37’s 4” for 40’s
Expect some trimming of pinch seams as your tires get larger in size.

Wheel bs should be included in the discussion as well to maintain full steering. Wheel back spacing for the previous lift recommendations on factory width axles.

Net max back spacing:
5.5” for a 33x12.5
4.5” for 35x12.5
3.5” for 37x12.5
1.75” for a 40x13.5



The Parts:

Coils:

Coils are what gives your Jeep it’s ride height, in its most simple form a lift is just longer coils or a spacer placed on top of the coils. The benefit of a longer coil vs a spacer lift is that it will have a bit more travel built into it so you can droop a bit more and run a longer travel shock. A dual rate coil is made with a light coil rate section that will compress at ride height and allow for an even longer throw at full extension allowing for the potential of increased articulation. A coil that minimizes lift and maximizes unloaded length will give you the most benefit for increasing flex and off road performance.
One drawback from a coil that is really long is unloading that occurs on a steep climb or decline when the coils push the jeep away from the axles and give you the possibility of flopping onto the roof. Limit straps and suck down winches can help with that problem. ORI struts have a built in feature that eliminate this problem as well.

Shocks:

Shocks control the compression and rebound of the coils, quality of the ride, and the upper and lower limit to a suspension. To increase articulation, total travel is what you are looking for. Typically for 33”-35” tires you will be looking at a 10” travel shock. With 37”-40” a 12” travel shock will do. These are for bolt on kits, if you want to get adventurous and are willing to cut and weld 14”-16” are doable with considerable effort.

When running a longer travel shock you will have to take into account the rotation of the axle when one wheel is drooped and one is stuffed. The stuffed wheel will travel farther into the wheel well and you will experience more axle shift where a driveshaft may make contact with the fuel tank or oil pan.



Bump Stops:

Bump stops are there to keep your tires and other suspension components from rubbing on fenders and the frame. They are also used to keep shocks from totally compressing which can potentially damage them. When adding larger tires or doing a drag link flip you will need to add bump stops to keep things from rubbing. You can also trim fenders or notch the frame to gain extra up travel. Remember when adding bump stops you are limiting your up travel and are reducing your flex. Trimming fenders or running flat fenders is a good way to increase flex if tire rubbing the fenders is your limiting factor vs running longer bump stops.

Limit Straps:

Limit straps limit your down travel and can reduce your flex. However If set up properly the limit strap will prevent your shocks from totally extending, potentially damaging them, and can actually allow you to increase flex by overcoming the limitations of other components such as the drive shafts. By placing a limit strap at the differential you can limit the angle of the u joints or keep a driveshaft from making contact with the exhaust cross pipe while still allowing more droop at the wheels so the axle can rotate over obstacles. I have not seen a single lift that offers limiting straps, though they should be in every kit over 3” at least at the front driveshaft.

Sway bars and links:

While most of you disconnect your sway bars when off roading, (I don’t run them at all but my set up is far from a bolt on) should you run off road with them connected you run the risk of flipping your sway bar forward if your sway bar links are too short. This will lock up your steering and will likely bend stuff. They should be sized so they are +- 5 degrees from level. I would error at the +5 if it were me as I have flipped mine a couple of times when I over extended the front end.

Disconnecting the links will give you more potential travel in your suspension but will also make it less stable in off camber situations. After market sway bars like the TeraFlex duel rate or the Currie anti-rock will give you extra stability while having a softer twist rate for articulation.

Track Bars:

Track bars keep your axles centered on the Jeep. As you articulate your suspension the axle will shift from side to side. When you droop the front the axle moves to the driver side. The opposite happens on the rear. As you lift the track bar becomes more angled and due to that angle will shift more then a stock or level track bar. The track bar also determines your roll center. This is a line drawn thru the center of the front and rear track bars to determine how the vehicle will roll on its suspension from side to side. Think of a top heavy feeling from a low roll center. Raising the rear axle side track bar bracket will increase the roll center and make the Jeep feel more stable during off camber situations and on road cornering. The front track bar needs to stay parallel to the drag link for proper steering geometry and only should be raised when in combination of a drag link flip (done typically at 3.5”+ of lift). Many bolt on lift companies will give you an adjustable front track bar to re-center your axle and a raised rear axle side bracket that raises the track bar mount by the same amount as the lift which will center the axle with the factory track bar. Some of the manufacturers that make lower end kits will address the track bar issue by including a frame side lowering bracket as well as a drop pitman arm. While this will correct the steering geometry, it will lower the roll center of the Jeep making it less stable in cornering on road and more tippy in off camber situations. The drop pitman arm will also increase the stress load on the steering box and can lead to bent sector shafts as well as leaking seals on the steering box.
Dirtman, glad to see you are still around and greatwrite up….I am BACK! Lol
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Picking up my Jeep tomorrow. Had the Clayton 3 link front long arm kit installed, along with the TeraFlex HD steering system, ball joints and their knuckles. I'll post some pictures. Not sure what to do with the rear yet. It's sitting on 3.5 coils from AEV at the moment. Front drive shaft is now a Tom Woods piece with the 1350 u-joints. This thread is excellent by the way.
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