Lift "Math" 4.5" = 6.5"?

NOTNSUV

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4.5" RE springs & short arms.

Rear coil relo. With what I've read the rear relo adds 1.5 - 2" and is a small improvement in bump stop alignment and coil arch. They appear to be a bolt on unit and the OEM perches are still in place. I'll post a picture if the rain slows down for a dash to the shop.

ACOS up front, adding 2", 1.25" height at minimum adjustment + the 3/4" actual adjustment
I assume ACOS were added to compensate for the added rear height with the rear relo brackets.

By my math, I'm looking at 6.5" net lift.
Add 1.25" BL. It's just too much, eh? Also, height to top of sliders is 31", quite a leap for me and a real challenge for my 5'-nothin' wife.
All I want is to run and clear 35s (already on it)
I think the Bilstein 5100 are for a 4" lift so likely too short for this application.

Options as I see it:

1) leave all this in place and replace coils with 3" Rock Jock Springs, losing 1.5" and getting me 'down' to approximately 5", still probably more than needed.
2) remove ACOS and relo and live with coil arch and possible bumpstop misalignment but lose maybe 2".


Will this lower spring require a pinion adjustment and/or alignment? Future goal is full Rock Jock kit with double adj. track bars but figure I can get away with the RE CA until then. Wanting to do the suspension before the re-gear/axles.

I'm wide open to suggestions, school me please.

Thanks.
 
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4.5" RE springs & short arms.

Rear coil relo. With what I've read the rear relo adds 1.5 - 2" and is a small improvement in bump stop alignment and coil arch. They appear to be a bolt on unit and the OEM perches are still in place. I'll post a picture if the rain slows down for a dash to the shop.

ACOS up front, adding 2", 1.25" height at minimum adjustment + the 3/4" actual adjustment
I assume ACOS were added to compensate for the added rear height with the rear relo brackets.

By my math, I'm looking at 6.5" net lift.
Add 1.25" BL. It's just too much, eh? Also, height to top of sliders is 31", quite a leap for me and a real challenge for my 5'-nothin' wife.
All I want is to run and clear 35s (already on it)
I think the Bilstein 5100 are for a 4" lift so likely too short for this application.

Options as I see it:

1) leave all this in place and replace coils with 3" Rock Jock Springs, losing 1.5" and getting me 'down' to approximately 5", still probably more than needed.
2) remove ACOS and relo and live with coil arch and possible bumpstop misalignment but lose maybe 2".


Will this lower spring require a pinion adjustment and/or alignment? Future goal is full Rock Jock kit with double adj. track bars but figure I can get away with the RE CA until then. Wanting to do the suspension before the re-gear/axles.

I'm wide open to suggestions, school me please.

Thanks.
FWIW. Tire to bottom of flare.
Front 7.25"
Rear 9.25" PXL_20211025_163112219.jpgPXL_20211025_162822873.jpg
 
rather than trying to add and subtract all the incremental changes, it's much easier to just measure the spring height plus any non-factory spacers. The front spring was 12" at ride height so anything you have above that is lift.

You can't really do that in the rear since your spring perches aren't stock anymore, but if you don't have an excessive amount of rake or reverse rake then it should be close enough to call it the same.

I don't really see people going for more than 4" of suspension lift. There are other ways to get tire clearance, and things start going downhill above 4". Driveline geometry goes to crap, suspension geometry gets weird at both ends, it's just ugly.

4" - 33s
4" plus 1.25" body - 35s
4" plus 1.25 body plus highlines and wider axles - 37s.
 
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rather than trying to add and subtract all the incremental changes, it's much easier to just measure the spring height plus any non-factory spacers. The front spring was 12" at ride height so anything you have above that is lift.

You can't really do that in the rear since your spring perches aren't stock anymore, but if you don't have an excessive amount of rake or reverse rake then it should be close enough to call it the same.

I don't really see people going for more than 4" of suspension lift. There are other ways to get tire clearance, and things start going downhill above 4". Driveline geometry goes to crap, suspension geometry gets weird at both ends, it's just ugly.

4" - 33s
4" plus 1.25" body - 35s
4" plus 1.25 body plus highlines and wider axles - 37
At ride height:

Front spring only = 17"
Including ACOS = 20" to bottom of upper perch (no OEM pad or such). ACOS is set at 3/4".
Nth Degree BL 1.25"

Front to rear is close to level with no discernible rake. Receipt from installing shop says RE 4.5" lift.

Would you say I'm in this zone: "things start going downhill above 4". Driveline geometry goes to crap, suspension geometry gets weird at both ends, it's just ugly."?
Hence my concerns and impetus to correct this.
 
At ride height:

Front spring only = 17"
Including ACOS = 20" to bottom of upper perch (no OEM pad or such). ACOS is set at 3/4".
Nth Degree BL 1.25"

Front to rear is close to level with no discernible rake. Receipt from installing shop says RE 4.5" lift.

Would you say I'm in this zone: "things start going downhill above 4". Driveline geometry goes to crap, suspension geometry gets weird at both ends, it's just ugly."?
Hence my concerns and impetus to correct this.

probably. That's a ton of lift. If the shocks are properly selected (with at minimum 4" downtravel from ride height), the driveshaft is probably going to bind at droop unless there's a center limit strap. The bilsteins may just not be long enough to let this happen but it'll be something to look at if you get longer shocks.

Rear suspension probably has a ton of antisquat. Does it hop when trying to climb an obstacle?

Front LCA's probably at a pretty steep angle at ride height...and again, at full droop with decent downtravel there's a danger of an obstacle folding the axle backward under the rig and ruining your day.

The suspension stuff may not apply if you have mid or long arms.
 
probably. That's a ton of lift. If the shocks are properly selected (with at minimum 4" downtravel from ride height), the driveshaft is probably going to bind at droop unless there's a center limit strap. The bilsteins may just not be long enough to let this happen but it'll be something to look at if you get longer shocks.
Bilsteins seem to be too short for this setup from a phone conversation with Rock Jock and some measurements.
Rear suspension probably has a ton of antisquat. Does it hop when trying to climb an obstacle?
Haven't had it off the pavement. Just got it last month.
Front LCA's probably at a pretty steep angle at ride height...and again, at full droop with decent downtravel there's a danger of an obstacle folding the axle backward under the rig and ruining your day.
I haven't measured the CA angle but yes, it's steep. Put CA drop brackets on front of my XJ to minimize this same thing. Made a world of ride difference. I'm not suggesting I'd do that with these short arms. I want to correct this the right way. I'm hopeful 3" springs will be a good start.
The suspension stuff may not apply if you have mid or long arms.
 
I'd remove the ACOS and rear relocation kit. On an LJ, assuming you're running a SYE, you will get minimal spring bow. At that point, your 4.5" RE springs should be about damn near perfect. You can use the 1/2" or 3/4" spring spacers as needed to level your suspension out depending on how you have it set up (hard/soft top, rear cargo, etc).
 
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I'd remove the ACOS and rear relocation kit. On an LJ, assuming you're running a SYE, you will get minimal spring bow. At that point, your 4.5" RE springs should be about damn near perfect. You can use the 1/2" or 3/4" spring spacers as needed to level your suspension out depending on how you have it set up (hard/soft top, rear cargo, etc).
Fortunately, unlike the XJ the TJ/LJ does not get the spring mount cut out with ACOS installation, just unbolted, so I'm not 'married' to it.
I'm waiting on new OEM front spring hardware to give that a try, isolator spring (7), jounce bumper (8), and bolt (9). Had to get the jounce bumper cup online since Mopar discontinued. Am I missing something?

https://www.moparpartsgiant.com/pag...trol_arms_and_track_bar&diagram=&partNumbers=
Your suggestion is definitely the least expensive of the options. Gonna have to dig in and make sure the rear relo isn't welded somewhere. Weird it would have only one U bolt holding it on

I don't know why the OP or his shop in AZ decided that combo was the way to go.

Oh ya, spare tire on back, hardtop (except Summer, I hope) and carry recovery gear, tools, fuel, water.. the whole shaboom so considerable weight some of the time. Do most of this out of the XJ so we'll see how it goes.
 
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Fortunately, unlike the XJ the TJ/LJ does not get the spring mount cut out with ACOS installation, just unbolted, so I'm not 'married' to it.
I'm waiting on new OEM front spring hardware to give that a try, isolator spring (7), jounce bumper (8), and bolt (9). Had to get the jounce bumper cup online since Mopar discontinued. Am I missing something?

Your suggestion is definitely the least expensive of the options. Gonna have to dig in and make sure the rear relo isn't welded somewhere. Weird it would have only one U bolt holding it on

I don't know why the OP or his shop in AZ decided that combo was the way to go.

Oh ya, spare tire on back, hardtop (except Summer, I hope) and carry recovery gear, tools, fuel, water.. the whole shaboom so considerable weight some of the time. Do most of this out of the XJ so we'll see how it goes.
Should be what you need in the front to get you going with a stock-style setup...

No idea on the rear, they had so many variants over the years I've stopped trying to track them all.

For weight, I didn't need any spacers in the front or rear and have a fairly leveled stance. On my TJ, I had to run 3/4" front spacers to get the stance I preferred. Even when loaded up, I don't notice too much squat (thankfully!)...
 
Not sure what you're seeing. Swaybar tilted up? Never had one to compare to so.. ??

Exactly. If the bar goes straight with the link at full droop, it can flop the other way when it comes back off of droop and really screw things up. The angle they're at suggests that it wouldn't take much droop to reach that point.
 
Exactly. If the bar goes straight with the link at full droop, it can flop the other way when it comes back off of droop and really screw things up. The angle they're at suggests that it wouldn't take much droop to reach that point.
Should it be more parallel to the ground?
And is will move that way when I reduce the lift height, correct?