Spring rates for a heavy Jeep?

[3TV]

My '22 JLUR 392 XR is pretty weighed down with aftermarket steel skid plates, rock sliders, bumpers, and a winch. But a good part of the weight is also recovery gear, tools, and survival gear. I'm a bit of a survivalist, and my Jeep stays equipped with a lot of gear.

I have a Metalcloak 2.5" Gamechanger lift that gave my loaded down 392 XR 1" of lift. I would like another 1.5" to 2" of lift to help prevent constantly dragging the skid plates.

I weighed my Jeep on a local Loves truck stop CAT scale.

Gross Weight: 6510 lbs
Steering Axle: 3300 lbs
Drive Axle: 3210 lbs

This was with a full tank of gas, the usual daily supplies that are always in the Jeep, and two peoples on board. Weight of both said peoples estimated to be <350 lbs (she won't tell me how much she weighs).

With that in mind, what do people think regarding appropriate spring rates? Do I need to change to a higher spring rate, such as the Teraflex Outback springs, or just change from my Metalcloak 2.5" springs to 3.5" springs. I have Accutuned Fox 2.5 DSC shocks that I have dialed in fairly well. I am running the stock XR bumpstop length with no tire rub with 37" tires. I am not having a problem with the suspension bottoming out too much. The shock settings really take the bigger hits nicely.

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[GATORB8]

You'll need to look at free length with a single rate like the TF.

If you currently like the ride and handling, I think I'd stay MC, either the 3.5, or maybe the 4.5 if it get's you closer to target ride height.

Another option would be triple rate like the RKs where you have a third heavy rate under squat.

 

[3TV]

Thanks. I'll try and check out both of those.

 

[Nokones]

You need to contact Clayton for the springs and Accutune Off-Road for the shock package for those kinds of weights.

 

[BDinTX]

Suggest you keep an eye on your rear spring perches. I’m only a YouTube engineer but I don’t think the design is very good since the perch is acting like a lever against the welds to the frame and crossmember.

My welds were crap from the factory but I don’t know that all of the folks that had problems can say the same.
https://www.jlwranglerforums.com/forum/threads/2018-jl-upper-rear-spring-perch-failure.96988/

 

[3TV]

You need to contact Clayton for the springs and Accutune Off-Road for the shock package for those kinds of weights.

I've been doing some research ...

Spring free length for Metalcloak 3.5" lift springs are 22" front and 19.5" rear
Clayton 3.5" lift springs are 19.3" front and 18.5" rear.
Teraflex does not publish free length of their Outback 3.5" lift springs. I will call.

Shock lengths for Metalcloak Black 3.5" lift: Front 17.2" - 28.5"; Rear 18.2" - 30.5"
King Accutune for 3" to 5" lift: Front 18.1" - 28.8"; Rear 19.2" - 30"

I'm changing to 40" tires at the same time I am changing suspension, and I expect a 1" bump stop extension will be needed. So, the longer compressed length of the King shocks should be ok.

I am not sure the 3" shorter free length of the Clayton front coils, and 1" shorter free length of their rear coils will work well for maximum flex though

 

[JEEP4U]

I have the same issue, I'm on 40's.

Since you have only a 2.5lift. I would go with Rock Krawler 3.5" for a JLU 4XE and get their thick rear spring correction pad.........

or if your spring rate seems fine (no constant bottoming out) you could use your old springs and install JKS Manufacturing rear adjustable coil spacer kit....... gives you 1.75"-2" extra lift min.

 

[3TV]

I have the same issue, I'm on 40's.

Since you have only a 2.5lift. I would go with Rock Krawler 3.5" for a JLU 4XE and get their thick rear spring correction pad.........

or if your spring rate seems fine (no constant bottoming out) you could use your old springs and install JKS Manufacturing rear adjustable coil spacer kit....... gives you 1.75"-2" extra lift min.

Bingo, we have a winner! I just checked out the ACOS coil spacers, and they are exactly what I need. Thanks, JEEP4U.

I had been dreading changing springs and having to readjust for the JL lean. Right now, I have a 3/4" spacer in the right rear and a 1/2" spacer in the right front in order to have a level Jeep with my Metalcloak 2.5" lift. But who knows what new springs are going to do for the lean, and if I will need the same spacers or different spacers, or none. The ACOS gives me the additional lift I want, makes it easy to adjust rake, and makes it easy to eliminate any lean.

I am not constantly bottoming out, even with the weight of my Jeep. With proper dialing in of my current shocks it rarely bottoms out, it just rides too low and drags its belly on tougher trails. Too bad I need longer shocks after adding more lift. But that's ok, my wife's JT may inherit a set of Accutuned Fox 2.5 DSC shocks. Her JT is already going to inherit my 37" Cooper STT Pro tires.

So, this whole thing has become rather simple. ACOS coil spring spacers at both ends to dial in height, a new set of Accutuned King shocks that are tuned for my Jeeps weight, and are the proper length, and a new front driveshaft. Along with the Next Venture fender flares and inner fender liners that are in the garage waiting to be installed, I should be good to go.

Stage 1 served its purpose for the last 18,000 miles. Stage II is now ironed out. Stage III will be UD 60s, sooner or later.

 

[JEEP4U]

Bingo, we have a winner! I just checked out the ACOS coil spacers, and they are exactly what I need. Thanks, JEEP4U.

I had been dreading changing springs and having to readjust for the JL lean. Right now, I have a 3/4" spacer in the right rear and a 1/2" spacer in the right front in order to have a level Jeep with my Metalcloak 2.5" lift. But who knows what new springs are going to do for the lean, and if I will need the same spacers or different spacers, or none. The ACOS gives me the additional lift I want, makes it easy to adjust rake, and makes it easy to eliminate any lean.

I am not constantly bottoming out, even with the weight of my Jeep. With proper dialing in of my current shocks it rarely bottoms out, it just rides too low and drags its belly on tougher trails. Too bad I need longer shocks after adding more lift. But that's ok, my wife's JT may inherit a set of Accutuned Fox 2.5 DSC shocks. Her JT is already going to inherit my 37" Cooper STT Pro tires.

So, this whole thing has become rather simple. ACOS coil spring spacers at both ends to dial in height, a new set of Accutuned King shocks that are tuned for my Jeeps weight, and are the proper length, and a new front driveshaft. Along with the Next Venture fender flares and inner fender liners that are in the garage waiting to be installed, I should be good to go.

Stage 1 served its purpose for the last 18,000 miles. Stage II is now ironed out. Stage III will be UD 60s, sooner or later.

I have been using the JKS ACOS adjustable coil spring spacers for a couple season now.........

 

[3TV]

Well, stage 2 is ordered.

40" Toyo MTs arrive tomorrow
Accutune King shocks arrive in 8 days
ACOS arrive ?

The big wait now is scheduling powder coat for the Next Venture fender flares

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