Suspension Upgrade Questions

[prodriquez]

In all seriousness, most shops just want to sell you parts based on your budget rather than discover your needs, goals, and performance expectations… which is an extremely expensive and often frustrating journey.

To me, it sounds like you have a good build but you’re carrying too much weight for your springs and your shocks simply cannot compensate for the difference. I also suspect that a 2.5” lift is not enough lift for the type of wheeling you want to do and the lines that you want to take.

My advice is to drive some other jeeps and get a feel for how they handle/perform while on-road and off-road.Here are some 392 suspension lift height generalizations to consider:

• 2.5” lifts will be optimized for OEM weight and on-road handling characteristics. They are not optimized for off-road use but they will accommodate a 37” tire. They are great for occasional off-road use without sacrificing (much) on-road performance.
• 3.5” lifts strike a balance between on-road and off-road performance. This lift offers higher clearance and can accommodate up to a 39” tire and is ideal for the weekend wheeler that wants to do moderate to severe trails (6 to 9 rated).
• 40’s and extreme lifts are loaded with trade offs… so I will simply say that nothing on the Jeep was designed to handle a 40. Do your own homework and I’ll encourage you to check out some of my previous posts on this topic.

If 2.5” of lift works for you… I would replace the springs, with a heavier duty spring, and I would hold off on replacing the shocks until you have an opportunity to evaluate their true performance. Alternatively, buy some King Coilovers and go completely custom . I’ll recommend Filthy Motorsports out of Boulder, Co. if you want to go the custom route. I have no affiliation… just respect

 

[3TV]

Thanks everyone I appreciate the guidance.

I went to a Cat scale at a local Loves truck stop on the way home from work tonight. And with a full tank of gas and the usual recovery gear and survival gear I carry at all times, plus two persons in the Jeep, here is what I found out:

Gross weight: 6,510 lbs
Steer Axle: 3,300 lbs
Rear Axle: 3,210 lbs

I was surprised that the front to rear weight bias on my 392 was so even.

I remember reading somewhere that a stock 392 XR weighs 5,320 lbs, or something like that.

 

[3TV]

So, here is what I would like to do.

Metalcloak 3.5" springs.
King shocks. Front 17" collapsed length and 28" extended length
Rear 18" collapsed length and 30" extended length
New front driveshaft.
38" Nitto Trail Grapplers
Teraflex Nomad Split Spoke wheels 17x8.5 -12 offset (4.25" backspacing).
Next Venture fenders and inner liners.

But is that what I should do?

Do the Metalcloak 3.5" springs have the same spring rate as my current Metalcloak 2.5" springs? Do I need springs with a higher weight rating? Are the Teraflex Outback springs the same rate as the regular 392 specific springs, or different? If I go with 3.5" lift Teraflex Outback springs, or another brand of springs, will they have the same amount of droop as the Metalcloaks, or will I need shorter shocks to prevent the springs from falling out? Jeep Guru, you guys sell and use all of this stuff, you have access to company reps. Do the companies have a weight cutoff where they recommend going to a higher capacity spring?

 

[prodriquez]

You’re definitely fat (@ 6500 lbs.) and should be running some HD springs. I would also recommend some more uptravel (lift) so you don’t bottom out as much . Ideally, MC has something that works with your existing leveling spacer.

 

[Rusty762]

Man, if they only made some kind of long travel shock that somehow incorporated 2-different spring rates, had an adjustable lift height, adjustable valving, rebuildable, and was race proven!

#kingcoilovers

If, no when I have the money that will be the route I go. Had to sell my LJ, but there is just nothing better than King Coilovers...