Options with metric ton springs

[jakeWI]

Sorry if this is out there, I did try and search.

 

But I have a set (well two sets) of Metric Ton springs. I know they usually give you a gain of 3" from stock springs. What are my best options if I want to go say 6" and keep the MT springs? Because if I remember right, do SOA with those would give me roughly 7" right?

 

I was originally going to keep it stock height or roughly 3" but I am getting an itch again and going from my built XJ to stock is getting hard...

[Eagle]

But I have a set (well two sets) of Metric Ton springs. I know they usually give you a gain of 3" from stock springs. What are my best options if I want to go say 6" and keep the MT springs? Because if I remember right, do SOA with those would give me roughly 7" right?

No, they don't. Metric Ton springs should give the same ride height as stock springs, just with more load capacity. If the springs you have generate 3 inches of lift, they are not Metric Ton springs (regardless of what their maker or vendor calls them).

 

Have you installed either set yet? Do you know they produce 3 inches of lift, or are you assuming that because of something you read or heard?

[skidoo_j]

It's possible for people to get almost 6" of lift with a SOA conversion with non-metric tons springs. Going SOA is similar to a block lift.

 

If you're trying to figure out how much lift you will receive from an soa measure and ad, the diameter of your axle tube, the thickness of your oem perch, the height of the new perch (this is where people can gain additional lift) and the thickness of the spring pack.

 

That is where the lift in the rear comes from when doing an SOA. When a non altered truck has a metric ton pack the ride height is the same as they are Spring Under the axle, so the aditional leafs in the metric pack have no influence on the main leafs position only carrying capacity. When SOA converted the additional leaf and thickness of leaf will increase the lift vs a non-metric ton spring set.

 

hellcreek springs does use one of the metric ton (4+1) design to manufacture 3" lifts while maintaining SUA. I however do not think they still metric ton rated.

 

IIRC hellcreek's official Metric ton springs are the 3+2 design and are sold as stock height. When i personally was looking for new leafs, HELLCREEK was the only manufacture that I found that was using steel that was OEM or better in grade, and were the only ones using steel from US manufactures. There is a reason they're 230 a side vs 230 for a set. Anyone on here that has a hellcreek lift or Metric ton springs loves them.

[skidoo_j]

Sorry if this is out there, I did try and search.

 

But I have a set (well two sets) of Metric Ton springs. I know they usually give you a gain of 3" from stock springs. What are my best options if I want to go say 6" and keep the MT springs? Because if I remember right, do SOA with those would give me roughly 7" right?

 

I was originally going to keep it stock height or roughly 3" but I am getting an itch again and going from my built XJ to stock is getting hard...

 

 

To tell if these are actual factory metric tons, assuming they are not installed you can measure their free arch. this is the distance from a line running from eye o eye to the spring pin. stock springs both non-metric ton and metric ton are around 9" plus minus 1/2" or so.

 

Here are factory specs on metric ton

Metric Ton 3+2 Spring Specs

Metric Ton 4+1 Spring Specs

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In another post somewhere someone also posted the specs of all the known factory leafs by part number.

[skidoo_j]

here's some info from previous threads:

 

I just so happened to recently replace my factory 4x4 leafs with 3+2 MT springs from Hellcreek. I also took a few pictures...

 

Rear ride height before swap: 10" to the top of the rim

 

Stock vs new MT. Exact same eye-to-eye and height dimensions.

 

MT installed ride height: 11" to the top of the rim

 

Net result: 1" of lift in the rear. The leaf itself isn't giving more lift by dimensional design, but since the spring rate is higher the bed doesn't compress the spring as much, giving an unloaded lift of 1".

 

 

 

Here is the run down:

 

980 lb. capacity = 7.62" free arch, OEM part #89-52-002-312, 3+1 configuration

1100 lb. capacity = 8.75" free arch, OEM part #89-52-001-240, 3+1 configuration

1160 lb. capacity = 9.25" free arch, OEM part #89-52-002-351, 3+1 configuration

1220 lb. capacity = 9.75" free arch, OEM part #89-52-001-824, 3=1 configuration

1280 lb. capacity = 10.25" free arch, OEM part #89-52-002-350, 3+1 configuration

1440 lb. capacity = 9.12" free arch, OEM part #89-52-001-825, 4+1 configuration

1700 lb. capacity = 9.50" free arch, OEM part #89-52-003-676, 3+2 configuration

 

 

The first 5 springs are identical except for the free arch. The 1440 lb. spring has the 1st two leaves made from .291 thick steel, the next two leaves made from .262 steel, and the thick two-stage leaf from .625 steel. The MT spring has the 1st leaf made from .291 steel, the next two made from .323 steel, the long two-stage leaf made from .590 steel, and the bottom two-stage leaf from .625 steel. The same main leaf fits all seven springs. In the spring industry, the term "Free Arch" stands for the arch of the spring measured perpendicularly from the top of the main leaf at the center bolt location to a line drawn through the centers of the eyes, while the spring is in its free state (unloaded and off the vehicle). It's an industry term. :smart:

 

-Tom

 

Oh and later in the thread they go over how free arch is not directly related to ride height because of the spring rates and the varying thickness of steel. I took it only to measure when i took a set off at the junk yard to see how bad they were.

[jakeWI]

hmm interesting. Thanks guys.

 

Yeah I was told they give roughly 3" of lift. I am fairly new to MJ's so I had no real idea. I currently have two sets of MT springs (installed on two separate jeeps) and one jeeps rear end is roughly 2-3" higher. You can tell that they have been replaced with a new spring and I was told they are a metric ton variety.

 

And since I was told they would be roughly 3" of lift, I didn't want to do spring over and have way to much lift then needed. I liked 6" on my XJ and wouldn't mind doing it again on the MJ.

[HOrnbrod]

Theoretically, you can get up to 3" of lift by installing new MT springs. I got about 2-1/2" (measured from the ground to the the flare bottom before and after with the same tires), and these were regulation 3+2 MT springs with 9-1/2" of free arch. But the stock original non-MT springs I replaced were completely sagged out and gone. So I did get 2-1/2" of lift over what I had originally.

 

As stated above, using new MT springs and new non-MT springs the rear end will remain at the same height on an unloaded NJ. Going to SOA, you can do your rough calculations to try and predict lift, but SOA conversions always seem to give more lift than expected.