OME spring comparison

[dapipp]

So I am starting the build process on a LJ with a hardtop, Nth Degree Mobility tummy tuck and Poison Spyder rockers.. I have some thoughts on what suspension I want to use but have some questions about the different OME springs.

The LJ has both a heavy front and rear end. The front bumper weights about 85 lb. and the winch weighs about 95 lb. The rear bumper (swing out) weighs about 170 lb. plus the weight of the spare.

I intend to run 32" to 33" tires, nothing larger. I also have a .5" Rokmen body lift.

I am looking at OME 2" springs with Nth Degree Mobility Rear Spring Relocators TJ/LJ Wrangler (https://www.nthdegreemobility.com/rear_spring_relocators_tjlj_wrangler) and Nth Degree Mobility 2" Coil Spring Spacers XJ/ZJ/TJ/LJ (https://www.nthdegreemobility.com/2_inch_coil_spring_spacers_xjzjtjlj).

I figure that between the OME springs and the Nth Degree Mobility parts I should have enough room for 33" tires.

I am also leaning towards all JKS suspension arms and trackbars.

My problem is picking the correct OME springs.

For the rear there appears to be two options:

2949 - JEEP UNLIMITED REAR HEAVY CONSTANT LOAD (220 TO GVW)
2996 - JEEP UNLIMITED REAR COIL SPRING (CONSTANT 400LBS)

I have the same basic issue with the front:

2934 - ZJ 5.2L V8 FRONT HEAVY LOAD (90-180LBS) - recommended by friend
2933 - FRONT (6 CYL.) HEAVY LOAD (90-180LBS)

I have not found any good description of the springs or their differences. I did find a document that explains this info but it is Greek to me.

My other thought is to go with a complete Nth Degree Mobility solution but their smallest spring is 3" and with the relocator I feel it will put be up to 4" of lift. Not sure I want to be that high. Then again I may not be that high based on the weight of the jeep.

Nth Degree Mobility Jeep LJ 3.0" Frequency-Tuned Rear Coil Springs (https://www.nthdegreemobility.com/jeep_lj_30_frequency_tuned_rear_coil_springs)

Nth Degree Mobility Jeep TJ/LJ 3.0" Frequency-Tuned Front Coil Springs (https://www.nthdegreemobility.com/jeep_tjlj_30_frequency_tuned_front_coil_springs)

As a side note I am thinking of running 4.88 gearing.

Thoughts?

 

[ac_]

I have OME on my TJ, I started with Heavy/Heavy, and it gave me way too much height in the rear, but I don't have a back seat nor a hard top and my rear bumper/tire carrier is pretty light, and I am running 31's. I called ARB and showed them pictures. They told me to go lights in the back and that actually fixed my issue.

OME also comes with approximately 1/2 inch spacers so you can adjust front to rear, and they also told me that rarely do you put the OME in the first time, and it is perfect usually you make adjustments with the spacers. Of which I ended up doing to finally get it where I want it.
the spring rate between light and heavy are not that different. I mean I drove it around with the heavies a couple of weeks before I changed it to lights and it didn't really change the ride noticeably. It does definitely ride better than stock.

Sorry to say, I have no experience with 9th degree so you will have to decide that on your own.

My suggestion though is if you have a hard top, and you go OME, I would go heavy/heavy.

Just for clarity I ended up with Heavy fronts with spacers and light rears with no spacers and I am perfectly level from frame to ground within 1/4 inch. I just say this to clarrify where I finished most TJ/LJ's will be different. I read a lot where people are putting in 3/4 spacers up front, but mine didn't need that. Maybe If i would have stuck with the heavies in the rear.

Clear like mud?

 

[Jerry Bransford]

2" springs aren't enough for 33" tires, you need at least 3" with a 1" body lift recommended for 33x12.50 tires. For all that extra weight you're carrying you want the higher of the two spring rates which basically means how stiff the spring is and if it's meant for lighter or heavier loads.

For a smaller lift like 2" or 3" I"m not sure if I see enough benefit to those rear spring relocators to warrant their cost. I'm not even running them with my 4" springs though I can see the benefit with my 4" of lift. Personally I'd go with 3" springs with a higher spring rate plus a 1" body lift if you want to run 33" tires. A set of 1" taller motor mounts will help correct the excessive drivetrain angle (at the rear driveshaft u-joints) given by a 3" suspension lift and can eliminate the need for a big t-case skidplate drop or a SYE kit and CV driveshaft.

 

[ac_]

A set of 1" taller motor mounts will help correct the excessive drivetrain angle (at the rear driveshaft u-joints) given by a 3" suspension lift and can eliminate the need for a big t-case skidplate drop or a SYE kit and CV driveshaft.

I am curious about this statement. I see this a lot.
Here is my question. when I did my 2" lift I actually got more like 4 inches in the rear because I have no weight, to offset that I did a1 inch drop on the skid plate and the vibration did indeed go away other than a slight vibration taking off, but what happened instead is it was a real bitch going into 2nd because the stick crammed into the center console. So what I did to fix it was to put the light springs and remove the spacers in the rear and it dropped it back down 2"s and leveled me out so I removed the skid plate drop and the shifting went back to normal and still no vibrations.

That said: will the raised motor mount essentially do the same thing as the transfer case drop and cram the stick shift into the console in 2nd gear, and if so I would then definitely recommend the SYE over the dropped skid, or raised motor mount if you have a 5sp. Or perhaps remove the console altogether.

 

[bobthetj03]

@ac_ , I think it has a lot to do with the angle at which the entire drive train(engine, trany, TC) is sitting. With the motor mounts being the pivot point of the drive train, it is already sitting at a slight downward angle. Drop the TC and the angle drops even more which moves the relationship of the trany to the tub and thus moves the shifter rod back, binding the dust boot that is under the console when you shift back for 2nd gear. Reverse was affected on mine as well. That is why most recommend doing the body lift at the same time, thus restoring the relationship of the tub to the trany and TC linkage. By doing just a MML without also doing the BL, you are once again changing the relationship of the tub to the trany, shoving it closer to the tub and back again, which might also bind with the dust boot.

 

[ac_]

@ac_ , I think it has a lot to do with the angle at which the entire drive train(engine, trany, TC) is sitting. With the motor mounts being the pivot point of the drive train, it is already sitting at a slight downward angle. Drop the TC and the angle drops even more which moves the relationship of the trany to the tub and thus moves the shifter rod back, binding the dust boot that is under the console when you shift back for 2nd gear. Reverse was affected on mine as well. That is why most recommend doing the body lift at the same time, thus restoring the relationship of the tub to the trany and TC linkage. By doing just a MML without also doing the BL, you are once again changing the relationship of the tub to the trany, shoving it closer to the tub and back again, which might also bind with the dust boot.

So if that is the case, it seems that the SYE is the best solution especially with us with a manual.

 

[JMT]

So I am starting the build process on a LJ with a hardtop, Nth Degree Mobility tummy tuck and Poison Spyder rockers.. I have some thoughts on what suspension I want to use but have some questions about the different OME springs.

The LJ has both a heavy front and rear end. The front bumper weights about 85 lb. and the winch weighs about 95 lb. The rear bumper (swing out) weighs about 170 lb. plus the weight of the spare.

I intend to run 32" to 33" tires, nothing larger. I also have a .5" Rokmen body lift.

I am looking at OME 2" springs with Nth Degree Mobility Rear Spring Relocators TJ/LJ Wrangler (https://www.nthdegreemobility.com/rear_spring_relocators_tjlj_wrangler) and Nth Degree Mobility 2" Coil Spring Spacers XJ/ZJ/TJ/LJ (https://www.nthdegreemobility.com/2_inch_coil_spring_spacers_xjzjtjlj).

I figure that between the OME springs and the Nth Degree Mobility parts I should have enough room for 33" tires.

I am also leaning towards all JKS suspension arms and trackbars.

My problem is picking the correct OME springs.

For the rear there appears to be two options:

2949 - JEEP UNLIMITED REAR HEAVY CONSTANT LOAD (220 TO GVW)
2996 - JEEP UNLIMITED REAR COIL SPRING (CONSTANT 400LBS)

I have the same basic issue with the front:

2934 - ZJ 5.2L V8 FRONT HEAVY LOAD (90-180LBS) - recommended by friend
2933 - FRONT (6 CYL.) HEAVY LOAD (90-180LBS)

I have not found any good description of the springs or their differences. I did find a document that explains this info but it is Greek to me.

View attachment 38501

My other thought is to go with a complete Nth Degree Mobility solution but their smallest spring is 3" and with the relocator I feel it will put be up to 4" of lift. Not sure I want to be that high. Then again I may not be that high based on the weight of the jeep.

Nth Degree Mobility Jeep LJ 3.0" Frequency-Tuned Rear Coil Springs (https://www.nthdegreemobility.com/jeep_lj_30_frequency_tuned_rear_coil_springs)

Nth Degree Mobility Jeep TJ/LJ 3.0" Frequency-Tuned Front Coil Springs (https://www.nthdegreemobility.com/jeep_tjlj_30_frequency_tuned_front_coil_springs)

As a side note I am thinking of running 4.88 gearing.

Thoughts?

In principle, your trying to understand spring rate as it relates to weight, do that in the end you get desired lift.

A 200lb spring rate means that for each additional 200lbs the springs will compress 1”. This is for a linear spring.

You need to know the weight you are trying to support at a given height, which you seem to know. Front is easier bc it doesn’t vary with gear or passengers. The rear could fluctuate, so you have to decide what weight you want to compensate for (loaded, unloaded or a compromise). Choose an appropriate spring which will give you ~4” of total lift. A 3” spring compressed 1” by weight is only 2”, plus your spacer or spring relocator adds 1 5/8”, plus your 1/2” body lift for a total of 4 1/8” Lift. If you suspect more weight choose higher spring rates or longer springs. You get the idea

 

[gg1]

FWIW, I just put an OME 2" lift on my Rubi and am running so called 33's, which are actually 32.8 I believe. I have plenty of room, but I do have the HD springs which are so stiff I can climb on my bumper and it hardly moves. Very stiff springs, so not the best ride. I don't have any gear being carried however, so I am going light which makes more sense to me. The lighter the better, IMHO. Never understood wanting to keep adding so much weight.

 

[JMT]

I have plenty of room, but I do have the HD springs which are so stiff I can climb on my bumper and it hardly moves. Very stiff springs, so not the best ride..

What shocks are you running?

 

[gg1]

What shocks are you running?

Oh sorry, the OME shocks. I panted them black because I don't like yellow. lol They don't move much.

I do want to point out if you are going to off road like Jerry B, then I would yield to his advice. My Rubi won't see the trails he is hitting, so for me my setup is okay.

Here is a picture of the front.

 

[ac_]

FWIW, I just put an OME 2" lift on my Rubi and am running so called 33's, which are actually 32.8 I believe. I have plenty of room, but I do have the HD springs which are so stiff I can climb on my bumper and it hardly moves. Very stiff springs, so not the best ride. I don't have any gear being carried however, so I am going light which makes more sense to me. The lighter the better, IMHO. Never understood wanting to keep adding so much weight.

that is weird because I am running the 2" with front and rear heavy shocks and mine rides pretty good, I am running 31's with 28PSI. Check you tire pressure it may be some of your stiff ride. Seriously I have the 2" heavies in the front and the 2 inch lights in the rear, but heavies shocks on all 4 corners and mine rides great. I have a winch in the front and nothing in the rear, I am talking not even a back seat.

In fact, I don't think I have ever heard of anybody ever complaining of the ride from a OME lift.

full disclaimer I was running all 4 heavies springs, but the rear gave me way too much lift so I swapped them out for the lights and it brought it back down, but honestly the ride was not different between the two springs only the height in my case.

Check your tire pressure seriously.

 

[Jerry Bransford]

I'm running both a 1" MML

FWIW, I just put an OME 2" lift on my Rubi and am running so called 33's, which are actually 32.8 I believe. I have plenty of room,

As above, 2" is not enough for 33" tires unless you never take it offroad or drive over dips/bumps in the road. It may look like you have enough clearance but it's not. At a minimum I'd at least add a 1" body lift to give your tires more clearance.

4" is the most commonly recommended lift height for 33's, I'd go nothing less than 3" for a Jeep that only sees smooth paved streets.

There are many charts like the below, and all recommend 4" for that size tire...

 

[T Crawford]

This is for an LJ why do you need to worry about a tranny crossmember lowering kit or motor mount lift.

 

[Chason]

So I am starting the build process on a LJ with a hardtop, Nth Degree Mobility tummy tuck and Poison Spyder rockers.. I have some thoughts on what suspension I want to use but have some questions about the different OME springs.

The LJ has both a heavy front and rear end. The front bumper weights about 85 lb. and the winch weighs about 95 lb. The rear bumper (swing out) weighs about 170 lb. plus the weight of the spare.

I intend to run 32" to 33" tires, nothing larger. I also have a .5" Rokmen body lift.

I am looking at OME 2" springs with Nth Degree Mobility Rear Spring Relocators TJ/LJ Wrangler (https://www.nthdegreemobility.com/rear_spring_relocators_tjlj_wrangler) and Nth Degree Mobility 2" Coil Spring Spacers XJ/ZJ/TJ/LJ (https://www.nthdegreemobility.com/2_inch_coil_spring_spacers_xjzjtjlj).

I figure that between the OME springs and the Nth Degree Mobility parts I should have enough room for 33" tires.

I am also leaning towards all JKS suspension arms and trackbars.

My problem is picking the correct OME springs.

For the rear there appears to be two options:

2949 - JEEP UNLIMITED REAR HEAVY CONSTANT LOAD (220 TO GVW)
2996 - JEEP UNLIMITED REAR COIL SPRING (CONSTANT 400LBS)

I have the same basic issue with the front:

2934 - ZJ 5.2L V8 FRONT HEAVY LOAD (90-180LBS) - recommended by friend
2933 - FRONT (6 CYL.) HEAVY LOAD (90-180LBS)

I have not found any good description of the springs or their differences. I did find a document that explains this info but it is Greek to me.

View attachment 38501

My other thought is to go with a complete Nth Degree Mobility solution but their smallest spring is 3" and with the relocator I feel it will put be up to 4" of lift. Not sure I want to be that high. Then again I may not be that high based on the weight of the jeep.

Nth Degree Mobility Jeep LJ 3.0" Frequency-Tuned Rear Coil Springs (https://www.nthdegreemobility.com/jeep_lj_30_frequency_tuned_rear_coil_springs)

Nth Degree Mobility Jeep TJ/LJ 3.0" Frequency-Tuned Front Coil Springs (https://www.nthdegreemobility.com/jeep_tjlj_30_frequency_tuned_front_coil_springs)

As a side note I am thinking of running 4.88 gearing.

Thoughts?

If you lived near me I would give you my ps rockers for half the price. I don't like how they mount using the factory body mounts.

 

[gg1]

As above, 2" is not enough for 33" tires unless you never take it offroad or drive over dips/bumps in the road. It may look like you have enough clearance but it's not.

Jerry, I would never argue with you for sure. I will run what I have and take some pictures. Even if I am a fool and made a mistake, I will still post the pictures because it would be educational for people here. I will tell you, I have WAY more into this Jeep than I ever imagined and I need to post about it for others that want to lower from a 5.5" lift. There is WAY more going on than I thought and I don't want others to make my mistakes.

As always thanks for taking the time to respond.

 

[JMT]

If you lived near me I would give you my ps rockers for half the price. I don't like how they mount using the factory body mounts.

Can you modify the bottom, weld another plate on and mount them directly to the tub? I was always turned off by PS using the body mounts.

 

[Chason]

Can you modify the bottom, weld another plate on and mount them directly to the tub? I was always turned off by PS using the body mounts.

I'm sure it's possible, shops around here charge to much to fab stuff up. It'd be cheaper to buy a welder & start practicing.

 

[JMT]

I'm sure it's possible, shops around here charge to much to fab stuff up. It'd be cheaper to buy a welder & start practicing.

I wish Rokmen would make their mercenary sliders again.

At least there’s still Genright and Savvy.