Add-a-Leaf Lifts and Part Numbers

[nasty610]

A long time ago in a galaxy far far away someone came up with the idea of using strips of bent metal as a spring. Not too long after that someone else put them under a 4wd and we ended up with leaf packs. Then this other guy decided if he shoved another leaf in there it would lift his 4wd. From then on that guy was famous.......well not really but something similar happened and we ended up with the Add-a-lead lift.

So how does it work? The answer is on Google somewhere but not in this thread.

Anyways, as far as I know there is only a couple places that sell an AAL specifically for Isuzu. At least they say it's specifically for Isuzu then charge out the butt for it. While it sucks that's the price to play in a vehicle the aftermarket doesn't support. Most of these are around half what the "Isuzu" specific AAL's cost.

Being the super nice guy I am I compiled a short list. Aftermarket companies are surprisingly tight lipped on their spring specs. Most of them are for 2.5" wide springs because SURPRISE!!!! most trucks and SUVs use 2.5" springs. Isuzu, and another much less famous brand that starts with a T, use 2.375" wide springs. There's a reason but again you'll need Google to find it. Just so everyone knows you CAN stick a 2.5" spring in a 2.375" pack. It takes 3-4 beers, lots of swearing and a hammer or big clamp. I may be wrong on the beer so buy at least a 24 pack.

Unlike my Coil Spring thread I'm can't tell you how much lift you'll get from a particular spring. The main reason is I don't know the weight on the rear axle of a 1g Trooper, Amigo or Rodeo. I'm going to make an educated guess on the Trooper. Just remember the key word in that sentence is GUESS. If you happen to know the weight on each axle of any of these vehicles post it or PM me.

Ok so I'm GUESSING a 1988-1991 Trooper has roughly 1510 lbs supported by the rear axle. Just so no one screams foul I used a highly scientific method and the v6 since the number was easy to find.

[Curb weight - engine weight] / # of axles - rear axle w/ brakes = weight on axle(RA)
[3370 - 350] / 2 - 200 = 1510

Keep in mind leaf packs get progressively STIFFER as they compress. I'm sure there's an equation to account for it but I DID NOT attempt to find it. This means all lift numbers should be on the low side.

The arch of the AAL will play a large role in how much lift you'll get. If two springs have an equal rate the one with more arch will always give more lift.

Another thing worth mentioning is that these springs can be trimmed down to increase their effective rate. That's why I included Pro-Comp P/N 13124-1. At 50.75" long it's more than 3" longer than a Troopers main spring. When cut down to 45" the rate jumps to 78.34 lbs/in. Take it down to 40" and the rate shoots to 111.54 lbs/in. So you're better off picking a longer spring with a lower rate then trimming it down to get the height you want.

When trimming a spring down there's a few things you can and CANNOT do. You ABSOLUTELY CANNOT use a torch to cut down a spring. Someone is going to contradict me on this and they are so full of s*** it's not even funny. Cutting a spring like that ruins the temper and it will fail, sometimes catastrophically.

The correct way to do it is with a saw of some sort. Once it's cut down you should use something to round the end off. A flapper wheel works best. This will help prevent it from eating into the springs it sits against. Before you blindly cut always run the numbers through a calculator. It'd be a shame to hack 7" off a brand new AAL only to realize the rate is way too high.

This is the calculator I use and it has proven pretty accurate.

A good starting point for the rate is 25-30% of the Stock Trooper rate. Without the overload it is 140.77 lbs/in. We don't count the overload because it should only come into play under heavily loaded conditions

ALWAYS USE A BRAND NEW CENTERING PIN
Remember if it's in big bold letters it's probably important.

BDS
114202--arch 6.75"--length 42"--width 2.5"--thickness .26-- 51.68 lbs/in---1.4" lift

Rancho
Rs60622--arch 7"--length 45.75"--width 2.36"--thickness .26--rate 37.75 lbs/in---1.1" lift
Rs60613--arch 6.75"--length 44.76"--width 2.5--thickness .26--rate 42.7 lbs/in---1.25" lift
Rs60632--arch 6.25--length 42.75"--width 2.5--thickness .26--rate 49 lbs/in---1.3" lift
Rs60013--arch 8.65"--length 45.65--width 2.5"--thickness .32"--rate 75 lbs/in---1.8" lift

Pro-Comp
13160-1--arch 6.75--length 45--width 2.5-- thickness .25--rate 37 lbs/in---1" lift
13124-1--arch 7.62--length 50.25--width 2.5--thickness .32--rate 54 lbs/in
13120--arch ???--length 21"--width 2.375"--thickness .25"?--rate 349.17 lbs/in

[gwana66]

This is why I love this place. Great info!

[Beamer]

Nice work!

[geoffinbc]

I second the no torch policy. It will anneal the steel and make it useless. Use a zip cut. It's more accessible anyway. If you have a fancy dancy shop you could set a spring up on a water jet table. Under water plasma or laser would be acceptable too. But seriously those options are crazy since we're talking a 2.5" long cut lol.

[oldestisuzuist]

I second the no torch policy. It will anneal the steel and make it useless. Use a zip cut. It's more accessible anyway. If you have a fancy dancy shop you could set a spring up on a water jet table. Under water plasma or laser would be acceptable too. But seriously those options are crazy since we're talking a 2.5" long cut lol.

I used a portable band saw to cut the last two springs I shortened. A reciprocating saw would probably also work. Yes, they are harder than mild steel, but not excessively so. The advantage of a saw over the zip disc is no sparks.

[leftarmtan]

I'm using the Pro Comp EXP-13120 add a leaf (short length).$36.99 for the pair,worked well for my application which is 89' Trooper rear springs up front SAS.

[nasty610]

I didn't see that one when I pulling part numbers. Any chance you know the length and thickness?

[leftarmtan]

21"long 2 3/8" wide

[nasty610]

Any chance you can get the thickness as well?

[leftarmtan]

Looks to be the same thickness as stock springs,about 1/4"

[nasty610]

If anyone has installed an AAL that's NOT on the list please PM or post the Part Number, Length, Width and Thickness. I'd like to add to this list and its dang near impossible to get this information from the retailers.

Anyone that installs or has installed one from the list post up. How much lift did you net? Does it ride well or like a truck? How much, if any, did you trim? Pictures would be awesome too.

[tpuck]

I'm using the Pro Comp EXP-13120 add a leaf (short length).$36.99 for the pair,worked well for my application which is 89' Trooper rear springs up front SAS.

Did you measure the total amount of lift these gave you?

[leftarmtan]

I'm using the Pro Comp EXP-13120 add a leaf (short length).$36.99 for the pair,worked well for my application which is 89' Trooper rear springs up front SAS.

Did you measure the total amount of lift these gave you?

I'm using them in the front,so would be different.I would guess about an inch

[nasty610]

I'm using the Pro Comp EXP-13120 add a leaf (short length).$36.99 for the pair,worked well for my application which is 89' Trooper rear springs up front SAS.

Did you measure the total amount of lift these gave you?

I can't imagine using those would result in anything but a super stiff ride. The factory spring rate with the overload has about the same rating. Doubling it would cause the suspension to not absorb bumps at all. You'll end up bouncing over everything unless you have a lot of weight in the back. It works for the front because the front of the truck is so much heavier.

[tpuck]

The truck seems to be really loose in the rear as it is. There aren't any broken springs in the packs, but they could be fatigued. I think these may just help.

[tpuck]

I'm using the Pro Comp EXP-13120 add a leaf (short length).$36.99 for the pair,worked well for my application which is 89' Trooper rear springs up front SAS.

Did you measure the total amount of lift these gave you?

I can't imagine using those would result in anything but a super stiff ride. The factory spring rate with the overload has about the same rating. Doubling it would cause the suspension to not absorb bumps at all. You'll end up bouncing over everything unless you have a lot of weight in the back. It works for the front because the front of the truck is so much heavier.

I'm not trying to argue at all, but I have seen reviews of people using these on some not so heavy vehicles (like rangers). Most say the ride isn't changed that much. Who knows though.

I am trying to find an add a leaf for my old Trooper that will lift it 2 inches or so. Less is better than more, but I wan't to be between 1.5" and 2". I also don't have the tools to cut the springs.

I really want to try the 13120 Pro comp, but I guess I shouldn't waste my time. The search continues..

[nasty610]

Did you even bother looking over the list of add-a-leafs I made? All the information you need to make an extremely informed decision is right there all you have to do is pick one and order it. Please think about what you want then READ THE FIRST POST even it's only the list of springs.

[tpuck]

Did you even bother looking over the list of add-a-leafs I made? All the information you need to make an extremely informed decision is right there all you have to do is pick one and order it. Please think about what you want then READ THE FIRST POST even it's only the list of springs.

Of course I looked at your list. The list isn't complete and not all the springs listed are available. So if I want to get a 2" lift I need to look other places than your list. I am curious why people would be using that 13120 spring on rangers without losing the ability to absorb shock. The Ford Ranger is 1380lbs on the rear axle and my Trooper is 1320 on the rear.

Is it possible that the spring rate is distributed over the whole pack, and since it is a shorter spring it cannot act on the entire arch of the spring pack? I have no clue as I am just coming into my car knowledge. It is just odd that people can get a lift on their ranger but don't complain of over stiffness.

I'm just trying to find my way, but rest assured, I am reading and using the search function. I usually search for days before I post a question. I appreciate any help I can get while I wash away the noob that is my current understanding of cars and trucks.

Thanks

[nasty610]

Yes the entire weight of the vehicle is spread out over the entire length of the spring. That’s part of why a Ranger with longer springs will ride softer with a higher spring rate then a trooper with shorter springs and a softer rate.

No I didn’t make an all exclusive list because it’s a waste of time. I covered a 1-2” lift with an add-a-leaf from reputable companies. There are reasons you shouldn’t do more then a 1-2” lift with a add-a-leaf or shackles. Most of them have to do with making your vehicle ride like crap.

[tpuck]

Yes the entire weight of the vehicle is spread out over the entire length of the spring. That’s part of why a Ranger with longer springs will ride softer with a higher spring rate then a trooper with shorter springs and a softer rate.

No I didn’t make an all exclusive list because it’s a waste of time. I covered a 1-2” lift with an add-a-leaf from reputable companies. There are reasons you shouldn’t do more then a 1-2” lift with a add-a-leaf or shackles. Most of them have to do with making your vehicle ride like crap.

Yeah, I want 2" max from an add a leaf. It's just hard to find which one I should use. The one on your list that is 1.8" of lift isn't available anymore and the rest are much lower. I'm new to calculating info having to do with springs, so am having trouble figuring how much lift I will achieve from a particular spring. I'm also on a budget and am just trying to get this amazing $500 truck snow worthy. I need to carry things in the rear and make it through snow, so I figure an AAL would be a good way to get it done.
Thanks

[tpuck]

So do you think these would also be too stiff?

Free Arch: 6.75”
Length: 38.38”
Width: 2.5”
Thickness: .32”

with your calculator I got 126.27 as the spring rate.

The spring rate listed for my Trooper is 2.89/6.09 unclamped and 3.15/6.63 clamped. That is kg/mm..

161.83/341 unclamped 176.4/371.26 clamped. That is lb/in

So is a helper spring that is almost 3/4 the rating too much? Or will it lift it and stiffen it just slightly. My truck needs to be balanced between road driving and off road as I live out forest service roads, and the forest service is currently defunded and not maintaining at all. So a little stiffer would be nice for the road, but I don't want to loose all my flex, seeing as I have very little.

[nasty610]

Most of the springs I listed have a rate around 50 lbs/in and potnetionally lift a Trooper 1-1.5”. I’d say a spring that’s 2.5 times stiffer is going to lift it more then 2” and ride like garbage. Most of the springs I listed are long with a lowish rate. I intentionally did that so they could be trimmed which raises the rate. Pick something with a rate 40-60lbs with a descent amount of free arch then see how it rides. If it needs to be stiffer pull them out and trim them 1/2” on each end. There is no one size fits all with this kind of mod. You pick one that’s close and tune to your needs.

[tpuck]

Most of the springs I listed have a rate around 50 lbs/in and potnetionally lift a Trooper 1-1.5”. I’d say a spring that’s 2.5 times stiffer is going to lift it more then 2” and ride like garbage. Most of the springs I listed are long with a lowish rate. I intentionally did that so they could be trimmed which raises the rate. Pick something with a rate 40-60lbs with a descent amount of free arch then see how it rides. If it needs to be stiffer pull them out and trim them 1/2” on each end. There is no one size fits all with this kind of mod. You pick one that’s close and tune to your needs.

Alright I think I've got it. Last question, I promise. Do you have to put the AAL just above the overload spring, or can it go just below the main spring? I ask because the mainspring in my Trooper is 47" and the bottom spring is 34". So if I have to put the spring just above the overload, it changes my options.

Thanks for your time

[nasty610]

Any leaf added need to be shorter then the leaf above and longer then one below.