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Lift Springs for 92-02 Troopers and 98-04 Rodeos

123K views 189 replies 41 participants last post by  Stormtrpr 
#1 ·
I've redone this to make it easier to find a spring for the desire lift height. There's now a Trooper and Rodeo section. Each has 2 categories for zero load and 1000bs. I looked through the BDS catalogue to get some better springs and keep the rates within reason. Sorry there's not more for the Rodeo guys. I'm going to search around in some other catalogues for more springs. Also the BDS catalogue didn't list end type so look them up before blindly ordering.

There's seems to be some confusion about Progressive vrs Straight rate springs. In a nut shell straight rate springs only have one rate over the length of the spring. That makes them ideally suited for constant loads like say 1000lbs all the time. Progressive springs will have at least 2 rates but some aftermarket springs will have 3-5 rates. Progressive springs are best suited vehicles that see multiple load conditions. Like daily commuter without a load during the week and 1000lbs of gear on the weekend for adventures. Regardless of which spring you pick there will be a difference in height from unloaded to loaded. The real benefit of progressive springs is the softer ride when unloaded.

**According to the OME catalogue the OE Trooper spring rate is 160 lbs/in. Free length is 16".

TyCobb2001 provided the weight numbers for his Trooper:
92-02 Trooper curb weight 4460 lbs
Front axle(FA) 2150 lbs
Rear axle(RA) 2310 lbs

Neutron provided weight numbers for his 2000 Rodeo LSE
98+ Rodeo curb weight 4280
Front axle(FA) 2200 lbs
Rear axle((RA) 2080 lbs

Jerry(jlemond) provided axle and brake assembly weights:
12b axle weights (AW)
87-91 -- 160 lbs
92-94 -- 170 lbs
95-97 -- 180 lbs
98-02 -- 190 lbs
Brakes -- 20 lbs/side or 40 lbs total

D44 axle weight (AW)
Coil sprung -- 175 lbs (remember this is a rough number)
Brakes -- 20 lbs/side or 40 lbs total

Basic Load Equation
RA weight - (AW + Brakes) + Cargo + People = Load on RA

So using the numbers for my Trooper
- [ ] 2310 - (180 + 40) + 64 + 500 = 2654 lbs

The equation for this part is:

Load / (Spring Rate x 2) = Inches of sag
or
2654 / (158 x 2) = 8.398"

With a 2654 lbs load on the rear axle using the CC784 springs I would get 8.4" of sag. Now everyone every one wants to know how this number gives you the amount of lift. That's a little tougher since you need to subtract the Sag number from the free length of the coil to get the load height. Then figure everything out for stock. Once that's done you need to subtract your Lift Spring load height from your Stock load height. If the number comes out negative then the spring will LOWER your truck.

Stock would be:
2654 / (160 x 2) = 8.293" sag

Free length - Sag = Load Height
16" - 8.293" = 7.707"

CC784
2654 / 158 x 2 = 8.398"

18.6 - 8.398 = 10.202 Load Height

Overall lift is:
CC784 - Stock = Amount of Lift
10.202" - 7.707" = 2.495"

So with the same load a Moog CC784 will lift a Trooper 2.5" over a stock coil. Now I need everyone to remember that these numbers are estimates and will give you a good idea how much lift a given spring will provide. Unless you take the time to weigh everything yourself your REAL WORLD numbers will vary from the number you get here.

I've already done the math for each spring to determine the lift height. These are ESTIMATES and your real world numbers will be different. BE REALISTIC WITH THE LOAD YOU PLAN TO CARRY. Anything with a spring rate OVER 250lbs is going to ride like crap without a load. The chart reads as follows:
Brand--Part #--free length--spring rate--lift

Stock Trooper 92 thru 97--16"--160lbs/in
Stock Trooper 98 thru 04--180lbs/in
Stock Rodeo--14"--160lbs/in

Stock Trooper replacement
92-97 Trooper
Moog Cc217--16.15"--155lbs/in--variable rate***requires pig tail cut off
98-04 Trooper
BDS 034209--16"--180 lbs/in

Trooper Lift Springs with ZERO load

2-3" lift
Moog Cc812--16.3"--245lbs/in--variable rate--2.2"***requires pig tail cut off
Moog cc784--18.6"--158 lbs/in--lift 2.5"
BDS 034409--17.625"--200 lbs/in--lift 2.9"

3-4"
BDS 034211--17.25"--240 lbs/in--lift 3.5"
Moog 6187--17.5"--243lbs/in--lift 3.7"
BDS 034411--19.75"--175 lbs/in--lift 4.3"

4-5"
Moog cc814--17.5"--271 lbs/in--lift 4.2"
BDS 034301--18.5"--240 lbs/in--lift 4.7"
Moog cc816--18.25--271 lbs/in--lift 5"
BDS 034451--20.5"--175 lbs/in--lift 5"
BDS 034619--20.375"--180 lbs/in--lift 5"

5-6"
BDS 034658--19.625"--200 lbs/in--lift 5"
BDS 034452--20.13"--240 lbs/in--lift 6.3"

6-8"
BDS 034353--20.875"--240 lbs/in--lift 7"
BDS 034611--21.75"--175 lbs/in--lift 7"
BDS 034651--21.875"--225 lbs/in--lift 7.75"

8-10"
BDS 034652--21.75"--240 lbs/in--lift 8""
BDS 034653--22.875"--240 lbs/in--lift 9"
BDS 034852--23.75"--240 lbs/in--lift 10"

Trooper Lift Springs with 1000lbs load

0-2" lift
BDS 034409--17.625"--200 lbs/in--lift .5"
Moog Cc812--16.3"--245lbs/in--variable rate--.7"***requires pig tail cut off
BDS 034211--17.25"--240 lbs/in--lift 1.3"
BDS 034411--19.75"--175 lbs/in--lift 1.5"

2-3" lift
BDS 034451--20.5"--175 lbs/in--lift 2.2"
Moog cc814--17.5"--271 lbs/in--lift 2.3"
BDS 034619--20.375"--180 lbs/in--lift 2.3"
BDS 034301--18.5"--240 lbs/in--lift 2.5"
Moog 6187--17.5"--243lbs/in--lift 2.9"
Moog cc816--18.25--271 lbs/in--lift 3"

3-4"
BDS 034611--21.75"--175 lbs/in--lift 3.5"

4-5"
BDS 034452--20.13"--240 lbs/in--lift 4.25"
BDS 034658--19.625"--200 lbs/in--lift 5"
BDS 034353--20.875"--240 lbs/in--lift 5"

5-7"
BDS 034651--21.875"--225 lbs/in--lift 5.575"
BDS 034652--21.75"--240 lbs/in--lift 5.8"
BDS 034653--22.875"--240 lbs/in--lift 7"
BDS 034852--23.75"--240 lbs/in--lift 7.85"

Rodeo Lift Springs with ZERO load

0-2"
Moog Cc721-- 14.16--182 lbs/in--lift .85**requires pigtail cut off
Moog Cc217--16.15"--155lbs/in--variable rate--lift 2"--***requires pig tail cut off
BDS 034209--16"--180 lbs/in--lift 2.65"

2-4"
Moog Cc247--16.5"--161lbs/in--variable rate--lift 2.6"
BDS 034319--17"--180 lbs/in--lift 3.65"

4-5"
Moog Cc812--16.3"--245lbs/in--variable rate--lift 4.3"***requires pig tail cut off
Moog Cc784--18.6"--158lbs/in--variable rate--lift 4.5"***requires pig tail cut off
BDS 034419--18"--180 lbs/in--lift 4.65"
BDS 034208--15.63"--200 lbs/in--lift 4.75"
BDS 034311--18.875"--160 lbs/in--lift 4.875"
BDS 034202--18.375--180 lbs/in--lift 5"

5-6"
BDS 034211--17.25"--240 lbs/in--lift 5.2"
BDS 34302--19.5"--158 lbs/in--lift 5.4"
BDS 034411--19.75"--175 lbs/in--lift 6.25"

Rodeo Lift Springs with 1000lbs load

0-3"
BDS 034208--15.63"--200 lbs/in--lift .5"
BDS 034319--17"--180 lbs/in--lift 1"
BDS 034419--18"--180 lbs/in--lift 2"
Moog Cc812--16.3"--245lbs/in--variable rate--lift 2.3"***requires pig tail cut off
BDS 034202--18.375--180 lbs/in--lift 2.375"

3-4"
BDS 034211--17.25"--240 lbs/in--lift 3"
BDS 034411--19.75"--175 lbs/in--lift 3.5"
 
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#2 ·
Might be good information for Planet Wiki.
 
#3 ·
oh wow! thank you! I just emailed OME a few days ago asking them what the spring rate for the 929 and the 919 are. I've been wanting to buy 929s but for 200 bucks no thanks! I've been trying to match the spring rate with a moog spring.
 
#4 ·
Most people say they want X amount of lift then purchase a spring that their chosen vendor says lifts their vehicle that amount. While this works it's not really the best method. There's several factors that should be considered: how will your vehicle be used, how much of a load will it carry and how it will handle. The amount of lift you get should be considered after these questions are answered or you'll most likely end up with a vehicle that looks cool and rides like crap.

How it will be used?--
Ask yourself how you will really use your vehicle: towing, off roading, commuting, soccer mom ect. You should try to setup your vehicle for how it will be used 80% of the time. If you're on the trail 80% of the time you need a different spring then if you spend 80% of the time on the street.

How much of a load will it carry?--
Honestly how much do you normally load your vehicle with? This ties into how it will be used. If you spend 80% of your time unloaded then you really don't need the heaviest spring rate you find.

How will it handle?--
This is really a byproduct of the first two questions. If you selected a spring that works for 80% of your driving then your truck should handle as well, if not better, then it did stock.

Ok so now you've answer the three questions above what next? Well you need to do some math. Figure out what your truck weighs 80% of the time, a good guess here works fine, then decide how much lift you want. Do all your estimates with a full tank of gas. If your truck weighs 5000 lbs cut that number in half. It's not exact but, 2 axles each one supports half the weight which should be close enough for a SUV. So now we have 2500 lbs over the rear axle what spring do we use? Pick the spring that you think will work. For this example we'll use Moog CC784. The 784 has a rate of 158 lbs/in and a free height of 18.6". So to figure out how much this spring will compress we have to take the rate and multiply by 2 because there are 2 springs. Then we divide the load(SUV weight) by the rate(lbs/in) and then subtract that number from the free height.

The equation should look like: spring free height - (vehicle axle weight) / (spring rate x 2) = spring loaded height

My example: 18.60 - 2500 / (158 x 2) = 10.688

Most vehicles have more weight over the front axle then the rear so just dividing your vehicle weight by 2 won't be exact. To get closer to a real number you'll need load your vehicle with a normal load then find a truck weigh station. Most heavy truck fuel stations have them and they are available to the public for a small fee. These scales have the ability to weigh each axle independently. Once you have the numbers for each axle you select the axle you need springs for and input the numbers into the equation.

*****I have to mention this now or someone will cry foul later. The weigh station is going to give you total weight over the axle which is going to skew the equation to show a lower loaded spring height or less lift. This is because the axle and anything attached(wheels, brakes, driveshaft, ect) to it is consider UNSPRUNG weight. In other words the springs DO NOT support the weight of these components. If you need a better explanation of this please Google search "unsprung weight" and do a little reading.*****

What happens when you find a spring that works for the load you want but is not the correct length to give you the amount of lift you desire? This depends on whether the spring is too long or too short. If it's too short you should honestly try to find a longer spring with the same rate. Chances are though you'll be stuck trying to use the shorter spring. At that point you'll need to purchase a set of spring spacers to give you the desired lift. There's quite a few on the market and you ARE NOT required to buy a set that a vendor says are Isuzu specific. Our springs are 4" ID so purchase springs spacers designed for 4" ID springs. Still not sure which spacers to get, well most Jeeps use 4" ID springs so spacers for those will nicely. Now if the spring you've selected is too long just cut it down. DO NOT USE A TORCH TO CUT SPRINGS. They are heat treated and using a torch will ruin them. Use a cut off wheel and only cut 1/4 - 1/2 a coil at a time until you get to the correct length.

Another thing to remember is balance between the front and rear suspension. If you're spring rate in the rear is too much higher than the front any bump the rear hits will actually transmit the force to the front suspension. Mainly this applies to how your vehicle will ride unloaded if you've selected a spring based on a loaded condition. Think of it like riding around in a 1 ton Dodge/Ford/Chevy and driving over speed bumps. The front goes squish while the rear kicks you in the a**. Some people will think this is acceptable while others won't be very happy. If you're going to be increasing the rear spring rate by 50 lbs/in or more it would be highly recommended to upgrade to heavier front springs. For our Isuzu's this would mean purchasing torsion bars from Indy, Calmini or Sway-a-way.
 
#5 ·
My 1995 Isuzu Trooper LS with plastic fender flares has these springs as Original Equipment from Isuzu.

Inner Dia 4.1875 in
Bar Dia 0.509 in - 0.514 in or 12.92 mm - 13.05 mm
Rate 160 lbs/in
Free Height 16.0 in
End Style tangential / tangential

If 160 lbs/inch is the correct spring rate, I think I would like 180 or 200 lbs/inch Spring rate.

And a free length of 18.5" inches would be nice...
 
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#6 ·
If anyone can get me the free height and bar diameter for Rodeo and 3/01+ Troopers I can add that information to the list.
 
#7 ·
Any one try getting a 1993-98 Jeep Grand Cherokee ZJ 3" lift front coil spring, and cut it to a little at a time to desired height, while removing the pig tail end... To me this seems like a good option to raise the rear end...
 
#8 ·
Personally I don't feel that's a good idea for a couple reasons. First reason is stock ZJ springs will give you a 2.5-3" lift so buying a set 3" lift springs for a ZJ would give you a total lift around 5.5-6". That's a lot of cutting and you can't match that amount of lift with the front suspension. Second reason is most retailers want $150-200+ shipping for a set of springs that you would still need to cut. You'd be better off purchasing OME springs and leaving them stock. Most of the aftermarket Jeep springs start at 185 lbs/in and run up to 250 lbs/in. There's quite a few springs on the market that fit within that range and can be purchased for $80+ shipping or less. If you're looking for a specific rate/free height combination you should look up 4" ID circle track springs. They come in a wide variety of rates, free heights and ID's. I checked a bunch of vendors and it seems that circle track springs don't get any bigger than 3.63" ID so those are out. What I did find is that 5" OD springs will work and it's what aftermarket manufacturers like Eibach use for springs sizing above the 3" mark. Just be conscious that if the OD stay constant at 5" that means you have to subtract the bar dia to get the ID. This means if you buy a very heavy rate coil that has a large bar dia your ID could end up smaller than 4".
 
#9 ·
I was under the impression that you have to cut off the pig tail end on the Grand Cherokee Springs... Then you end up with 2 tangential ends and a 1" longer spring...
 
#10 ·
Yes you have to cut the pigtail off but you end up with two square ends. If you use springs designed to lift a ZJ 3" you'll end up with a spring much more than 1" longer. When you use OE ZJ springs and cut off the pigtail you end up with a spring 1-2" longer than a stock Trooper spring.
 
#11 ·
MOOGcc762 is the way to go,espically from a 97/98 grand Cherokee. I do believe are and extra inch longer more than 93-96. Cheapiest 3" ever and lover at 100$ a pair. how could ya go wrong?
 
#12 ·
The CC762 has inner diameter of 5.984" and will not fit the mounting pad on an Isuzu. I think you meant CC782.
 
#14 · (Edited by Moderator)
just wanted to update this thread; i purchased and installed some Moog CC784 springs on my passport this last weekend. it went very well! they cut very easily with a wheel, but even a hacksaw would have worked. i ended up cutting the pigtails off, and then cutting an additional 1-1/4 (full and a quarter coil) spring off of the more loosely wounded side to get about the height i wanted.
sidebyside.jpg

lifted.jpg


i did this mainly so i could tow my boat more easily, and it definitely worked. i now sit higher loaded than i did unloaded at stock, and the ride is phenomenal. huge upgrade all around, and for less than half what OME's cost, these were $71 shipped. i do plan on cranking the torsion bars about an inch, then call it good.
one thing, i tried to do this just one side at a time, but found that when i cut and installed the opposite spring, it completely threw off my measurement that i had. thankfully its easy enough to do them both at the same time, and will give you a more consistent measurement in the end.
mikey
 

Attachments

#15 ·
here.....
 
#16 ·
My 2002 Trooper was bottoming out easily with normal driving. I installed Rancho 5000 shocks and its better but still bottoms out. I tow the 2900lb trailer in the photo I attached. It tows fine but could use better springs.

What would OME 2919 do to the height in the rear? Do I need coil spacers or just the coil springs alone? Do I have to raise the front as well?

Also, I installed new front Sway bar bushings that helped a ton with body roll. Are there rear (or any other) bushings that I should replace?

Thanks for any advice!

This picture was taken after Rancho 5000's were installed.


This pic was taken before the Rancho Shocks.


 
#17 ·
If you install the OME 919 springs it will raise the rear end. Without raising the front of the Trooer you'll end up with a raked look where the rear is substantially higher than the front. The coil spacers will add additional height to the rear and have nothing to do with load carrying capacity. Personally I would purchase one of the springs listed in the first post based on the load you'll be carrying. If you don't want to lift your Trooper look into Air Ride helper springs. They install inside your coils and can be inflated when you need additional load capacity.

From you description though it sounds like you worn out springs. Either purchase the OME springs and deal with the lift or purchase a set from the list that has a rate 160-180 lbs/in and then cut it down to give the desired ride height.

Unfortunately you're before/after Rancho shock pics aren't much help since one is unloaded and the other is loaded. Generally though by installing new shock you only control the speed at which the suspension extends and compresses not where you ride within the travel.

You should be able to purchase a set of 19mm(7/8") diameter poly sway bar bushings at Auto Zone or Advance Auto. They may not be on the shelf but can be ordered. Several people on here have stated they don't make much of a difference when compared to the front. I drove my Trooper for a couple weeks with just the fronts installed. When I finally got around to installing the tears my Trooper cornered much flatter. Just my .02 but my wife even commented on the difference.
 
#18 ·
I think I might buy the OME 919's and raise the front. Do you know of anyone doing that and staying with the stock-size tires? I'd like to see what that looks like if anyone knows of pics of a trooper like that.

I don't want the raked look but if I raise front and back w/ stock tires, I don't want the trooper to look like a roller skate! haha
 
#19 ·
nasty610 said:
...

OME 2919 Trooper Heavy load 25 mm lift
Dia .59 in/15 mm
Rate 200/280 lbs/in
Free height 16.92 in/430 mm

OME 2929 Trooper Heavy load 20 mm lift
Dia .62 in/16 mm
Rate 240/300 lbs/in
Free height 16.53 in/420 mm
I'm glad I found this thread. I was under the impression that the 929s would give me the same (if not more) lift than the 919s but be stiffer and have a higher load capacity. My rig is 80% trail and will rarely tow anything. If I understand the above the 919s will give me more lift? If i'm looking for more lift vs. load capacity would the 919s be better suited for me?

Thanks,
Ashby
 
#20 ·
Despite what the ARB info says, both the 919 and 929 will give you about 2" lift.
 
#21 ·
I believe ARB uses the rated load to get the advertised lift. It's the only thing I can think of that would account for the dramatic difference between what's advertised and is seen in real life.
 
#23 ·
Yes, definitely
 
#24 ·
This is a great thread. Just bought a 98 rodeo and I was looking for some better spring options. Thanks to the OP!
 
#25 ·
I just installed front & rear polyurethane bushings, OME 2919 Springs, and Rancho 5000 shocks. It still has stock size Michelin tires. I've had Rancho 5000 and Rancho 9000 shocks on various vehicles in the past. I went with the 5000's on the Trooper because I remembered that the 5000's are about equivalent to a 9000 shock on setting #5 out of 9 (1=soft ride 9=stiff ride). I didn't realize how heavy this little trooper actually is. If I had to do it again I would go with Rancho 9000's for sure! I loved having the option to simply turn a little knob on each shock for each load size and terrain.

I have not turned the torsion bars yet to raise the front which I plan to do soon. The rear is higher than it used to be for sure but I don't think it looks too weird with the front being lower than the back. I am extremely happy that the rear no longer bottoms out! I am disappointed, however, that the front seems to bottom out (and I know from experience that this would not happen if I had Rancho 9000 shocks on a higher setting). I hope that turning the torsion bars will fix this issue!

Can anyone tell me if turning the torsion bars and lifting the front will take care of the bottoming-out issue?

Thanks.
 
#26 ·
Yes increasing preload on the torsion bars will lift the front and will stop it from bottoming out.
 
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