Isuzu SUV Forum banner

Longer Shocks for your Lifted Isuzu

50K views 48 replies 22 participants last post by  Fireboxpup 
#1 · (Edited by Moderator)
Welcome ladies and gentlemen to my personal pet peeve on the Planet. SHOCKS.

Every week or two someone asks what shocks they should run. Without fail "Buy OME or Bilstein" shows up within the first 5 posts. Nothing against either but most people don't realize there are other shocks available. The big thing that catches most people's attention is the 46mm piston and velocity sensitive valving. Because of marketing hype, you'd think you need a big-name shock to get those features. The truth is most of the better OE replacement shocks have a 42-46mm piston and can be purchased locally. Most of them go for less than $100 per shock as well and there's no shipping charge.

While we're on the subject of longer shocks I want to mention post extensions. To put it simply they are garbage. Don't waste your money just buy the right shocks the first time.

Ok now there are a few people on here that understand hydraulics but for those that don't, I'll explain velocity sensitive valving. When you force fluid through a hole or around a shim stack there's a certain amount of resistance that's proportional to how hard you push. The harder(faster) you push the more resistance there is. Now when your tire smashes into an obstacle it forces the shock to compress quickly which creates lots of resistance but hit the same obstacle very gently and there's very little resistance. BOOM velocity sensitive. The cheapest POS shock on the market is velocity sensitive.

The piston plays a major role in how shock rides. Without getting technical a larger diameter piston will always ride better than a smaller one. This holds true even with stiffer valving in the larger piston. Stock Isuzu used 30mm front and 25mm rear so it shouldn't be harder to find something better.

So how do I plan to help the beleaguered members Planet Isuzoo? The same way I always do with cheaper alternatives.

I looked in my 96-97 Trooper FSM for the OE lengths of the shocks. Then I had to scour, well Google did, the Internet for the 1g Trooper and Rodeo numbers. 1g Troopers and Rodeos share the same rear shock so it made things easier. Something I didn't realize is that Isuzu spec'd the same size shock for every single front end from 81 Troopers to 04 Rodeos. Guess you don't mess with a good thing or they were too cheap to do something better.

Now I selected all these shocks because they are longer than stock Isuzu shocks. The downside to this is you have to lengthen your bump stops. If that's a problem if suggest not lifting your vehicle. They also have more overall travel to increase articulation.

To calculate how much to move your bump stop you need to subtract the compressed length of the stock shock from the compressed length of the shock you want to use. So if your stock shock has a compressed length(CL) of 12" and the shock you want to use has a CL of 15" then you need to move your bump stop down 3". The goal is to not have your shock be the limit.

New CL - Old CL = amount to move bump stop
15 - 12 = 3

One other thing I should mention is the shock mounts. I checked to make sure they are the right style but they may need work to fit. Such as a 1/2" bushing needs to be drilled out to 3/4" for a 92-02 Trooper. The bright side though is that you can buy any of these at AutoZone, Advance or Napa. Possibly with a lifetime warranty. Make sure to check them in the store BEFORE you leave.

There are a few front shocks to choose from. The major challenge is that we already have one of the longest travel front shocks of all the OE's. Just about everyone uses a 3-4.5" shock on their IFS. Isuzu uses a 5.1" travel shock. The ones that do have more are way too long to work.

Ok I've completed the list. I included a few full size truck shocks. They should only be selected if you're constantly hauling a load. Remember most of these will need minor work to fit.

92-02 Trooper shock mounts
Front upper mount stud---lower mount 12mm X 32mm
Rear upper mount 14mm--upper bushing 38mm wide--lower mount 18mm--lower bushing 40mm wide

81-91 Trooper & 92-97 Rodeo shock mounts
Front upper mount stud--lower mount 12mm X 32mm
Rear upper mount stud--lower mount 14mm--lower bushing 33mm wide

Front Shocks ALL models and years
2/98-06 Toyota Land Cruiser front shocks--ext bump stop 1"--reduce droop stop 1"--may max out CV
02-09 Hummer H2 front shocks
92-96 Ford F-150 forward of axle front shock--ext bump stop 1"--reduce droop stop 1"--May max out CV
03-05 Ram 1500 front shocks

Bilstein
5125 series
33-230405 stock length shock

92-02 Trooper Rear Shocks ONLY
69-86 Toyota Land Cruiser rear shocks--may need to ext bump stops up to 2"
84-89 Toyota 4Runner Rear shocks--ext bumps stops 1.5"
83-88 Toyota pickup 1 ton--ext bump stops 1"
99-05 Land Rover Discovery Series 2 rear shocks--ext bump stop 1.5"
99-04 Jeep G Cherokee rear shock--ext bum stop 1"
05-10 Jeep Grand Cherokee rear shock--ext bump stop 2.5"
06-10 Jeep Commander rear shock--extend bump stop 2.6"
85-05 Chevy Astro rear shocks--ext bump stops 1"
98-00Ford Ranger rear shocks--ext bump stops 1"
97-03 F150 rear shocks--ext bumps 1.5"--good for heavy loads
04-08 F150 rear 2wd shocks--ext bump stops 2.5"
01-12 Ford Ranger--there's several options look them up. All are rear shocks
85-95 Nissan Pathfinder rear shocks--ext bump stops 1"
85-97 Nissan D21(hardbody) rear shocks--extend bump stops 1"
98-04 Frontier 4wd rear shocks--extend bump stops 1"
98-04 Pathfinder & 99-04 Xterra are the same as Frontier
97-11 Dodge Dakota rear shocks--ext bump stops 2.75"

Fox Racing--all shocks have 1/2" mount holes
985-24-003 stock length internal reservoir shock
985-24-004 8" travel internal reservoir shock
985-24-050 stock length external reservoir shock
985-24-051 8" travel external reservoir shock
985-24-052 10" travel external reservoir shock
985-26-050 stock length external reservoir shock w/ compression adjusted
985-26-051 8" travel external reservoir shock w/ compression adjusted
985-26-052 10" travel external reservoir shock w/ compression adjusted

Bilstein
5125 series
33-062518 stock length shock 255/70 valving
33-233970 7" travel shock 255/70 valving
33-230313 8" travel shock 170/60 valving
33-185590 8" travel shock 255/70 valving

5165 series external reservoir
33-187861 stock length shock light valving
33-187885 stock length shock heavy valving
33-176223 8.8" travel shock light valving
33-176230 8.8" travel shock heavy valving

82-91 Trooper & 92-97 Rodeo Rear ONLY
80-89 Toyota Land Cruiser Front shocks
91-98 Toyota Land Cruiser rear shocks--ext bump stops 1"
1/98-06 Toyota Land Cruiser Rear shock--ext bump stops .5"
00-06 Toyota Tundra 4wd rear shocks-.5-1"
08-15 Toyota FJ Cruiser rear shocks-ext bump stops 1"
07-16 Toyota Tundra Shocks--ext bump stops 2"
99-06 Mitsubishi Montero rear shocks--ext bump stops 1.5"

Fox Racing--all shocks have 1/2" lower mount hole
985-24-008 stock length internal reservoir shock
985-24-057 10" travel external reservoir shock
985-26-057 10" travel external reservoir shock w/ compression adjusted

Bilstein
5125 series
33-065283 8.2" travel shock
33-230450 8.6" travel shock

5165 series external reservoir
25-177480 stock length shock
25-177473 8.8" travel shock

98-04 Rodeo, 02-04 Axiom, 01-03 Rodeo Sport & 98-00 Amigos Rear Shocks ONLY
81-91 Trooper rear shocks
92-97 Rodeo rear shocks
Any shock listed above for 81-91 Trooper or 92-97 Rodeo provided you have driver side bent trailing link to clear gas tank.
 
See less See more
#27 ·
If you used different shock towers then yes you could mount a reservoir style shock up front. You have to figure out the amount of shaft travel then select the appropriate shock. I'm not sure I listed a reservoir shock that would work up front though.
 
#28 ·
I see. Then to save me the trouble of pulling shocks and measuring do you happened to know the fully extended/compressed lengths of the front and rear shocks for the 2002 trooper?

Also, am I correct in believing that the shock isn't the down travel limit on the front as it is on other IFS front ends? Its actually that bump stop on the underside of the upper control arm right?
 
#29 ·
Troopers from 92-02 share the same rear shocks. Extended length 19.25" compressed 12.36". OE replacement shocks tend to be close to those number.

The shock is the limit in stock form. There's also a metal stop with a rubber pad. So at some point you need to modify the down stop to increase travel. After that the ball joint is the limit then the CV axle runs out of travel and finally the steering joint. Basically if you really want to maximize travel you need to extend the control arm. Gains on stock arms are around an inch.
 
#30 ·
Great info.

At this point I've done a ball joint flip (old ones were bad when i bought it) but nothing else. So if i plan on cranking up the front and replacing springs in the rear for about 2" each then I should be looking for shocks ~1" longer than stock?

I'm thinking i can use something like (http://www.quadratec.com/products/16030 ... Anp48P8HAQ) this to get away from the stem mount and open up more shock options for the front.
 
#31 ·
Those adapters won't work. They will force you to use a shorter then stock shock which will limit your options.
 
#32 ·
nasty610,

What about those adapters on the rear with a stock length shock and 2.5" lift springs? I had purchased a set of Koni heavy track shocks for a 96 trooper to replace my Axiom electric controlled shocks, when they arrived they had the loop style mount (I guess some troopers had that style mount rather than the stud mount?) I assumed the extra inch of length would work with my OME 913 springs.
 
#33 ·
1g Troopers came with a upper post mount in the rear. The 1g Rodeos and Amigos used the exact same shock. 92-02 Troopers used thru bolt mounts upper and lower. Honestly unless you're going for max flex a stock length shock will work fine in the rear at that lift. I used stock replacement on mine and had zero problems.
 
#34 ·
Do you know what the extended and compressed lengths are for the 2002 Trooper front shocks?
 
#35 ·
Front shocks are exactly the same regardless of model or year. I don't know the measurement off hand but I do know Isuzu spec'd a longer travel front shock then just about any manufacturer. I'd suggest getting on Rock Auto and looking at the specs for OE replacement shocks. They will be close enough to get you started.
 
#38 ·
92 rodeo xs here. Doing add a leaf in the rear and 6.5 shackels. wanting to get rancho 9000 and want to male sure i get the right ones. So will all these shocks listed work with my lift?

82-91 Trooper & 92-97 Rodeo Rear ONLY
80-89 Toyota Land Cruiser Front shocks
91-98 Toyota Land Cruiser rear shocks--ext bump stops 1"
1/98-06 Toyota Land Cruiser Rear shock--ext bump stops .5"
00-06 Toyota Tundra 4wd rear shocks-.5-1"
08-15 Toyota FJ Cruiser rear shocks-ext bump stops 1"
07-16 Toyota Tundra Shocks--ext bump stops 2"
99-06 Mitsubishi Montero rear shocks--ext bump stops 1.5"
 
#39 ·
I don't know. I made the list to show possible shocks to be used. It's up to the end user to do the math and figure out which shock they need for their setup.
 
#40 ·
I'll copy and paste this from one of my threads. These shocks have been on the truck for around 500 miles or so and are absolutely perfect. 2001 Rodeo.

Pro Comp 915510 ES9000's will work up front with a little help. You will need to cut about 1/4" of the lower rubber and sleeves off because they are just a touch too wide for the factory mounts. I used an angle grinder. You do not have to cut any of the shock body, only the grommet and sleeve. The OEM Isuzu shocks are about 9 1/2" compressed, 14 3/4" extended. The 915510's are 10.02" and 15.69". There are no clearance issues.

Pro Comp 921515's will work on the rear. The factory rears are about 12" collapsed and 19" extended. The 921515's are 13.06" and 21.75". These will work but you will have to make a few changes. First, you'll need to re-use one of your OEM upper mount bushings. It is about half as thick as the ones Pro Comp provides. If you don't, you won't have any threads showing on the shock stud. Put the OEM bushing on the shock stud, install the shock, then use the Pro Comp bushing and washer on the top and tighten down the nut. On the lower mount you'll need to add about 1/4" washer before you install the shock. It doesn't rub without it, but its too close for comfort. The 921515 comes with t-bar mounts. You'll have to remove these. I just used a C-clamp and pair of pliers. The front shocks came with two sizes of sleeves. You'll use the small sleeve for the fronts. The rears won't come with any sleeves. The big sleeves that the front comes with is just a little too small for the rear shock mount. I slid a tapered punch in it and opened it up just a little. I pressed it into the shock's bushing after I opened it enough to slide over the mount.

These have fairly substantially bigger bores and rods. The ride is great, the preload on the rears will pick the truck up some. It takes about 100lbs to compress the rears. I got 265-70-16 Terra Grapplers on it with no rubbing at any point lock to lock. The torsion bars were tightened about 3 turns or so and I removed the mud flaps. No other mods to the ride height as of yet. It will be getting a set of Trooper rear springs when I swap out the diff with a Trac Loc/disk model in the upcoming weeks and I'll let you know how the clearance is.
 
#41 ·
So 1998+ Rodeo and 1998+ Trooper Front shocks are interchangeable? I checked RockAuto for the compressed & extended shock lengths for both Rodeo's and Troopers of this generation and they seem around 0.5" to 0.75" different. Keep in mind when I check the specs for different brand shocks specified for just the Rodeo there is around 0.5" differences between compressed & extended lengths for some. So, I am not sure what the tolerances are from the factory, but I would guess this around 0.5" extra in extended length or 0.5" less in compressed length is fine for the vehicle.

But, I noticed Rockauto lists different part numbers for the same brand and model of shocks: KYB, Bilstein, Monroe, etc, between the Rodeo and Trooper. So if they are truly interchangeable, why the differing part numbers?
 
#42 ·
I'm confirming the 00-06 Toyota Tundra 4wd rear shocks does indeed fit the 2nd gen Rodeo/Passports with a 2-2.5" lift. It fit my '98 Passport with the lower shock mount bushing changed. I'm posting here in case anyone searches for options in the future. I can't never find what the 2nd gen Rodeo guys run when they lift their rigs.

2-2.5" lift. 2nd gen Rodeo/Passports.

Front lift: Torsion cranked (Turn the big torsion key bolt clockwise - hint measure the stud sticking out on top)
Front shocks: Keep stock replacement shocks as OP stated. I run Bilstein F 24-185363

Rear lift: Moog CC247 Cheap replacement spring that is roughly 2.5" longer than stock. Almost same spring rate.
Rear shocks: Bilstein #24-185394. 2-2.5" longer than OE shocks. Press out lower bushing with a ball joint press. Replaced bushing with Energy Suspension 9.8108G 3/4" bushing. Also add Dexter K7129100 14mm ID bushing sleeve. It will fit into the factory axle mounted stud. The sleeve is 44.45mm long, trim it down to 40mm and it will be flushed with the smooth section of the axle mounted stud. The top stem bushings that comes with the shock are too small and cannot be use. Keep the thick OE top bushings.
 
#43 ·
So I've ran into a couple issues. 96 passport 4wd.

Rear mount stud is not 14mm. I've got 16mm on my calipers. The threads are about 12mm.

I've got Toyota shocks and the bushing id is 12mm. So if I drill the bushing out it will be destroyed but might fit loosely.

Even rock auto lists the lower eyes on some rear Isuzu listed shocks to be 12mm. I don't get it.

Anyone ran into this? Why is my mount 16mm+? See pics. Thanks dudes.
 

Attachments

#46 ·
I just installed the KYB Gas-a-just rear shocks from a 2005 RWD Ranger in the rear of my 97 Trooper. The bushings weren't right so I replaced both bushings with Energy suspension 3/4" shock bushings. For the bottom, that is all that is needed because the mount is 19mm (3/4"). For the top, i made a bushing sleeve from 3/4" DOM and drilled it out to fit the 14mm (9/16") bolt. I haven't driven it yet, but the install was straight forward and should give about 2.25" more wheel travel from the 1.61" extra stroke.


 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top