A lifted red facelifted first-generation Isuzu Trooper four-door with a roof rack, winch bumper and mud tires on a snowy forest trail
ISUZU TROOPER · UBS · 1981–1991

Isuzu Trooper (first generation)

UBSTROOPER II (US)BIGHORN (JAPAN)JACKAROO (AUS/NZ)PART-TIME 4WDIFS · TORSION BARS

“A pickup truck wearing a shoebox, and that's a compliment. The first Trooper is narrow, tall, slow and gloriously honest, with more cargo room than it has any right to. Buy the rust-free one, not the shiny one.”

PART 01

Overview

Where it came from, why it matters, and how it changed year to year.

The story

In September 1981 Isuzu announced a compact four-wheel-drive wagon called the Rodeo Bighorn. Underneath it was the company's own pickup, sold in America as the Isuzu P'UP and Chevy LUV. Car and Driver reckoned that almost everything under the squarish steel skin, from the chassis to the driveline, was identical or very similar to the four-wheel-drive pickup. On top sat a body drawn with a set square: flat glass, flat sides and a roof you could land a helicopter on. It would be sold under more names than almost any SUV in history, and every one of them was a box.

THE TROOPER II ARRIVES

America got it for 1984 as the Trooper II, a two-door imported as a truck. Isuzu chose to pay the 25 percent duty on light trucks rather than squeeze it into Japan's car import quotas, which is why the rear seat was a $300 option. The 'II' marked that truck version; a passenger-car 'Trooper I' was promised and never came. Car and Driver's May 1984 test car had the 1.95-liter four with 82 hp, a four-speed manual and a 13.2-gallon tank. The magazine called the power modest and the ride about as plush as a 4x4 got, and estimated the base price at well under $9,000.

Isuzu's own 1985 brochure shows how quickly the truck grew. That year brought a four-door body, a 2.3-liter gas four, a 2.2-liter turbo-diesel (not sold in California), a five-speed, auto-locking front hubs, three skid plates and a 21.9-gallon tank. The brochure also boasted that the Trooper II had been named 4-Wheel & Off-Road magazine's 1985 '4x4 of the Year', ahead of rivals including the Jeep Cherokee and Toyota 4Runner.

GROWING UP, 1987–1991

For 1987 the Trooper II got flush rectangular headlights, a bold new grille, a wider track and bigger P235/75R15 tires, and the four-door could now be had as a plusher LS. The brochure quoted 96 hp and 123 lb-ft from the 2.3-liter four, and the same brochure shows a Trooper II racing in the Baja 1000's Class 14 in November 1986. For 1988 the 2.6-liter 4ZE1 with fuel injection and 120 hp arrived, and for 1989 Isuzu added an optional 2.8-liter General Motors V6, the pushrod engine from the Chevrolet S-10, until its own V6 was ready.

Late trucks could also be had with a four-speed automatic: Wikipedia says four-cylinder trucks used an Aisin A340H and V6 trucks a GM 4L30E. The basic hardware never changed much. An independent front end on torsion bars, a live rear axle on leaf springs, part-time four-wheel drive and a two-speed transfer case made it more capable than its skinny tires and narrow track suggested. In 1989 only, Isuzu sent America the short-wheelbase, two-door Trooper RS (see the sidebar).

ONE BOX, MANY BADGES

Outside the US the truck was everywhere, under different names. Australians and New Zealanders bought it as the Holden Jackaroo, named after the word for a young man working on a sheep or cattle station. Indonesia and South America knew it as the Chevrolet Trooper, Venezuela built it locally as the Caribe 442, and in Japan it was the Isuzu Bighorn. From November 1988 Subaru sold a Bighorn of its own, only with Irmscher trim and the 2.8-liter turbo-diesel. Isuzu also offered a limited run of 100 Bighorn Irmscher R models, with Recaro seats and graphics but no extra power.

The strangest relative came from Korea. In November 1988 SsangYong began licensed production of the Trooper under its own bodywork as the Korando Family, first with the Trooper's 2.2-liter diesel and later with Peugeot and Mercedes-Benz diesels. Rival boxes of the era included the first Mitsubishi Pajero and Toyota's 4Runner, while Curbside Classic's owner story compares the Trooper's shape to the Range Rover at less than half the price.

HOW IT ENDED

Isuzu replaced it with a bigger, more luxurious second-generation Trooper in December 1991. The old shape went out on a high in Australia, where a short-wheelbase Holden Jackaroo won the Marathon class of the 1989 Australian Safari in Peter Lockhart's hands, and it lived on for years in Korea as the Korando Family.

Today the first Trooper is a cult truck with modest prices: Bring a Trailer sales from 2024 to 2026 run from $3,500 for a 2.6-powered 1986 project to $14,250 for a 1986 two-door LS five-speed, with a Japanese Bighorn Irmscher at $25,000. Owners love the space and the visibility. They also warn about rusted rear-door hinges, cracked cylinder heads and failed head gaskets on the fours, and wheel studs that strip at the first impact gun. Parts support has thinned, so many owners rely on the Planet Isuzoo community for help.

SIDEBAR · THE SHORT ONE

Trooper RS and the Safari-winning Jackaroo

For 1989 only, Isuzu imported a short-wheelbase two-door to the US as the Trooper RS. Wikipedia lists the wheelbase at about 90 inches, against 104 for the regular truck. Every RS had the fuel-injected 2.6-liter four, 4.77:1 axle gears and 15 x 7-inch 'snowflake' alloys, with a choice of manual or automatic.

Australia had the same short body as the Jackaroo SWB, and one of them gave the box its best sporting moment of the decade: Peter Lockhart won the Marathon class of the 1989 Australian Safari in one.

Year by year

What changed, model year by model year. Sweet spot Beware

  1. 1981September: Isuzu announces the Rodeo Bighorn in Japan, a compact 4WD wagon on its pickup chassis
  2. 1984US launch as the Trooper II two-door: 1.95 L gas four (82 hp) or 2.2 L diesel, four-speed manual, rear seat optional
  3. 1985Four-door body, 2.3 L gas four, 2.2 L turbo-diesel (not in California), five-speed, auto-locking hubs and a 21.9 gal tank
  4. 1987Facelift with flush rectangular headlights and a new grille, wider track, P235/75R15 tires and a four-door LS
  5. 1988Fuel-injected 2.6 L 4ZE1 with 120 hp arrivesSweet spot
  6. 1989Optional 2.8 L GM V6; one-year-only short-wheelbase Trooper RS two-doorSweet spot
  7. 1990–1991Recalls for the oil-cooler hose (90V166) and automatic transmission overfill (90V167); NHTSA's owner complaints include under-hood fires and stripped wheel studs
  8. 1991December: replaced by the second-generation Trooper
PART 02

Specs & capability

How it’s built, what it can do, and what fits under it.

How it’s built

The first Trooper is a pickup-derived ladder frame with an independent, torsion-bar front end and a leaf-sprung live rear axle. Four-wheel drive is part-time, through a two-speed transfer case and either auto-locking or manual front hubs. Engines started as small Isuzu fours and finished with a GM V6, and the wheels bolt on with six studs on a 139.7 mm circle.

CHASSISLadder frame from the Isuzu P'UP / Faster 4x4 pickupWheelbase 2,650 mm (104.3 in) for the long three-door and five-door; 2,300 mm for the short-wheelbase body.
FRONT SUSPENSIONIndependent double wishbone on torsion barsIsuzu's 1987 brochure quotes a front stabilizer bar over an inch thick.
REAR SUSPENSIONLive axle on two-stage semi-elliptic leaf springsFront disc and rear drum brakes on 1987 US trucks.
4WD SYSTEMPart-time, two-speed transfer caseSelected with a separate lever. Isuzu auto-locking hubs or Aisin manual hubs; with the hubs engaged you can shift between 2WD and 4WD high without stopping.
ENGINES (US)1.95 L, 2.3 L and 2.6 L fours; 2.8 L GM V6 (1989–91)Plus a 2.2 L diesel and turbo-diesel in the mid-1980s. Overseas: 2.8 L 4JB1 diesels.
PROTECTIONThree skid platesIsuzu's brochures list plates for the radiator, the transfer case and the fuel tank.

Variants & engines

YEARSPLATFORMENGINEOUTPUTWORTH KNOWING
1984 (US)Trooper II 2-doorG200Z 1.95 L SOHC I4 / C223 2.2 L diesel I482 hp / 101 lb-ft; diesel 62 hp / 96 lb-ftFour-speed manual, 13.2 gal tank. Imported as a truck; the rear seat was a $300 option.
1985–1987 (US)Trooper II 2-door and 4-door4ZD1 2.3 L SOHC I4 / C223T 2.2 L turbo-diesel96 hp / 123 lb-ft; turbo-diesel 80 hp / 125 lb-ft (1987 brochure)Five-speed, auto hubs, 21.9 gal tank. Turbo-diesel not sold in California. Facelift with rectangular lamps for 1987.
1988–1991 (US)Trooper II / Trooper4ZE1 2.6 L SOHC I4, fuel-injected120 hpFive-speed manual or Aisin A340H four-speed automatic.
1989–1991 (US)TrooperGM LL2 2.8 L OHV V6122 hp / 204 N·mBorrowed from the Chevrolet S-10; automatic trucks used the GM 4L30E.
1989 (US)Trooper RS (short wheelbase)4ZE1 2.6 L I4120 hpAbout 90 in wheelbase, 4.77:1 gears, 15 x 7 in 'snowflake' alloys. One year only.
Late 1980s (export)UBS55 Bighorn / Jackaroo / Trooper4JB1 2.8 L diesel and 4JB1-T turbo-diesel95 PS (turbo), up to 115 PS intercooledNever sold new in the US.

Capability numbers

Payload1,374 lb (2-door) / 1,319 lb (4-door)1987 gas trucks, Isuzu brochure; 1,222 lb for the 1984 two-door tested by Car and Driver
Fuel tank21.9 US gal (83 L)From 1985; 13.2 gal on the 1984 two-door
Ground clearance8.3 in (211 mm)Minimum, at the rear differential (Isuzu brochures)
Fuel economyEPA 21 city / 27 hwy (1984 1.95); 17 / 20 (1987 2.3 five-speed)Car and Driver averaged 21 mpg in 1984
Curb weight3,366 lb (2-door) / 3,421 lb (4-door)1987 gas trucks
Turning circle38.8 ft (11.8 m) curb to curb1987
Cargo volume79.0 cu ft without the rear seat45.5 cu ft with the seat up

Wheels & tires

FACTORY TIRES
P235/75R15 on 6.0 x 15 (Deluxe) or 6.5 x 15 (LS) wheels, 1987 US15 x 7 alloy 'snowflake' wheels on the 1989 Trooper RS
Bolt pattern6x139.7 (6x5.5")
Offset+3 mm (stock 15 x 6.5, per ThreePiece.us)
Center bore100 mm
Lug threadM12x1.5

Forum consensus, not a guarantee: wheel offset, tire brand and suspension wear all change clearance. Confirm before you buy.

Production & special editions

Built from September 1981 to 1991 in Japan, and assembled or licence-built in several other countries.

ProductionSeptember 1981 – 1991 (Japan)
AssemblyFujisawa, Japan; also Colombia (GM Colmotores), Indonesia (Garmak), Philippines (Pilipinas GM), Venezuela (Mack de Venezuela)
Licence-builtSsangYong Korando Family, South Korea, November 1988 – 1996
US model years1984–1991
Bighorn Irmscher RJapan, late 1980sLimited run of 100 with Irmscher cosmetic and interior upgrades
Subaru BighornNovember 1988 – February 1992Irmscher trim only, 2.8 L turbo-diesel
Trooper RS1989 (US)Short-wheelbase two-door, 2.6 L, 4.77 gears, snowflake alloys
PART 03

Buying one

What to pay, what to check, and how to tell a good one from a clone.

What they cost

First-generation Troopers are still cheap, but tidy, rust-free two-doors and rare diesels are starting to pull ahead.

Project / needs work$3.5k–5.5k
Driver$7k–9.5k
Excellent / rare spec$14k–25k

Based on 13 Bring a Trailer first-generation sales, October 2024 – July 2026: $3,500 (a 2.6-powered 1986) to $14,250 (a 1986 Trooper II LS two-door five-speed). A 1991 Bighorn Irmscher turbo-diesel sold for $25,000. Prices move; checked October 2026. See live listings below.

What to check before you buy

  1. 01
    Rust first, everything else secondCheck the rear cargo doors, their hinges and pins, the floors and the sills. Isuzu recalled 1984–87 trucks (92V093) because salt-belt corrosion in the rear-door hinges could let the doors close in a false latch, and a Curbside Classic reader summed up the rest: once the rear doors started to rust, it was game over.
  2. 02
    Look at every wheel studStripped or snapped wheel studs and galled lug nuts are among the most common owner complaints logged with NHTSA for 1988–91 Troopers, and Curbside Classic's owner broke them too. Make sure all 24 studs are present and the nuts thread on by hand.
  3. 03
    Ask about the head and head gasketNHTSA's complaint files for 1988 and 1989 Troopers include several cracked cylinder heads and repeated head-gasket failures, and a Curbside Classic reader lost his truck to 'the head gasket issue'. Look for a history of overheating, coolant in the oil and a radiator that hasn't been neglected.
  4. 04
    Check that the recall work was done1990–91 trucks were recalled for an oil-cooler hose that could touch the exhaust manifold and melt (90V166), and for automatic transmissions that could spill overfilled fluid onto the exhaust (90V167). On 1987–88 trucks (89V001), a heater bolt could rub through a fuel pipe. NHTSA's 1990–91 complaint files also include several under-hood fires.
  5. 05
    Engage the hubs and the low rangePut it in 4WD high and low on loose ground. Auto-locking hubs should lock and unlock reliably, and the transfer case should shift without a fight. Many owners swap tired auto hubs for manual ones.
  6. 06
    Know which engine you're gettingEarly 1.95s and 2.3s are slow; the injected 2.6-liter four (1988–91) and the 2.8-liter GM V6 (1989–91) are the ones to want. US turbo-diesels from the mid-1980s are rare and were never sold in California.
  7. 07
    Drive the automatic hardA Curbside Classic reader's automatic failed at about 175,000 miles, and NHTSA's 1990–91 complaint files include several slipping, leaking or failed transmissions. A five-speed is the simpler buy.
  8. 08
    Ask for the timing-belt receiptThe Isuzu four-cylinder petrol engines use a timing belt (the 2.3 switched from a chain to a Kevlar belt), so a truck with no record needs one before it goes anywhere remote.

Spotting the real thing

First-generation Troopers were sold under many names and with engines the US never got, so check what you're looking at, especially with right-hand-drive Japanese or Australian imports.

  1. ID
    Chassis codes by engineWikipedia lists UBS13 (1.95 L G200Z), UBS16 (2.3 L 4ZD1), UBS17 (2.6 L 4ZE1), UBS52 (2.2 L C223 / C223T diesel) and UBS55 (2.8 L 4JB1 diesel). The US V6 trucks use GM's 2.8 L pushrod engine.
  2. ID
    Facelift1984–86 trucks have the original front end; from 1987 the Trooper II has flush rectangular headlights and a new grille.
  3. ID
    Trooper RSThe 1989-only US short-wheelbase two-door has a wheelbase of about 90 inches instead of 104, a 2.6 L four, 4.77:1 gears and 15 x 7 'snowflake' alloys.
  4. ID
    Re-badgesHolden Jackaroo (Australia and New Zealand), Isuzu Bighorn and Subaru Bighorn (Japan), Chevrolet Trooper (Indonesia and South America) and Caribe 442 (Venezuela) are the same truck. SsangYong's Korando Family is licence-built with its own bodywork.
  5. ID
    Bighorn Irmscher RA limited run of 100 Japanese-market Bighorns with Irmscher graphics, a hood scoop, fender flares, Recaro seats and an Irmscher wheel, all cosmetic, with the 2.8 L intercooled turbo-diesel.

Recalls & service bulletins

Open recalls follow the VIN, not the model. Run yours through NHTSA before you buy, and ask the seller for dealer records showing recall work.

Check a VIN at NHTSA ↗
Notable recalls
Rear-door hinge corrosion and false latching ↗1984–1987 · NHTSA 92V093In salt-belt states corrosion in the rear-door hinges, combined with misaligned latches, could let the doors close in a 'false latch' condition.
Heater bolt can rupture the fuel pipe ↗1987–1988 · NHTSA 89V001Too little clearance between a heater mounting bolt and a fuel delivery pipe (and a rear heater hose clip) could rupture the pipe and leak fuel.
Oil-cooler hose can melt on the exhaust manifold ↗1990–1991 · NHTSA 90V166An improperly installed oil-cooler hose could touch the exhaust manifold and melt.
Overfilled automatic transmission can spill fluid on the exhaust ↗1990–1991 · NHTSA 90V167Overfilled ATF could bleed through an air groove onto the exhaust manifold as the oil warmed up.
Reese trailer-hitch receiver weld ↗1986–1991 · NHTSA 93E023Equipment recall by Reese Products: the weld on the hitch receiver could break.

Importing & legality

Every first-generation Bighorn, Jackaroo and export Trooper is now well past 25 years old, so it can be imported to the US under the 25-year exemption from federal safety and emissions standards. That's the route to the 2.8-liter 4JB1 diesels and the Japanese special editions the US never got. Car and Driver reported that the Irmscher R Bighorn sold in 2019 had arrived in the US in 2015.

Federal eligibility doesn't guarantee registration everywhere, and California is the hardest state for imported diesels, so check your state's titling and emissions rules before you buy.

Rules change and vary by state and country. Confirm with your DMV and a licensed importer before you buy.

The one you’ll own someday

For sale now

1984–1991 · USIsuzu Trooper
1984–1991 · USIsuzu Trooper II
PART 04

Owning one

Baseline service, the repairs you’ll actually do, and where the manuals live.

Post-purchase baseline

After you buy it

Treat any first-generation Trooper as unserviced until receipts prove otherwise. These trucks are 35 to 40 years old, so the cheap fluids and rubber parts are what keep the engine and drivetrain alive. Isuzu's factory specs aren't widely published online, so confirm grades and capacities in the owner's or service manual for your engine.

Engine oil & filter[CONFIRM IN MANUAL]Then at the owner's-manual interval

Watch for leaks at the oil-cooler hoses on 1990–91 trucks; recall 90V166 rerouted a hose that could touch the exhaust manifold.

Air filter & fuel filterReplace bothThen inspect at every oil change

Old fuel filters and tired pumps cause many hard-start complaints on old trucks.

IgnitionPlugs, wires, distributor cap and rotor (2.6)Then per the manual

The 1988–91 2.6-liter uses a distributor, so the cap and rotor are part of a tune-up.

Timing belt (four-cylinder petrol)Belt, tensioner, cam and crank sealsNow, if there's no record; then per the manual [CONFIRM IN MANUAL]

The 2.3 and 2.6 Isuzu fours use a belt.

Coolant, hoses and thermostatCoolant type per the manual [CONFIRM IN MANUAL]Flush now

Owners report cracked heads and head gaskets on these engines, so a healthy cooling system is cheap insurance.

Manual transmission oil[CONFIRM IN MANUAL]Drain and refill now

Check the clutch hydraulics while you're under there.

Automatic transmission fluid & filter[CONFIRM IN MANUAL]Pan drop and filter now

Don't overfill. That's what recall 90V167 was about on 1990–91 trucks.

Transfer case[CONFIRM IN MANUAL]Drain and refill now

Shift through 2H, 4H and 4L afterwards to check the linkage.

Front & rear differentialsGear oil per the manual [CONFIRM IN MANUAL]Drain and refill now

Check the pinion seals for leaks.

Front hubs & wheel bearingsClean, inspect, repackNow, then as needed

Water in auto hubs is a common cause of hubs that won't engage.

Brake fluid & hosesFlush; inspect the rubber hosesEvery two years

Front discs and rear drums; check the rear wheel cylinders for leaks.

U-joints & driveshaftsGrease the fittings; check for playAt every oil change

One 1990 owner reported a driveshaft falling while driving; check for play in the joints and loose bolts.

Wheel studs & lug nutsInspect every stud and nutEvery tire rotation

Hand-start every nut and torque to spec; never let a shop hammer them on with an impact gun.

For the hands-on owner

Common repairs

The jobs owners actually end up doing, rated for a competent home mechanic with a decent tool kit. Always confirm torque figures, fluids and procedures against the factory service manual for your VIN, and work safely — support the truck on stands, never just a jack. You do this work at your own risk; see the disclaimer. Some parts links are affiliate links.

Replace stripped or broken wheel studs
DIFFICULTY · 2 / 5TIME · An afternoonSHOP COST · Parts plus labor
SYMPTOMSLug nuts that won't thread on, studs that snap when a tire shop uses an impact gun, or a wheel that loosens. Owners have reported all three to NHTSA.
THE FIXSupport the truck safely and pull the wheel. On the front, remove the caliper and rotor to reach the back of the hub; on the rear, pull the drum. Drive out the damaged stud, clean the hub, then draw the new stud in with a stack of washers and a lug nut, or press it in, until the head seats fully. Fit new lug nuts with any damaged studs, start every nut by hand and torque them to the factory spec in a star pattern. Tell your tire shop to do the same.
TOOLS & PARTSHammer and punch or a stud press · washers · torque wrench · factory torque spec [CONFIRM IN MANUAL].
Timing belt on the 2.3 and 2.6 fours
DIFFICULTY · 3 / 5TIME · A daySHOP COST · Parts plus labor
SYMPTOMSNone until it fails. A truck without a belt receipt is due.
THE FIXDisconnect the battery, drain the coolant and remove the fan, drive belts and crankshaft pulley, then the timing covers. Set the engine to top dead center and line up the cam and crank timing marks before you loosen anything. Fit the new belt and tensioner, check the marks again after turning the engine over twice by hand, and replace the cam and crank seals if they're weeping. Many owners do the water pump at the same time.
TOOLS & PARTSSocket set · crank-pulley holding tool · torque wrench · factory service manual.
Cooling-system refresh to protect the head
DIFFICULTY · 2 / 5TIME · A morningSHOP COST · Parts plus labor
SYMPTOMSCreeping temperature, steam, coolant loss or a sweet smell. NHTSA complaint files describe cracked heads and blown head gaskets on 1988–89 trucks.
THE FIXWith the engine cold, drain the radiator and replace the thermostat, the radiator hoses and the cap. Inspect the radiator for blocked or weeping cores and replace it if in doubt. Refill slowly with the heater on and bleed out air pockets: one 1988 owner blamed air pockets in the head for coolant reaching the cylinders. If the oil looks milky or the cooling system pressurizes quickly, pressure-test it and do a compression or leak-down test before deciding on head work.
TOOLS & PARTSDrain pan · pliers · cooling-system pressure tester · funnel · the coolant type specified for your engine [CONFIRM IN MANUAL].
Service or replace the front locking hubs
DIFFICULTY · 2 / 5TIME · A couple of hoursSHOP COST · Parts plus labor
SYMPTOMSHubs that won't lock in 4WD, grind or clunk when they engage, or won't release.
THE FIXJack up one front wheel at a time. Remove the hub cover bolts and pull the hub body, then clean out old grease and water, check the internals for wear and broken parts and regrease lightly. While it's open, check the wheel-bearing preload and the axle shaft splines. If an auto hub is worn out, many owners fit a pair of manual hubs. Test 4WD high and low on loose ground afterwards.
TOOLS & PARTSHex keys or sockets · snap-ring pliers · grease · factory manual for bearing preload.
Front CV boots and axles
DIFFICULTY · 3 / 5TIME · Half a day per sideSHOP COST · Parts plus labor
SYMPTOMSGrease flung around the inside of the wheel, or a click on full lock under power.
THE FIXSupport the truck, pull the wheel and the hub, disconnect the lower ball joint or knuckle as the manual describes, and slide the axle out of the differential. Either rebuild the joint with a new boot, clamps and grease, or fit a complete replacement axle. Check the differential output seal while the axle is out.
TOOLS & PARTSSocket set · ball-joint separator · boot-clamp pliers · new axle nut.
Free up and protect the rear-door hinges
DIFFICULTY · 2 / 5TIME · An afternoonSHOP COST · Parts plus labor
SYMPTOMSRear doors that sag, bind or don't latch properly. Isuzu's 1992 recall (92V093) covered 1984–87 trucks for exactly this in salt-belt states.
THE FIXSupport each door before you work on it. Soak the hinge pins with penetrating oil, work them free, clean the knuckles and grease them. Treat rust around the hinge mounts and the bottom of the door shells. Then adjust the latch strikers so each door closes positively, with no false latch.
TOOLS & PARTSPenetrating oil · brass drift · grease · rust converter and paint · screwdrivers for striker adjustment.
Automatic transmission service (and the 90V167 recall check)
DIFFICULTY · 2 / 5TIME · An hour or twoSHOP COST · Parts plus labor
SYMPTOMSLate or harsh shifts, a fluid smell or smoke from the exhaust manifold. On 1990–91 automatics, overfilled fluid could escape onto the exhaust (recall 90V167).
THE FIXDrop the pan, replace the filter and gasket, and refill with the specified fluid. Check the level exactly as the manual describes and do not overfill. Confirm with an Isuzu or Chevrolet dealer, or the NHTSA VIN lookup, that the recall work was done.
TOOLS & PARTSDrain pan · socket set · torque wrench · funnel · the specified automatic transmission fluid [CONFIRM IN MANUAL].

Manuals & documentation

Isuzu 1985 Trooper II brochure, USAPeriod brochure scan on the Internet Archive: specifications, equipment and capacities
Isuzu 1987 Trooper II brochure, USASpecifications, tire sizes, weights and payloads for the facelifted truck
NHTSA — recalls by vehicle ↗Official recall data; change the model year in the link
Asked on every forum

Isuzu Trooper (first generation) questions, answered

What's the biggest tire I can fit without a lift?

The factory size from 1987 was P235/75R15, about 29 inches, on 6.0- or 6.5-inch-wide 15-inch wheels. We couldn't verify a first-generation forum consensus for the largest no-lift size, so check the tire-fitment chart and build threads on Planet Isuzoo before you buy, and check the rear-door-mounted spare carrier too. Wheels are 6 x 139.7 mm with a 100 mm center bore and M12 x 1.5 studs.

SOURCE · ISUZU 1987 BROCHURE · THREEPIECE.US
Why is it called the Trooper II?

American Isuzu's product-development manager told Car and Driver in 1984 that 'II' marked the truck version, with the rear seat a $300 option, and 'I' would have been the car version with a standard rear seat. A Trooper I never came. Isuzu imported it as a truck to avoid Japan's car import quotas, and paid the 25 percent truck duty instead.

SOURCE · CAR AND DRIVER
Which engine should I look for?

The 1988–91 2.6-liter 4ZE1 is fuel-injected and makes 120 hp; the optional 1989–91 2.8-liter GM V6 makes 122 hp with more torque. The 1984 1.95-liter made 82 hp and the 1985–87 2.3-liter about 96 hp, so early trucks are slow.

SOURCE · WIKIPEDIA · CAR AND DRIVER · ISUZU BROCHURE
Was there a diesel in the US?

Yes. 1984 trucks could have a 2.2-liter pushrod diesel with 62 hp, and from 1985 Isuzu offered a 2.2-liter turbo-diesel (80 hp in the 1987 brochure), which wasn't sold in California. They're rare now; Bring a Trailer sold a 1986 turbo-diesel five-speed for $8,200 in November 2025.

SOURCE · CAR AND DRIVER · ISUZU BROCHURES · BAT
How does the four-wheel drive work?

It's part-time with a two-speed transfer case on its own lever. From 1985 Isuzu fitted auto-locking front hubs, so once they're engaged you can shift between 2WD and 4WD without stopping. Some trucks had Aisin manual hubs instead. Don't drive in 4WD on dry pavement.

SOURCE · ISUZU BROCHURES · WIKIPEDIA
What fuel economy should I expect?

The 1984 1.95-liter was rated at 21 mpg city and 27 highway, and Car and Driver averaged 21 mpg. Isuzu's 1987 brochure lists 17 city and 20 highway for the 2.3-liter five-speed and claims up to 438 miles per tank of gas.

SOURCE · CAR AND DRIVER · ISUZU 1987 BROCHURE
How much can it carry?

Car and Driver's 1984 two-door had a 1,222 lb payload rating. Isuzu's 1987 brochure lists 1,374 lb (two-door) and 1,319 lb (four-door) for gas trucks, and 79 cubic feet of cargo space with the rear seat removed.

SOURCE · CAR AND DRIVER · ISUZU 1987 BROCHURE
How big is the fuel tank?

The 1984 truck Car and Driver tested had a 13.2-gallon tank. From 1985 Isuzu quoted 21.9 gallons.

SOURCE · CAR AND DRIVER · ISUZU BROCHURES
Is a Holden Jackaroo or Isuzu Bighorn the same truck?

Yes. The Jackaroo (Australia and New Zealand), Bighorn (Japan), Subaru Bighorn, Chevrolet Trooper and Venezuela's Caribe 442 are all the same UBS truck. SsangYong's Korando Family was built under licence with its own bodywork. Imports of Japanese and Australian versions can bring diesel engines the US never got.

SOURCE · WIKIPEDIA
What is one worth?

Bring a Trailer sales from late 2024 to mid-2026 ranged from $3,500 (a 2.6-powered 1986) to $14,250 (a 1986 Trooper II LS two-door five-speed), with most clean drivers between $7,000 and $9,500. A 1991 Bighorn Irmscher turbo-diesel sold for $25,000 in August 2025.

SOURCE · BAT
Can I still get parts?

Service parts such as filters, belts, hubs, CV axles and brake parts are still listed for 1988–91 Troopers at RockAuto. Trim and body parts are harder. Owners on Overland Bound say parts support for Isuzu light trucks has gone downhill, and point to Planet Isuzoo for help.

SOURCE ·
PART 05

Building one

Who makes the good stuff, where owners gather, and who to watch.

Common modifications & who does them

SUSPENSION & BUILD PARTSTorsion bars, leaf springs and shocks are 35 years old. Fresh parts restore ride height before you add bigger tires. An Overland Bound member who has owned a first-generation truck calls Independent4x the most readily available source for many Trooper build parts.
OEM-STYLE REPLACEMENT PARTSBelts, hoses, hubs, CV axles, brakes and ignition parts for the 2.6 and the V6.
WHEELS & TIRESThe 6 x 139.7 mm bolt pattern, with a 100 mm center bore and M12 x 1.5 studs, opens up a wide choice of wheels. Mind the offset: the factory 15 x 6.5 wheel is listed at +3 mm.
COMMUNITY TECHTire-fitment charts, hub swaps, engine swaps and parts sourcing live on the Planet Isuzoo forums.
Resources

Channels, accounts & forums

All Trooper resources →
SourcesIsuzu Motors — Heritage (company history timeline)Wikipedia — Isuzu TrooperWikipedia — List of Isuzu enginesCar and Driver — From the Archive: 1984 Isuzu Trooper II Tested (May 1984)Car and Driver — Irmscher-R Tuned 1989 Isuzu Trooper Bighorn (2019)Isuzu — 1985 Trooper II Two Door & Four Door brochure, USAIsuzu — 1987 Trooper II brochure, USACurbside Classic — My 1988 Isuzu Trooper II: the joys and virtues of a tall and narrow boxBring a Trailer — Isuzu Trooper sold resultsOverland Bound — Isuzu Trooper owners poll (thread)ThreePiece.us — 1987 Isuzu Trooper wheel fitment specsNHTSA — recall 92V093 (1984–87 rear-door hinge corrosion)NHTSA — recall 90V166 (1990–91 oil-cooler hose)NHTSA — recall 90V167 (1990–91 automatic transmission overfill)NHTSA — recall 89V001 (1987–88 heater bolt / fuel pipe)NHTSA — owner complaints, 1988 Isuzu TrooperNHTSA — owner complaints, 1989 Isuzu TrooperNHTSA — owner complaints, 1990 Isuzu TrooperNHTSA — owner complaints, 1991 Isuzu TrooperRockAuto — Isuzu Trooper parts catalogWikipedia — Isuzu TrooperIsuzu Motors — Heritage (company history timeline)Car and Driver — From the Archive: 1984 Isuzu Trooper II Tested (May 1984)Car and Driver — Irmscher-R Tuned 1989 Isuzu Trooper Bighorn (2019)Isuzu — 1985 Trooper II Two Door & Four Door brochure, USAIsuzu — 1987 Trooper II brochure, USABring a Trailer — Isuzu Trooper sold resultsThreePiece.us — 1987 Isuzu Trooper wheel fitment specsNHTSA — recalls, 1986 Isuzu TrooperNHTSA — recalls, 1987 Isuzu TrooperNHTSA — recalls, 1990 Isuzu TrooperNHTSA — owner complaints, 1990 Isuzu TrooperNHTSA — owner complaints, 1991 Isuzu Trooper