October 21, 2026 Farhad Musazada

How to Use a Kei Truck's 4x4: Hi-Lo, Diff Lock and Extra Low

By Farhad Musazada, owner of Skyline Kei Trucks. Last updated: October 21, 2026. Based on Honda, Suzuki, Subaru and Daihatsu releases, catalogs and owner's-manual guidance for the Acty, Carry, Sambar, Jimny and Hijet; manufacturer pages and catalogs verified October 2026; ratios are the makers' published figures (sources at the end). General information; follow the owner's manual for your specific truck.

Key facts

Three kinds of 4x4: Hijet, Carry, Minicab, Jimny and manual Sambar 4x4s are part-time: you switch the front axle in and out. The Honda Acty and the automatic Sambar need no action at all.
The dry-pavement rule: Part-time 4WD has no center differential. Use it on dirt, mud, grass, gravel, sand or snow, and go back to 2WD before you reach pavement. Suzuki's guidance: 4WD on dry paved roads puts a heavy load on the drivetrain.
Low range is for crawling: Stop before shifting into low range or out of it. The Jimny JB23's transfer is 2.643:1 in low against 1.320:1 in high; the 1991 Carry's is 1.900 against 1.000. Low range multiplies torque; it adds no grip.
Extra-low gears: Some trucks put a crawler gear in the gearbox instead: EL on manual Carry (6.264:1 in 1991) and Sambar 4x4s, and UL 7.800 / UR 7.588 on the Acty Attack, against 4.545 for first.
Diff lock: on to get out, off to turn: Only certain versions have one: the Acty Attack (rear), the 1999–2001 Carry Nouhan (switch) and some Hijet farm trucks. Lock it when one wheel spins, crawl out straight, and switch it off before you steer on firm ground.

Which 4x4 system does your truck have?

Every kei truck starts out rear-wheel drive. The 4x4 versions add a driven front axle, connected in one of three ways: part-time (you switch it in and out), full-time (always on, through a viscous coupling) or Honda's real-time system (no lever at all). If you haven't picked a model yet, start with our Hijet vs. Carry vs. Acty vs. Sambar comparison. The table covers trucks old enough to import in 2026 (2001 builds and earlier); the model code is on every listing.

Truck and codes	4x4 type	You engage it with	Low range or crawler gear	Diff lock
Daihatsu Hijet S83P, S110P, S210P (1990–2001)	Part-time	Control in the cab	High/low on some farm versions	Some farm versions (S210P farm pack)
Suzuki Carry DD51T (1991–98), DB52T (1999–2001)	Part-time	Transfer lever on manuals	Two-speed high/low; some 1991–98 trucks have EL instead	Switch-operated, 1999–2001 Nouhan (farm) version
Honda Acty HA4 (1990–99), HA7 (1999–2001)	Real-time, viscous coupling	Nothing; it engages itself	Attack version: UL and UR gears	Attack version: rear lock
Subaru Sambar KS4 (1990–98), TT2 (1999–2001)	Manual: part-time. Automatic: full-time viscous	Manual: switch (on the shift knob on the TT2). Automatic: nothing	EL gear on manuals	—
Mitsubishi Minicab U42T (1991–98), U62T (1999–2001)	Part-time	Switch (on the shift lever on the U62T)	Separate high/low lever on 1999-on manuals	Optional limited-slip, not a locker
Suzuki Jimny JA11, JA12, JA22, JB23 (1990–2001)	Part-time	Transfer lever: 2H, 4H, 4L (push-button on later JB23s)	Two-speed transfer; JB23: 1.320 high, 2.643 low	—

A dash means the catalogs we read list no lock. For a particular truck, call or text us with the stock number, or come to the lot and work the controls yourself; every truck is sold as is by Wideway Motors LLC, so see how it drives before you buy.

How do you engage 4WD?

On any part-time truck: slow to a walking pace or stop, straighten the wheels, lift off the gas, then select 4WD. Go back to 2WD the same way, before the tires touch pavement.

Levers

Manual Carry 4x4s have a second, shorter lever next to the gear lever; Suzuki's 1999 catalog lists a two-speed high/low transfer, so it gives you 2WD, 4WD high and 4WD low. The Jimny uses the same layout, marked 2H, 4H and 4L. Suzuki's JB23 catalog allows the shift from 2WD to 4H on the move at up to 100 km/h (62 mph) in a straight line, but 4H to 4L only with the truck stopped: clutch fully in on a manual, selector in N on an automatic. If the lever resists, don't force it; roll a few feet and try again. The JB23's air-locking hubs engage the front wheels on their own in 4H; if your Jimny has manual free-wheeling hubs instead, turn both to LOCK first and back to FREE afterward.

Switches

Minicab 4x4s use a switch, on the shift lever on the 1999–2001 U62T, whose Easy Select system can go into 4WD high on the move at up to 80 km/h (50 mph); manuals add a separate low-range lever. Manual Sambar 4x4s have the 4WD switch on top of the shift knob. Hijet 4x4s are switched from the cab too. Daihatsu's current farm trucks add a Hi-Lo lever and a Super Diff Lock switch, and the 1999–2001 S210P farm pack offered similar extras, so read the labels on the truck.

Nothing to do: the Acty

The Acty 4x4 has no lever and no switch. Honda's May 1988 release describes a viscous coupling that sends drive to the front wheels on its own as the surface changes (uphill, downhill, snow, mud), and the May 1999 release says the HA7's system switches automatically to suit road conditions. Automatic Sambar 4x4s work the same way. Drive them like any other truck, on any surface.

When do you use low range or the extra-low gear?

Low range doesn't add grip. It multiplies torque and slows the truck so you can crawl without slipping the clutch. Suzuki's JB23 catalog lists the transfer at 1.320:1 in high and 2.643:1 in low; the September 1991 Carry catalog lists 1.000 high and 1.900 low. Use it for steep ranch tracks, deep mud or sand at walking pace, backing a loaded bed down a slope and creeping across a plowed field. Shift into low only when stopped, and back to high as soon as the ground eases.

Several trucks put a crawler gear inside the gearbox instead. Suzuki's 1991 Carry catalog lists an EL + 5-speed manual with an extra-low ratio of 6.264:1. Subaru's catalog for the TT2 Sambar says the EL gear helps with starting on rough ground. The Acty Attack goes furthest: Honda's spec sheet for the HA7 Attack lists an ultra-low gear of 7.800:1 and an ultra-reverse of 7.588:1, against 4.545 for first and 4.300 for normal reverse. You select these with the main gear lever, so the drill is the same: stop, select, crawl, then shift up to first once you're moving. Honda built UL and UR in 1988 for paddy-field paths and mud; UR backs a loaded bed up a bank just as slowly.

What does the diff lock do, and when should it be off?

A normal differential sends power to the wheel with the least grip: one rear wheel in a rut spins, the other does nothing. A diff lock ties the two rear wheels together so the wheel with grip pulls you out. Honda's 1988 release describes the Attack's lock as directly coupling the rear driveshafts, and the 1999 release calls the HA7 Attack a 4WD with a diff lock for farm work. The 1999–2001 Carry Nouhan has a switch-operated lock, and some Hijet farm trucks have one.

Use it stopped or at a crawl, pointing straight ahead, when a wheel is already spinning. Switch it off the moment you're out, and always before you turn on firm ground: with both rear wheels locked the truck wants to go straight, the inside wheel scrubs and the lock takes the strain. Never lock it at road speed or on pavement. The Minicab's optional limited-slip differential is different: it works on its own, with nothing to switch.

Driving on pavement, mud, sand and slopes

Pavement. Two-wheel drive, every time. In a part-time truck the axles are locked together, but in a corner the front wheels travel farther than the rear. On loose ground the tires slip a little and the difference disappears; on pavement it can't, so the driveline winds up and the steering goes heavy. Suzuki's guidance for the Jimny: don't use 4WD on dry paved roads, because the drivetrain can't absorb the difference in rotation between front and rear tires. Treat wet pavement the same way, and switch back to 2WD at the gate, not at the highway.

Mud and Texas clay. Much of Texas sits on expansive black clay. Houston Black, the state soil, covers about 1.5 million acres from north of Dallas to San Antonio, and the Texas Water Development Board describes clay that cracks open when dry, takes water fast through the cracks, then lets it in very slowly once wet. That is why a pasture stays slick for days after rain; wet gumbo packs the tread solid. Select 4H before the soft stretch, not after you're stuck; keep a steady throttle and let the truck walk through. If you stop, don't spin the tires fast (Daihatsu's Hijet manual gives that warning); spinning digs the truck in. Stuck anyway: lock the diff if you have one, select low, and rock gently between first and reverse.

Sand and slopes. 4H before the sand, keep rolling, steer gently, stop only on firm ground. On a steep slope: low range, straight up and straight down, the engine holding the truck on the descent, and no turning across the slope with a load in the bed.

Towing a stuck truck out. Strap to a frame tow hook, never the bumper; keep everyone clear of the strap; stuck truck in neutral, wheels straight; pull at walking pace in a straight line. A kei truck is light, so a steady pull from a pickup or tractor does it. A yank breaks things.

Simple upkeep

A part-time system has oil in the gearbox, the transfer case and both differentials. Change those oils on the schedule in the truck's maintenance booklet, which Daihatsu prints separately from the owner's manual, with the type it specifies, and sooner after deep water. Use the system: select 4WD on dirt for a few minutes every month so the hubs, shift forks and seals keep moving. Keep all four tires the same size and at similar wear; mismatched tires make the axles fight each other even on loose ground. Hose the clay off the underside after a muddy day so the levers, hubs and breathers stay free.

Frequently asked questions

Can I drive a kei truck in 4WD on the highway?

Not a part-time truck: keep a Hijet, Carry, Minicab, Jimny or manual Sambar in 2WD on pavement, wet or dry. An Acty 4x4 or an automatic Sambar 4x4 has nothing to switch, so drive it normally everywhere. For which trucks came with 4x4, see the 4x4 entry in our FAQ.

Can I shift into 4WD while moving?

Sometimes. Suzuki's JB23 Jimny catalog allows 2WD to 4H at up to 100 km/h (62 mph) in a straight line; Mitsubishi's Easy Select on the 1999–2001 Minicab allows 4WD high at up to 80 km/h (50 mph). Low range is the same on every truck: stop first. On an older truck without that guidance, slow to a walking pace, straighten the wheels, then shift.

Does my kei truck have a diff lock?

Only if it is one of the versions that came with one: the Acty Attack, the 1999–2001 Carry Nouhan, or a Hijet farm truck with the option. Look for a switch or lever labeled DIFF LOCK or デフロック, usually with an indicator lamp. If a listing doesn't mention a lock, assume there isn't one.

What does real-time 4WD mean on a Honda Acty?

It is Honda's name for a system that sends drive to the front wheels on its own, through a viscous coupling, as the road surface changes. There is no lever and no switch; Honda's 1988 release billed it as the first of its kind on a cab-over kei commercial vehicle. Only the Attack version adds driver-selected extras: the UL and UR crawler gears and the rear diff lock.

Sources

Written by Farhad Musazada, owner of Skyline Kei Trucks

Farhad imports more than 300 kei trucks a year to Houston and meets buyers at the lot at 6100 Harvey Wilson Dr. He writes these guides from the paperwork our buyers take to the county tax office and the official sources listed on each page. Spotted something out of date? Email us and we will check it.

Ready to look? Browse kei trucks for sale in Houston, see what is in Houston now or arriving soon, or call or text (713) 385-9798.

All vehicles are sold by Wideway Motors LLC as is, with no warranty.