Login to enhance your online experience. Login or Create an Account
Logo
Shopping Cart

Shopping Cart 0 Items (Empty)

Isuzu NPR NQR NPS NKR NHR N SERIES TRUCK Workshop Manual Digital Download

Safety (read once, no yapping)
- Work on a level surface, parking brake on, wheels chocked. Never rely on a jack alone — always use jack stands rated above vehicle weight. Wear gloves and eye protection. If unsure at any point, get professional help.

Tools (basic tools first, then extra/optional). Each tool: what it is, why needed, how to use it.
- Floor jack (2–3 ton capacity)
- What: Hydraulic trolley jack used to lift the truck.
- Why: To lift axle or wheel to remove wheel and access suspension.
- How to use: Position under manufacturer jacking point, pump handle until wheel clears, then place jack stand under secure frame point and lower jack slightly so stand bears the weight. Do not crawl under on the jack alone.
- Jack stands (pair, rated >= vehicle weight)
- What: Mechanical supports to hold vehicle after lifting.
- Why: Safe support while you work.
- How to use: Set at recommended support point, lock at correct height, lower the vehicle onto stands. Verify vehicle is stable before working.
- Wheel chocks
- What: Blocks to prevent rolling.
- Why: Prevents vehicle movement.
- How to use: Place behind/forward of wheels remaining on ground.
- Lug wrench / breaker bar with appropriate socket (1/2" or 3/8" drive)
- What: For loosening lug nuts and tight bolts.
- Why: Lug nuts and many suspension nuts require high torque to remove.
- How to use: Use breaker bar to break tight lug nuts while wheel is on ground; use correct socket size and steady force.
- Metric socket set (3/8" and 1/2" drive), deep sockets included (common sizes 10–32 mm)
- What: Ratchet sockets for nuts/bolts.
- Why: Most suspension hardware is metric; deep sockets required for long studs.
- How to use: Select correct size, use ratchet or breaker bar; keep sockets square to fastener to avoid rounding.
- Combination wrench set (metric)
- What: Open-end and box-end wrenches.
- Why: For holding bolt heads while turning nuts; tight spaces where sockets don’t fit.
- How to use: Use box end for better grip; apply steady controlled force.
- Torque wrench (click-type, 10–250 Nm / up to ~200 ft-lb)
- What: Tool to tighten bolts to specified torque.
- Why: Suspension fasteners require correct torque for safety and to avoid loosening or part failure.
- How to use: Set desired torque, tighten slowly until click. Refer to service manual for torque values.
- Breaker bar (18–24")
- What: Long non-ratcheting bar.
- Why: Provides leverage for seized or high-torque bolts.
- How to use: Use steady force, avoid sudden jerks. Use penetrating oil first on rusty bolts.
- Penetrating oil (e.g., PB Blaster, WD-40 Specialist)
- What: Chemical to loosen rusted fasteners.
- Why: Prevents rounding bolts and makes removal possible.
- How to use: Spray on threads, wait 10–20 minutes (or longer on heavy rust), reapply if needed.
- Hammer and rubber mallet
- What: Steel hammer and soft mallet.
- Why: Knock loose stuck components (e.g., sway bar links) or seat parts.
- How to use: Tap gently; use rubber mallet to avoid damaging parts.
- Pry bar (crowbar / large screwdriver)
- What: Leverage tool for separating parts.
- Why: To pry control arms, separate bushings or align holes for bolts.
- How to use: Use controlled pressure; protect components with block of wood to avoid damage.
- Ball joint separator (pickle fork) or press-style puller
- What: Tool to separate ball joint from steering knuckle.
- Why: Necessary to remove ball joints without damage.
- How to use: Fit and strike with hammer (pickle fork) or use mechanical puller to press joint apart. Use protective eyewear.
- Spring compressor or leaf spring clamp / C-clamp (for coil springs or semi-independent setups)
- What: Compressors for coil springs or clamps for leaf springs.
- Why: Coil springs under tension are dangerous; compressors allow safe removal. Leaf springs may need to be clamped or supported when removing U-bolts.
- How to use: Follow manufacturer instructions exactly for spring compressors; compress evenly. For leaf springs, support axle and slowly loosen U-bolts.
- Impact wrench (electric or pneumatic) — optional but very helpful
- What: High-torque power tool to remove stubborn bolts.
- Why: Saves time and reduces manual effort, loosens rusted fasteners.
- How to use: Use correct sockets rated for impact tools; keep steady. Use air/power per tool manual. Still finish with torque wrench to specified torque.
- Grinder or reciprocating saw (Sawzall) — optional, for cutting U-bolts or extremely rusted bolts
- What: Power cutting tool.
- Why: Sometimes U-bolts or studs are corroded and must be cut off.
- How to use: Use with eye/ear protection, cut carefully, avoid damage to axle or brake lines.
- Wire brush and rags
- What: For cleaning threads and mounting surfaces.
- Why: Clean mating surfaces improve fit and prevent corrosion.
- How to use: Brush rust/dirt, wipe clean with rag and solvent if needed.
- Grease, anti-seize, and thread locker (Loctite)
- What: Lubricants and locking compounds.
- Why: Prevent corrosion and ensure correct torque retention where required.
- How to use: Apply anti-seize to bolts that may need later removal; use thread locker on bolts specified by manual; grease bushings as required.
- Torque angle gauge or torque-to-yield tools (if specified by manual) — optional
- What: For bolts specified by angle rather than torque.
- Why: Some critical bolts are tightened to angle spec.
- How to use: Use per instructions; most hobbyists will instead replace such bolts and follow manual.
- Service manual for your specific Isuzu model and year (strongly recommended)
- What: Factory or aftermarket repair manual with torque specs, diagrams, disassembly sequence.
- Why: Suspension specifics and torque values vary by model; manual gives correct procedures and safety info.
- How to use: Follow disassembly diagrams and torque tables.

Common replacement parts (what they are, why you’d replace them)
- Shock absorbers
- What: Dampers front and rear.
- Why replace: Leaking oil, no damping, excessive bounce, uneven tire wear. Replacing restores ride control.
- Leaf springs (rear) or control arms/torsion bars (front) depending on model
- What: Leaf packs or torsion bars/control arms provide support.
- Why replace: Broken leaves, sagging springs, bent control arms, or damaged torsion bars cause low ride height and handling problems.
- Bushings (shackle, spring eye, control arm)
- What: Rubber/urethane cushions between metal parts.
- Why replace: Worn bushings cause clunks, play, misalignment; replacement restores proper geometry and reduces noise.
- U-bolts and nuts
- What: Clamp axle to leaf spring.
- Why replace: Often corroded or stretched — they should be replaced whenever removed; they are critical for axle retention.
- Ball joints, tie rod ends, wheel bearings
- What: Steering and hub joints.
- Why replace: Excessive play, noise, or wear affects steering and safety.
- Sway bar links/bushings
- What: Stabilizer link components.
- Why replace: If loose or worn they cause clunks and reduced roll control.
- Mounting bolts and nuts (hardware)
- What: Fasteners.
- Why replace: Many suspension bolts are torque-to-yield or corroded — replace if damaged or if manual requires.
- Shock bushings/mounts
- What: Rubber mounts for shocks.
- Why replace: If torn or perished, shocks don’t function properly.

Inspection and diagnosis (what to check, how to use tools)
- Visual inspection
- Use flashlight; look for oil on shocks, cracked/broken spring leaves, torn bushings, rusted/loose U-bolts, missing hardware.
- Wheel play test
- Use jack and stands: lift wheel, grasp wheel at 12 and 6 o’clock and rock — play suggests wheel bearing or ball joint. Also test at 3 and 9 for tie rod lash.
- Bounce test (basic)
- Push down on corner of vehicle and release: excessive bounce suggests worn shocks.
- Measure ride height and compare left/right
- Use tape measure; sag indicates broken/weak springs.
- Listen for noises during slow drive (if safe)
- Note clunks/knocks, which indicate worn bushings, loose U-bolts, or worn joints.

General repair actions and how to perform them (bulleted tasks; keep model-specific notes in manual)
- Replace shock absorbers (typical easiest suspension job)
- Tools: jack, stands, socket set, wrenches, penetrating oil, torque wrench, pry bar if needed.
- Procedure: Lift axle, remove wheel, spray bolts with penetrating oil, support axle, remove lower and upper shock bolts, remove shock, compare new vs old to confirm length and mounts, fit new shock, tighten to torque spec, lower and torque wheel.
- Why replace: Leaks or loss of damping. Replace in pairs (both front or both rear) for balanced handling.
- Replace leaf springs / U-bolts (rear)
- Tools: jack, stands, wheel chocks, breaker bar, socket set, pry bar, C-clamp or spring clamp, torque wrench, new U-bolts, grinder or sawzall if bolts are corroded, penetrating oil.
- Procedure: Support axle with jack under axle tube, remove U-bolts after spraying, remove shackle or spring eye bolts, lower axle slightly to relieve spring tension, remove spring, inspect perches and bushings, fit new spring and replace U-bolts (always new U-bolts), torque progressively to spec. Use new bushings if worn.
- Why replace: Broken leaves, sag, severe corrosion; U-bolts must be replaced if removed or corroded.
- Replace control arm or bushings (front)
- Tools: jack, stands, socket set, press or hammer/punch for bushing removal (or bushing tool), pry bar, ball joint separator, torque wrench.
- Procedure: Remove wheel, detach ball joint and control arm pivot bolts, press out old bushing or remove old control arm, install new bushing/arm, torque to spec. If pressing bushings, ensure even, slow pressing to avoid damage.
- Why replace: Worn bushings or bent arms cause handling issues and uneven tire wear.
- Replace ball joints or tie rod ends
- Tools: ball joint press or separator, socket set, pry bar, hammer, torque wrench.
- Procedure: Remove wheel, separate joint from knuckle (press or use separator), remove retaining fastener, install new joint, torque to spec, recheck wheel alignment.
- Why replace: Excessive play, clunking, steering wander.
- Torsion bar inspection / replacement (if fitted)
- Tools: torsion bar adjusting tool or strut; large sockets/wrenches, jack/stands, torque wrench.
- Procedure: Unlock torsion bar adjuster, inspect for cracks, replace if broken. Replacement requires correct preload and adjuster torque per manual.
- Why replace: Broken torsion bars cause dropped front end or asymmetric ride.
- Bushing replacement (shackle, spring eye)
- Tools: press or hammer/punch, sockets, grease.
- Procedure: Remove shackle/spring bolts, press out old bushing, press in new bushing with suitable tool, reassemble and torque.
- Why replace: Worn bushings cause clunking and misalignment.
- Replace sway bar links/bushings
- Tools: sockets/wrenches, penetrating oil, torque wrench.
- Procedure: Remove old links/bushings, install new parts, torque to spec.
- Why replace: Reduce roll control loss and eliminate clunks.
- Wheel bearing service or replacement
- Tools: socket set, hub puller, press or special tool, torque wrench.
- Procedure: Remove hub and bearing, press out bearing, press in new bearing, reassemble. Some hubs are serviceable; others replaced as unit.
- Why replace: Noise, play, or heat from failed bearing; safety-critical.

How to use common tools safely and effectively (short practical tips)
- Jack and stands: Always lift at manufacturers’ jacking points. Raise to comfortable working height, place stands under solid frame, gently lower so stand holds the weight. Shake vehicle slightly to confirm stability.
- Breaker bar vs impact wrench: Use breaker bar to initially break loose stubborn bolts; impact wrench can remove quickly but always finish torque with torque wrench to correct value.
- Penetrating oil: Spray and wait; don’t force a bolt that’s stuck — work it back and forth with breaker bar to avoid round-off.
- Torque wrench: Clean threads, apply anti-seize where permitted, finger-tighten first, then final torque in steps. Store torque wrench at lowest setting when not in use.
- Spring compressors: Use matched pair and compress evenly on opposite sides; never work with a single compressor or without proper training — coil springs store energy and can kill.

Common pitfalls and requirements
- Replace U-bolts whenever removed or if corroded — critical safety item.
- Always replace both shocks on an axle together for balanced handling.
- Many suspension bolts are torque-to-yield or one-time-use — consult manual; replace if required.
- After major suspension work, get a professional wheel alignment immediately — control arm, tie rod, or spring changes will alter alignment.
- Rusted bolts: heat and penetrating oil help; cutting may be necessary — cutting requires care around brake lines and fuel lines.
- Safety-critical components (steering, ball joints, bushings that affect alignment): if you’re a complete beginner, consider having a mechanic inspect your work or perform the job.

Final checks and test
- Re-torque all fasteners to spec after first 100–200 km of driving (re-torque procedure).
- Check for leaks, noises, and ride height.
- Get wheel alignment and verify brake function before road testing.

Replacement part buying guidance
- Use OEM or high-quality aftermarket parts matched to your Isuzu N-series model/year.
- Bring old part to parts supplier to ensure correct match (length, mount style).
- Replace bushings with OEM or polyurethane depending on desired NVH and durability.
- Replace all U-bolts in a kit (same grade, correct diameter and length).

Concise safety repeat (last word)
- Never work under a vehicle supported only by a jack. Use stands, verify stability, follow torque specs from the service manual, and get alignment after suspension repairs.

No questions asked.
rteeqp73

You Might Also Like...

Kryptronic Internet Software Solutions