Tools & consumables needed
- Full metric socket/ratchet set, breaker bar, torque wrench (wide range).
- Impact wrench (optional).
- Dial indicator with magnetic base (0.01 mm resolution).
- Bearing race driver / press and arbor set.
- Bearing puller / slide hammer.
- Pinion depth gauge (or depth micrometer and reference mandrel) OR Hino pinion depth tool.
- Micrometer/feeler gauges.
- Shim spreader or pry bar and scale.
- Gear marking compound (Prussian blue or commercial gear paint).
- Seal driver, drift set, punch set.
- Hub/axle puller (if required).
- Shop press (or hydraulic press) for bearings.
- Clean solvent, rags, assembly lube, hypoid gear oil.
- New ring & pinion set (if changing ratio), bearings, races, pinion crush sleeve or pinion shims as required, carrier shims, oil seals, carrier bolts (often single‑use), locktight.
- Safety gear: gloves, safety glasses, jack stands, wheel chocks.

Safety precautions
- Work on a flat, level surface. Chock wheels, set parking brake. Support the vehicle securely on jack stands rated for the vehicle — never rely on a jack.
- Wear eye protection and gloves. Keep hands clear of springy components.
- Clean work area to avoid contamination of gears and bearings.
- Use correct lifting methods for heavy components (ring gear/carrier/pinion can be heavy).
- Dispose of used oil and parts per local regulations.

Overview of procedure
This covers setting up ring & pinion gear mesh/backlash and pinion bearing preload when assembling/adjusting a differential (typical when installing a different gear ratio or rebuilding a final drive). Exact torque, backlash, and pinion depth specs vary by model — always confirm Hino workshop manual values for the N04C chassis/axle. The steps below explain how to use the tools and what to watch for.

Step‑by‑step procedure

1) Preparation and removal
- Drain differential oil.
- Remove drive flange, axle shafts or half shafts, hub assemblies as required to access the carrier.
- Remove carrier cover and set aside gasket/clean mating surfaces.
- Mark relative positions of carrier, bearing caps (if used) and locking tabs for reassembly orientation.
- Remove carrier assembly (ring gear and carrier) and pinion assembly. Note and keep track of shims and side abutments. Clean all parts.

2) Inspect parts / replace consumables
- Inspect ring & pinion for wear or damage. If changing ratio, fit the new ring & pinion set (always replace the matched set).
- Replace pinion and carrier bearings and races if worn. Replace pinion crush sleeve (if used) or pinion shim kit per service manual. Replace carrier shims if damaged. Replace oil seals and carrier bolts if single‑use.

3) Fit ring gear to carrier
- If installing new ring gear onto the carrier, clean and use proper bolts and torque sequence. Apply Loctite if specified. Torque bolts to Hino spec.

4) Set pinion depth (critical)
- Install the pinion with the inner bearing and race. Use the pinion depth gauge or the Hino special tool to set pinion depth relative to the ring gear. If using shims, select the shim thickness that achieves the specified pinion depth.
- How the tool is used: the pinion depth gauge references the pinion flange and measures distance to a reference point on the ring gear mounting face. The measured depth is compared to spec; adjust with shims under pinion bearing or use crush sleeve technique as specified by Hino.
- Tighten pinion nut/temporary nut to hold assembly but do not final‑torque until preload is set.
- Install outer pinion bearing and race as needed.

5) Set pinion bearing preload
- For crush sleeve designs: tighten the pinion nut to compress the crush sleeve until specified rotational preload is achieved (measured as the torque to rotate the pinion using a beam or electronic torque wrench attached to the pinion flange). The Hino manual gives the target rotational torque (measure after seating and cooling as instructed).
- For shimmed pinion bearings: adjust shim thickness under the inner race until the correct preload (axial endplay) is achieved, then secure the pinion nut/retainer per manual.
- How the tool is used: use a low‑range torque wrench or dial on the pinion flange to measure the breakaway torque (rotation torque). Adjust shim/crush sleeve until the measured rotational torque matches OEM spec.

6) Install carrier with ring gear (initial set)
- Install bearings on carrier if removed. Place carrier in housing with initial carrier shims chosen to approximate centerline (refer to removed shim sizes; start with same total shim thickness or OEM starting value).
- Temporarily install bearing caps and torque to spec (or snug enough for dialing). Install a dial indicator with its tip on a tooth of the ring gear to measure backlash. The indicator’s base should be rigidly attached to the housing.

7) Measure backlash and adjust
- Rotate pinion slowly and observe the dial indicator while rotating through one or two revolutions. Backlash is the maximum movement measured.
- Adjust carrier shims to move the carrier laterally: adding shim to the side toward the ring gear moves the ring away; removing shim moves it closer. Typical method: change shim thickness on the side you want to move. Make incremental changes (0.05 mm steps) and remeasure until you achieve the specified backlash.
- Example: target backlash for many medium duty differentials is around 0.10–0.20 mm; but confirm Hino spec for exact value.

8) Check gear tooth contact pattern
- With backlash set, apply a thin layer of gear marking compound on several teeth of the ring gear.
- Rotate the pinion several full turns in the drive direction to create a contact pattern.
- Inspect pattern: it should be centered on the tooth surface (not too close to the toe, heel, root, or face). If the pattern is too deep toward toe/heel or face/root:
- Move pinion deeper (increase pinion depth) to move contact toward face.
- Move pinion out (reduce depth) to move toward root.
- Move carrier laterally (change shim) to move pattern toe/heel.
- Make small adjustments (shim changes, pinion shim/adjustment) and repeat marking until pattern is correct.

9) Final torque & assembly
- Once pattern and backlash are correct, tighten carrier bearing caps to final torque in the correct sequence. Use new bolts if required. Use thread locker if specified.
- Recheck backlash and contact pattern after final torquing — re‑adjust if necessary.
- Install seals, drive flange, axle shafts, and any removed components. Refill differential with correct grade and quantity of hypoid gear oil.

10) Break‑in and recheck
- After reassembly, run vehicle under light load for a short period and then recheck carrier bolt torque, pinion preload, and backlash after initial run‑in per Hino instructions (many manufacturers require rechecking after a few hundred km).
- Check for leaks and noisy operation.

Common pitfalls & how to avoid them
- Reusing bearings/races that are worn — always replace when in doubt. Worn races change measurement accuracy.
- Skipping pinion depth setup — leads to wrong contact pattern and premature wear. Use the proper pinion depth tool; do not guess.
- Over‑tightening pinion nut (crush sleeve) — can over‑preload bearings and cause failure. Measure rotation torque carefully and stop at spec.
- Incorrect backlash — too tight causes noise and heat; too loose causes chattering and broken teeth. Make incremental shim changes and measure after each change.
- Not using gear marking compound or misreading pattern — interpret patterns in both drive and coast directions if specified. Only small, centered patterns are acceptable.
- Reusing single‑use fasteners — replace as required.
- Contaminated gears/bearings — keep everything clean and lubricated with assembly lube when dry assembling.
- Forgetting to recheck after final torque and initial run‑in.

Replacement parts usually required when changing gear ratio or rebuilding
- Matched ring & pinion gear set (must be matched)
- New pinion and carrier bearings and races
- Pinion crush sleeve or pinion shims (as used)
- Carrier shims (as needed)
- Oil seals and gaskets
- Carrier bolts (if single‑use)
- Gear oil

Final notes
- Exact specifications (pinion depth, backlash, pinion preload, torques) for the Hino N04C vehicle axle must be taken from the Hino service manual for the vehicle/axle model — follow those specs exactly.
- If you do not have the special Hino pinion depth tool or torque/preload targets, do not guess — wrong setup will destroy the gearset quickly. Use a reputable shop manual or OEM data.

Done.
rteeqp73

N04C Engine being started on Bench for a customer. plenty of Engines 0771250250

How To Get A Hino Out Of Limp Mode Do not duplicate anything seen in this video, if you decide to do so, it's at your own risk”

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You come its removed up up with an low or fading parts only and it changes to extend in repairs. You might be replaced before warning screws until the oil is dry or connector.

- Safety first (read before doing anything)
- Wear safety glasses, nitrile gloves, and work clothes; diesel and fuel vapor irritate skin/eyes.
- Work in a well-ventilated area, no open flames, sparks, or smoking; have a suitable fire extinguisher rated for flammable liquids nearby.
- Disconnect the negative battery terminal before touching fuel system components to avoid sparks and accidental cranking.
- Relieve fuel system pressure before disconnecting lines to avoid spray; catch spilled diesel with an approved drip pan and dispose of waste fuel legally.
- Support the vehicle securely with jack stands if you must raise it; never rely on a jack alone.

- Basic tools (what they are and how to use them)
- Socket set (metric, 1/4" and 3/8" drive with extensions)
- Use to remove and install nuts/bolts on pump, brackets, and fuel lines. Choose the correct size socket, seat it fully on the fastener, and pull evenly to avoid rounding heads.
- Combination wrench set (metric)
- Use for nuts where a socket won't fit. Position the wrench fully over the flats and pull toward the handle; if stuck, use penetrating spray and steady, controlled force.
- Torque wrench (click-type, metric range)
- Required to tighten critical bolts to manufacturer torque. Set required torque and tighten smoothly until the wrench clicks; this prevents over/under-tightening that can cause leaks or stripped threads.
- Screwdrivers (flat and Phillips)
- Use for clamps, covers, and small fasteners; apply pressure directly and avoid using a screwdriver as a pry bar.
- Pliers (slip-joint and long-nose)
- Use to remove hose clamps and hold fittings; long-nose helps reach confined spaces. Avoid crushing soft fuel lines.
- Line wrenches/fuel line flare-nut wrenches
- Special open-end wrenches with extra grip for fuel line nuts; use to avoid rounding the hex on fuel fittings.
- Drain pan / fuel-safe container
- Place under vehicle to catch fuel when you disconnect hoses. Diesel must be contained and disposed of properly.
- Rags and absorbent pads
- Keep work area clean and to soak up spills; change contaminated rags responsibly.
- Fuel hose pinch-off pliers (soft-jaw) or suitable clamps
- Use to temporarily stop fuel flow in rubber lines without damaging them.
- Small pick / seal pick set
- Use to remove O-rings and seals carefully without scratching mating surfaces.
- Wire brush and cleaner (brake cleaner or diesel-safe cleaner)
- Clean mating surfaces before reassembly; do not spray into open injectors or intakes.
- Flashlight / inspection lamp
- Improves visibility in tight engine bays.
- Battery terminal puller (optional)
- Makes safe removal of terminals easier, reduces damage to terminals.

- Additional or special tools you are likely to need (why they are required)
- Torque angle gauge or calibrated torque wrench for specific torque sequences
- Some bolts require precise torque; prevents leaks and mechanical failure.
- Crankshaft/engine timing lock pin or alignment tool (Hino-specific if dealing with high-pressure injection pump timing)
- If working on the high-pressure injection pump or removing timing-driven pump, you must preserve pump-to-engine timing. Without the lock tool you risk incorrect timing, poor running or engine damage.
- Fuel pressure gauge and bleed/priming tool (hand pump with adapter)
- Useful to verify fuel pressure and to prime the system after installation to remove air; prevents hard starting and injection damage.
- Injection pump puller or specialist removal tool (if pump is seized)
- Some pumps are pressed or tightly fitted; a puller prevents damage during removal.
- Dealer/Service diagnostic tool or ECU reprogramming capability (for some common-rail systems)
- After replacing a high-pressure pump or certain components the ECU may need reinitialization or calibration; without this you may get fault codes or performance issues.
- Replacement vacuum or fuel line fittings and banjo washers
- Many fuel connections use crush washers that must be replaced to prevent leaks.

- Parts commonly replaced or recommended when working on the fuel pump (what and why)
- Fuel pump assembly (low-pressure lift pump or high-pressure injection pump)
- Replace if leaking, not building pressure, noisy, or failed. Low-pressure (lift) pumps are often mechanical/electric and easier to replace; high-pressure pumps control injection timing/pressure and are more critical.
- O-rings, seals, and gaskets (pump mounting gasket, fuel line O-rings, banjo washers)
- Always replace soft seals when disconnecting lines or removing the pump to avoid fuel leaks.
- Fuel filter(s) and water separator element
- Replace when servicing pump; a clogged filter can starve the pump and introduce air.
- Fuel lines and clamps (rubber hoses or hard lines showing corrosion/damage)
- Replace cracked/soft hoses or corroded metal lines to prevent leaks and air ingress.
- Banjo bolts and crush washers
- Replace when removed; they seal high-pressure connections.
- Pump mounting bolts (if damaged or corroded)
- Replace any that are stretched or have damaged threads.
- Return line components and check valves (if leaking or malfunctioning)
- Faulty check valves cause pressure issues; replace as needed.

- High-level workshop procedure (safe, workshop-style overview; for beginners — do not improvise on critical timing)
- Verify which pump you are addressing: low-pressure feed (lift) pump vs high-pressure injection pump; procedures and risk differ.
- Prepare workspace: park level, engine cold, isolate battery negative, place drip pan, wear PPE.
- Relieve fuel pressure: follow Hino procedure (usually drain fuel filter and open bleed screw or crank engine with fuel pump fuse removed) to avoid spray.
- Label and photograph routing of fuel lines and electrical connectors before removal to ensure correct reassembly.
- Remove obstructing components to access pump (air cleaner, intake ducting, brackets). Keep fasteners organized in labeled bags.
- Disconnect fuel inlet/outlet lines using line wrenches; cap lines to keep contaminants out.
- Remove electrical connections and vacuum lines (if applicable) from pump; mark or photograph each connector.
- Unbolt pump mounting bolts using appropriate sockets/wrenches; use penetrating oil on stubborn bolts and let soak.
- Extract pump carefully; if stuck, use appropriate puller or gentle prying at mounting points—avoid bending or damaging mating surfaces.
- Replace pump seals/O-rings and any crush washers; fit new gasket on mounting surface and clean surface with suitable cleaner.
- Install replacement or rebuilt pump: align per original orientation and torque bolts to factory specs with a torque wrench.
- Reconnect fuel lines with new crush washers/O-rings as required; tighten line fittings with flare-nut or line wrenches to correct torque—hand snug then small quarter-turn with wrench to avoid over-tightening.
- Reconnect electrical connectors and vac lines; re-install removed components.
- Prime the fuel system: use hand primer or ignition cycles to operate the fuel pump and bleed air at the filter bleed screw until clean diesel appears and system pressure stabilizes.
- Check for leaks at all fittings while priming; tighten any loose fittings.
- If the high-pressure/injection pump was removed or timing disturbed:
- Use engine timing lock tools and follow Hino factory timing procedure exactly when reinstalling.
- If you do not have the timing tool or experience, do not proceed — incorrect timing risks major engine damage. Have a professional complete the timing/commissioning and any ECU procedures.
- Start engine and monitor for leaks, abnormal smoke, and proper idle. Let engine warm, re-check torque on fittings, and verify no fault codes.

- Important notes and cautions (no-nonsense)
- If working on the high-pressure injection pump, special tools and calibration are usually required; this is not a recommended DIY job for a complete novice. Incorrect timing or improper installation can destroy the engine.
- Always replace soft sealing items (O-rings, crush washers, fuel filter) when accessing the pump—reusing them is the most common cause of leaks.
- Have a service manual or the Hino factory workshop manual for the N04C for torque values, timing marks, pin locations, and model-specific procedures; generic instructions are not a substitute for model-specific torque and timing data.
- If you lack a torque wrench, fuel pressure gauge, or timing tools, buy or rent them — they are required to do the job correctly and safely.
- If the pump is noisy, starves under load, or fails to build proper pressure, replacement is reasonable; if only marginal, rebuild kits exist but must be installed and calibrated by an experienced technician.

- Quick checklist of what you must have before starting
- Safety gear: gloves, glasses, fire extinguisher
- Basic toolset + torque wrench + line wrenches
- Fuel-safe drain pan and rags
- Replacement seals, O-rings, crush washers, and fuel filter(s)
- Fuel primer/pump or means to bleed the system
- Hino N04C service manual (for torque and timing)
- Optional but highly recommended: timing lock tool and fuel pressure gauge

- Final pragmatic advice
- For the low-pressure lift pump: most competent DIYers with basic tools can replace it following the steps above.
- For the high-pressure injection pump: plan to either have the special Hino timing tools and manual or hand the job to a qualified diesel technician; expect the pump replacement or calibration to possibly require dealer-level diagnostic and programming tools.
- Replace filters and all soft seals whenever you open the fuel system; test carefully for leaks and proper pressure before road testing.

No Yapping.
rteeqp73