### Tools Required

- **Socket Set**:
- **Description**: A set of sockets in various sizes that fit onto a ratchet or wrench.
- **Usage**: Use these to remove bolts securing the transmission cover and solenoid pack. Ensure you have the correct size to avoid stripping the bolts.

- **Ratchet and Extension**:
- **Description**: A ratchet is used with sockets to turn bolts; an extension helps reach bolts in tight spaces.
- **Usage**: Attach the socket to the ratchet, and use the extension if bolts are deep-set or hard to reach.

- **Torque Wrench**:
- **Description**: A tool used to apply a specific torque to fasteners.
- **Usage**: After installing the new solenoid pack, use the torque wrench to tighten the bolts to the manufacturer's specified torque settings to ensure proper sealing and operation.

- **Screwdriver Set**:
- **Description**: A set of flathead and Phillips screwdrivers.
- **Usage**: May be needed to remove any screws securing the transmission cover or wiring harness.

- **Pliers**:
- **Description**: A gripping tool for holding or bending objects.
- **Usage**: Use pliers to disconnect any wiring connectors or hold small components while working.

- **Clean Rags**:
- **Description**: Cloths for cleaning and wiping surfaces.
- **Usage**: Use to clean any fluid spills and wipe surfaces before installing the new solenoid pack.

- **Sealant or Gasket Maker**:
- **Description**: A compound used to seal joints against leakage.
- **Usage**: Apply to the transmission cover before reassembly if the old gasket is damaged or missing.

### Replacement Parts

- **Transmission Solenoid Pack**:
- **Reason for Replacement**: The solenoid pack controls fluid flow in the transmission. If it’s faulty, it can cause shifting issues or transmission failure.
- **Selection**: Purchase a compatible solenoid pack specifically designed for the Massey Ferguson MF35.

- **Gaskets**:
- **Reason for Replacement**: Old gaskets may become brittle, causing leaks when reassembling.
- **Selection**: Obtain a new gasket for the transmission cover if the existing one is worn or damaged.

### Step-by-Step Replacement Process

- **Prepare the Workspace**:
- Ensure safety by parking the tractor on a flat surface and engaging the parking brake. Disconnect the battery to prevent electrical shorts.

- **Drain Transmission Fluid**:
- Locate the drain plug on the transmission. Use a socket and ratchet to remove it and drain the fluid into a clean container. This step prevents spills during solenoid pack removal.

- **Remove the Transmission Cover**:
- Using the socket set, unbolt the transmission cover. If screws are present, use the appropriate screwdriver. Keep track of all bolts and screws.

- **Disconnect the Old Solenoid Pack**:
- Locate the solenoid pack, usually attached to the transmission housing. Disconnect any wiring harnesses carefully, using pliers if needed.

- **Remove the Old Solenoid Pack**:
- Unbolt the solenoid pack using the socket set. Lift it off gently, ensuring no debris falls into the transmission.

- **Install the New Solenoid Pack**:
- Place the new solenoid pack in position and bolt it down securely. Make sure to connect wiring harnesses correctly.

- **Reassemble the Transmission Cover**:
- If using a new gasket, place it on the cover. If not, clean the surface and apply sealant as required. Reattach the cover using the bolts, ensuring they are tightened to the specified torque.

- **Refill Transmission Fluid**:
- Replace the drain plug and refill the transmission with the appropriate fluid type for the MF35.

- **Reconnect the Battery**:
- Reconnect the battery and check for any leaks or issues.

By following these steps and using the tools as described, you will successfully replace the transmission solenoid pack on a Massey Ferguson MF35 tractor.
rteeqp73

Below are step-by-step instructions, tools, safety points, how tools are used, replacement parts likely required, and common pitfalls for repairing the gearbox housing on a Massey‑Ferguson MF35. Assume you have a flat, level work area, service manual for torque and clearance specs, and basic mechanical experience. Follow the manual for exact torques and clearances — I do not supply specific torque numbers here.

SAFETY PRECAUTIONS
- Disconnect battery and remove ignition key.
- Wear safety glasses, gloves, steel‑toe boots. Use hearing protection when using power tools.
- Use rated engine/transmission jacks, lifting chains, and jack stands. Never rely on a jack alone — support with stands.
- Drain all fluids before loosening bolts. Clean spilled oil immediately.
- Cast iron housings can crack and spring — keep hands clear and use proper lifting.
- If welding cast iron, do that only in a well‑ventilated area with appropriate respiratory protection; preheat and controlled cool-down are required.
- If machining (line boring, reaming), use qualified machine shop; avoid DIY unless you have equipment and experience.

TOOLS NEEDED (typical)
- Full metric socket and spanner set, deep sockets, breaker bar.
- Torque wrench (sufficient range for gearbox bolts).
- Pry bars, screwdrivers, drift punches, hammer.
- Hydraulic transmission jack or engine hoist with adapter plate.
- Gearbox/bearing pullers, slide hammer.
- Hydraulic press (10–20 ton) for bearing removal/fitment.
- Circlip pliers, snap ring tools.
- Bearing driver set / seal driver.
- Dial indicator with magnetic base (for backlash, runout, endplay).
- Feeler gauges, micrometer, vernier caliper.
- Dead blow hammer, soft mallet.
- Penetrating oil, gasket scraper, parts cleaner.
- Thread chaser / tap & die set (for bolt threads).
- Welding equipment (nickel rods or cast‑iron welding rods) OR brazing kit AND temperature gauge (only for small cracks; prefer machine shop).
- Fine grit abrasive and wire brush, bench grinder (for light cleaning).
- RTV gasket maker and recommended gasket set.
- Replacement bearings, seals, gaskets, bushes, studs/bolts as needed.
- Marking paint / permanent marker and container to bag small parts for organization.
- Shop manual or exploded diagrams for MF35.

OVERVIEW OF THE JOB
- Remove gearbox from tractor, disassemble gearbox to access housing, inspect, repair or replace housing, replace bearings/seals/gaskets, reassemble with correct shims and clearances, refit to tractor and test.

STEP‑BY‑STEP PROCEDURE

1) Preparation
- Park tractor, set parking brake, chock wheels. Disconnect battery.
- Drain gearbox oil into a clean container; dispose/label properly.
- Clean around gearbox to reduce dirt ingress during disassembly.
- Take photos from multiple angles of linkages and position of components before removal.

2) Disconnect external components
- Remove linkage rods, shift levers, remote levers, PTO linkage and any external control rods. Use marking tags to keep track.
- Remove clutch pedal linkages as required to separate gearbox from clutch housing.
- Remove PTO shaft and any brake/PTO cover plates.
- Remove speedometer cable if present.

3) Support and remove gearbox from tractor
- Place engine/transmission jack under gearbox. If gearbox is bolted to engine block, support engine or use engine hoist to prevent movement when unbolting.
- Unbolt bellhousing/gearbox mounting bolts (keep bolts in order). Lower gearbox slowly and clear any wires or lines.
- Lift gearbox clear and move to sturdy bench or transmission stand.

4) Initial teardown on bench
- Photograph and mark orientation of selector forks, gears, and shafts.
- Remove external covers, speedometer drive, and inspection plates.
- Remove snap rings and bearing caps as per manual.
- Using press or puller, remove input shaft, mainshaft, layshaft and associated gears. Use a hydraulic press for tight bearings; apply heat (carefully) to loosen stubborn bearings only if necessary.
- Use circlip pliers for internal snap rings; keep grooves clean.
- Remove all bearings, seals, and bushes. Use bearing puller or press; heated bearing races expand for easier removal (heat controlled with heat gun or in an oven).

How specific tools are used:
- Hydraulic press: center the shaft, support adjacent parts, press the bearing off the shaft or press new bearings on using correct drivers to avoid damaging races.
- Bearing puller/slide hammer: attach to bearing inner or use pilot adapter; pull straight to avoid damaging shaft journals.
- Dial indicator: mount on a stable reference and indicate on shaft teeth or a fixed collar to measure endplay/backlash. Rotate gearbox slowly and note max/min.
- Circlip pliers and bearing driver: select correct size driver so force is applied to outer race when installing bearings; use even pressure on press.

5) Housing inspection
- Clean housing thoroughly with solvent and wire brush.
- Visually inspect for cracks around bolt holes, bearing bores, main mounting faces, and mating surfaces.
- Use dye penetrant for crack detection: clean, apply penetrant, rinse, apply developer, inspect under good light.
- Check bearing bores with micrometer or bore gauge for ovality, wear, and size. Measure shaft journals too. If bores are out of round beyond spec, machining is required.
- Check mating faces for warp or damage; measure flatness with straightedge.
- Check for stripped threads; run a thread chaser to clean or replace studs/insert helicoil as needed.

Repair decisions:
- Small, isolated hairline cracks on non‑critical areas: can be welded by an experienced technician using cast‑iron welding techniques (preheat, nickel electrodes or special cast‑iron rods, controlled cool-down).
- Cracks in bearing bores, load paths, or heavily distorted housings: replace housing or send to machine shop for sleeving/line‑boring or full replacement. Sleeving/line‑boring requires precise machining to restore bore alignment and diameter.
- Worn bores beyond available repair tolerance: fit hardened sleeves or replace housing.

6) Welding/repair of cracks (if chosen)
- Clamp housing and remove all oil and grease. Preheat housing slowly to 250–350°C (depends on mass) — check service manual or welding guidelines. Mark positions to maintain orientation.
- Use nickel rods or specialized cast‑iron welding rods. Make shallow weld beads to avoid excessive heat build-up; peen each bead if recommended; allow slow cooling (wrap in insulation like welding blanket) to prevent quench cracking.
- Alternatively, for small cracks in non‑critical areas, brazing with bronze rod can be used.
- After repair and full cool down, grind smooth and check for leak tightness. Pressure test if feasible (low pressure) to confirm integrity.
- If housing bores were distorted and welded, final machining is necessary to restore bore size and geometry.

7) Machining (when required)
- For damaged bearing bores or misalignment, send housing to a qualified machine shop to:
- Line‑bore or sleeve bearing bores to correct size and alignment.
- Reface mating surfaces if warped.
- Re‑tap or install helicoils for stripped threads.
- After machining, clean thoroughly to remove chips/debris.

8) Replace worn parts
- Replace all bearings showing wear — mainshaft, layshaft, input, output bearings. It’s common practice to replace all gearbox bearings and seals during a housing repair.
- Replace oil seals and gaskets.
- Replace selector forks or rails if worn or bent.
- Replace shims and spacers as required; do not reuse if deformed.
- Replace studs/bolts that show stretch or damaged heads; use grade‑matched bolts and new lock washers/nuts.

9) Reassembly on bench
- Clean all components and apply light assembly oil.
- Press new bearings onto shafts using proper drivers; ensure bearings are seated squarely.
- Fit shafts and gears back into housing in order, aligning with marks made earlier.
- Refit selector forks, synchronizers (if fitted), and spacers. Ensure fork orientation matches original.
- Adjust endplay and thrust clearances: use feeler gauges and/or dial indicator to measure axial movement; add/remove shims as per manual until specs met.
- Set gear mesh/backlash: mount the layshaft and mainshaft, fit gears and bearings, use dial indicator pressed against a gear tooth and rotate gear while holding the counterpart; adjust shims to achieve correct backlash (consult manual — if unavailable, typical gear backlash for tractor gearsets is small, often 0.05–0.25 mm — but use manual values).
- Apply correct torque to bearing caps and housing bolts per manual. Use threadlocker where specified.
- Fit new gaskets and seals; install inspection covers and breathers.

How to use dial indicator for backlash:
- Securely mount dial indicator so tip contacts a tooth on the stationary gear, then rock the cooperating gear back and forth. The reading between extremes is backlash. Adjust by adding/removing shims on bearing seats or repositioning shaft to achieve desired reading.

10) Final assembly and refit to tractor
- Clean mating surfaces, fit new gasket or apply sealant per manual.
- Lift gearbox carefully into position with transmission jack; align dowels and seat.
- Refit mounting bolts, torque evenly to spec.
- Reconnect linkages, PTO, speedometer cable, and clutch linkage.
- Refill gearbox with correct type and amount of oil.
- Reconnect battery.

11) Testing
- Start engine and run through all gears with tractor stationary; check for abnormal noises, shifting difficulty, leaks.
- Perform a road test under light load, retorque bolts after initial run‑in if required.
- Recheck oil level and check for leaks after 1–2 hours of operation.

COMMON PITFALLS TO AVOID
- Not supporting engine or gearbox properly — leads to dropped or damaged parts.
- Not labeling shift forks/shafts orientation — reassembly problems and shifting failure.
- Reusing worn bearings and seals — short life and repeat failure.
- Welding cast iron without preheat or using wrong filler — causes new cracks or brittle welds.
- Attempting to DIY line‑boring or sleeving without equipment/skill — leads to misalignment and rapid gear/bearing failure.
- Failing to check/restore gearbox bore alignment after welding — results in premature bearing wear.
- Not measuring and setting backlash/endplay correctly — leads to gear noise, wear, or failure.
- Over‑torquing bolts or reusing stretch bolts — causes bolt failure and distortion.
- Reassembling with dirty parts — abrasive contaminants shorten bearing life.

REPLACEMENT PARTS USUALLY REQUIRED
- Mainshaft and layshaft bearings.
- Input/output bearings and thrust washers.
- Oil seals (input, output, speedometer drive).
- Gaskets and gasket maker.
- Selector forks / rails if worn.
- Shims and spacers.
- Studs/bolts/nuts and lock washers.
- Possibly full replacement gearbox housing if cracked severely or bores are beyond repair.
- If welding is used: appropriate welding rods (nickel/cast‑iron rods) or brazing materials.

WHEN TO SEND TO A MACHINE SHOP / REPLACE HOUSING
- Bearing bores out‑of‑round, mismatched alignment, or worn beyond acceptable limits.
- Cracks in load bearing areas (around main bearings, mounting bosses).
- Multiple threaded holes stripped in critical areas.
- If you lack the tools (press, line‑bore, welding preheat equipment) — better to replace or have shop repair.

FINAL NOTES
- Keep an organized parts tray and take photos during disassembly — this saves hours at reassembly.
- Replace bearings and seals in sets — it’s almost always cheaper in time and money to renew the wear items while housing is open.
- If unsure about welding cast iron or doing machining, send housing to a reputable workshop experienced with tractor transmissions.

That’s the full practical workflow. Follow your MF35 service manual for the precise torque and clearance values before final assembly.
rteeqp73

Bottom line first: the MF35’s cooling fan(s) are a simple, mechanical part of the engine’s cooling system. If the fan or its drive fails the engine will overheat quickly and can suffer serious damage (warped head, blown head gasket, seized engine). Below is a beginner-friendly, component-by-component explanation, how the system works, why repairs are needed, what commonly goes wrong, and clear step‑by‑step guidance for inspecting, removing and fitting the fan (and related fixes). No fluff.

What the cooling system is doing (big‑picture theory, with analogies)
- The radiator is the heat exchanger that dumps engine heat into the air. Think of it as a car’s “air conditioner condenser but in reverse”: hot coolant flows through tubes and air runs across the fins to carry heat away.
- The fan is the windmill that forces air through the radiator when the tractor is slow or stationary. Without the fan the radiator only moves air when you drive.
- The water pump circulates coolant through the engine and radiator—it’s the circulatory system’s heart.
- The thermostat is a temperature‑controlled gate that keeps the engine warm until it reaches operating temperature, then opens to let coolant flow through the radiator.
- The fan shroud is like a funnel that makes the fan’s air go through the radiator instead of around it—big gains in effectiveness.
If any part of this chain is broken the fan can’t move heat away and the engine overheats.

Main components you’ll see on an MF35 (what each part does)
- Fan blades / fan assembly: metal blades bolted to the fan hub. They produce the airflow. On an MF35 this is usually a fixed mechanical fan (no electric fan clutch).
- Fan hub / boss: the central piece the blades bolt to. It bolts to the water‑pump pulley or front pulley depending on setup.
- Fan pulley (if present): the pulley the belt runs on that drives the fan/water pump. Often the fan is directly bolted to the water pump shaft/pulley.
- Fan belt (V‑belt): transfers rotation from crank pulley to water pump/fan and often the generator/dynamo.
- Water pump: contains the impeller and bearings; it forces coolant around the engine. The fan is often mounted to its front.
- Fan shroud: channel that directs airflow through the radiator.
- Radiator: core with tubes and fins that transfer heat from coolant to air.
- Radiator cap: pressure cap that raises boiling point and lets coolant escape to overflow if overpressurized.
- Hoses: upper/lower radiator hoses move coolant.
- Thermostat: temperature‑controlled valve in the coolant circuit.
- Bearings/seals: water pump bearings let the pump/fan spin smoothly; seals keep coolant in.
- Fasteners/bolts: secure fan to hub/pump; check for looseness or broken studs.

Common failure modes and how they cause overheating (what can go wrong)
- Broken/cracked fan blades — reduces airflow and causes vibration/imbalance.
- Loose fan bolts or cracked hub — fan can wobble, rub shroud or drop.
- Worn water‑pump bearings — noisy fan, rough spin, eventual seizure (no coolant circulation).
- Worn/loose or broken V‑belt — fan not turning at correct speed or not at all.
- Missing/broken shroud — airflow bypasses radiator and cooling efficiency drops drastically.
- Clogged radiator fins or internal core — airflow or coolant flow is limited.
- Stuck thermostat — either stays closed (no coolant to radiator) or stuck open (runs cool but not a usual overheating cause).
- Air trapped in the system — can cause local hotspots and overheating.
- Wrong/old coolant or corrosion — boiling point lowered, or deposits/chokes passages.
All can lead to overheating; overheating causes head gasket failure, warped head, or seized engine.

Tools and supplies you’ll need (basic list)
- Socket and spanner set, screwdrivers
- Fan/gear puller set (hand puller) — in case fan is stuck on hub
- Pliers, hammer, penetrating oil
- Torque wrench (if you have one; consult manual for critical bolts)
- Drain pan, rags, gloves, safety glasses
- Replacement fan or fan blades/hub, new belt, possible water pump (if bearings/seal bad), gaskets, coolant
- Wire brush for rust, degreaser, radiator comb (for fin straightening)
- Anti‑seize or threadlocker (as appropriate)
- Shop manual for MF35 for torque specs and specifics

Quick diagnostic checks (begin here)
1. Look: cracked blades, dents, missing shroud pieces, belt condition.
2. Wiggle test: with engine OFF, try to move fan or pulley by hand. There should be minimal sideways play. Rough feel = worn bearings.
3. Spin test: with engine OFF, spin the fan/pulley—should spin freely and smoothly. Grinding = bad bearing.
4. Belt check: inspect for glazing, cracks, and correct tension (see tension below).
5. Run test (careful): start engine and watch fan action from a safe distance. At idle and low revs the fan should rotate without wobble or knocking. Listen for grinding or knocking from the front end.
6. Radiator airflow: with engine idling and operating temp reached, hold a shop towel a few inches in front of the radiator to feel airflow (keep away from moving fan). Little/no airflow suggests fan or shroud issue.

How to remove and replace the fan assembly (step‑by‑step, beginner friendly)
Safety first: work with engine cool, key off, battery negative disconnected if you’ll be working near belts or electrical. Don’t remove the radiator cap while hot.

1. Prep:
- Park on level ground, set parking brake, chock wheels.
- Let engine cool fully.
- Remove any sheet metal or grill that blocks access to the fan.

2. Note belt routing:
- Before loosening anything, trace and photograph the belt routing so you can fit the belt correctly afterwards.

3. Relieve belt tension and remove belt:
- Loosen the belt tensioner or the alternator/generator mounting bolts to remove tension. Slide belt off the fan pulley. If belt is seized or stuck, soak with penetrating oil and use care.

4. Secure the fan:
- The fan assembly can be heavy. Support it with one hand or a block of wood before removing the hub nut(s).
- Apply penetrating oil to the central nut and studs if corroded.

5. Remove central nut(s) / bolts:
- Unscrew the central nut that holds the fan to the hub. On some MF35 setups the fan is bolted to the water pump—there may be several bolts through the fan into the hub/pump face.
- If the nut is tight, use a breaker bar; hold the fan stationary while loosening. Use a strap wrench or wood block; never jam a screwdriver between blades and the radiator.

6. Pull the fan:
- If the fan won’t pull off, use a fan puller/gear puller to press it off the hub evenly. Never pry on blades—use a proper puller to avoid damage.
- Inspect the mating surfaces for rust or scoring.

7. Inspect the water pump shaft and bearings:
- With fan off, spin the pump pulley by hand. If it’s rough or has excessive play, replace the water pump (see below).
- Inspect the seal for leaks. Coolant residue at the shaft means seal failure.

8. Fit new fan or re‑fit old after repair:
- Clean mating surface, use anti‑seize lightly on threads if desired (check manual), position fan correctly and fit bolts/nut.
- Tighten nuts/bolts gradually and evenly. If you have no torque spec, tighten securely but don’t over‑stretch studs—consult manual if possible.

9. Reinstall belt:
- Refit the belt, set tension. Typical belt tension: about 1/2" (12 mm) of deflection at midpoint with moderate thumb pressure for a single V‑belt. Too tight stresses bearings; too loose slips and overheats.
- Re‑tighten alternator/generator mounts and set belt tension properly.

10. Replace shroud and guards:
- Reinstall shroud so it sits about even with the fan perimeter and directs airflow into the radiator. Shroud should not touch blades—leave small clearance.

11. Start and test:
- Reconnect battery, start engine, let reach operating temp. Check for unusual vibration, leaks, and that airflow is present across the radiator. Re‑check belt tension after a short test run.

Replacing the water pump (bearings/seal failure)
1. Drain coolant into pan (open drain cock or remove lower hose).
2. Remove belt(s), fan (as above), and hoses from the water pump.
3. Unbolt the pump from the timing cover or block (keep track of bolts).
4. Remove pump, clean mating surface, fit new gasket and new pump. Replace any O‑rings or seals as recommended.
5. Reassemble, refill coolant, bleed air (see below), and test.

Bleeding air from system (simple method)
- Fill radiator to neck, fill overflow bottle if fitted.
- Start engine with radiator cap off, idle. As engine warms, thermostat opens and air will bubble out—top up as needed.
- When a steady stream of coolant (no bubbles) flows and temperature stabilizes, fit cap.
- Recheck after a short run and again after the first hour of operation.

Troubleshooting table (symptom -> likely cause -> quick fix)
- Engine overheats only when idling -> fan not moving enough, shroud missing, belt slipping -> inspect fan, shroud, belt tension.
- Overheats at all speeds -> coolant flow problem (thermostat stuck closed, water pump seized, clogged radiator) -> check thermostat, pump, radiator.
- Loud grinding from front -> water pump bearing failing -> replace water pump.
- Vibration after fan service -> fan wobble or imbalance -> check bolt tightness, bent blade, hub alignment.
- Coolant leak near pump shaft -> failed pump seal -> replace pump.

Maintenance tips to avoid future failures
- Replace V‑belt at the first sign of glazing/cracks. Proper tension is key.
- Keep the shroud in place—don’t run without it.
- Flush coolant per recommended schedule and use correct mixture (usually 50/50 antifreeze/water unless manual says otherwise).
- Inspect fan and hub every 100–200 hours or seasonally.
- Straighten radiator fins with a fin comb; keep the core free of debris.
- Replace thermostat every few years if you see temperature inconsistencies.

Safety reminders (don’t skip)
- Work with the engine cold.
- Disconnect battery if working around belts or electrical parts.
- Keep fingers, rags, tools away from rotating fan when engine running.
- Use the right puller for stuck fans; prying can break blades and injure you.

Final notes
- The MF35 uses a straightforward mechanical arrangement; most fan failures are belt, shroud, fan blade/hub, or water‑pump bearing issues. Diagnose by visual inspection and by spinning the pulley/fan by hand.
- If the water pump is bad, replace it—running with a failed pump risks rapid, catastrophic overheating.
- If anything is unclear during the job, consult a service manual for the MF35 for exact bolt patterns and torque settings.

That’s the complete practical overview and repair pathway for the MF35 cooling fan system. Follow the steps, respect safety warnings, and replace bearings/pump if you find roughness or play.
rteeqp73