Tools & gear
- Clear flexible hose (3/8–1/2" ID), ~1–2 m
- Small clear plastic bottle (for bubble test) or graduated container
- Hose clamps or good-fitting rubber plug/seal for oil filler or dipstick tube
- Compression tester and/or leak-down tester with adapter for MF35 injector/glow-plug hole (recommended)
- Basic hand tools to remove injector/glow plug or oil filler/dipstick (sockets, screwdrivers, pliers)
- Shop rags, catch pan, degreaser
- PPE: safety glasses, gloves, hearing protection, respirator if working in confined area
- Fire extinguisher nearby

Safety first
- Work outdoors or in a well-ventilated area (diesel fumes/CO). Never run engine in an enclosed space.
- Keep hands/clothing away from moving parts (fan, belts, PTO).
- Engine and exhaust will be hot — avoid burns.
- Secure tractor (park brake on, wheels chocked).
- If you remove injectors/glow plugs, be careful with high-pressure fuel lines — relieve fuel system pressure first and keep fire risk minimal.

Two practical methods to check blow-by on an MF35
Method A — Quick “bubble” crankcase blow-by check (simple, no special gauge)
1. Warm engine to normal operating temperature (15–20 min). Blow-by is best checked warm.
2. Park tractor, set brake, chock wheels.
3. Locate oil filler or dipstick tube. On MF35 you’ll typically use the oil filler (or dipstick tube if the filler is not easily sealed).
4. Fit one end of the clear hose into the oil filler or dipstick tube. Seal the tube/hose joint with a good-fitting rubber plug or clamp so the hose is the only vent path.
5. Put the other hose end into the clear bottle partially filled with water (or a clear container). Bottle opening should be below water level so escaping crankcase gases bubble through.
6. Start the engine and idle it. Observe the bottle:
- Occasional small bubbles = normal.
- Continuous steady bubbling or a strong stream = excessive blow-by (worn rings/bores or valve problems).
7. Rev engine gently and observe changes. More blow-by under load is expected; heavy blow-by at idle is a clear sign of trouble.
8. Shut engine off, remove hose, reinstall cap/dipstick, clean up.

How the simple tool works: the hose routes crankcase vent gasses into water so you can visually see air escaping. It shows presence & relative volume of blow-by but does not quantify which cylinder or exact leakage path.

Method B — Proper diagnosis with compression and leak-down tests (recommended for accurate diagnosis)
A. Compression test (tells you if cylinder sealing/compression is low)
1. Warm engine to operating temp.
2. Remove air cleaner so engine can crank/idle normally.
3. Disable fuel/ignition per engine type (on diesel MF35 remove fuel to injectors or shut shut-off to prevent starting; on petrol remove spark).
4. Fit compression tester into each glow plug/spark plug hole in turn (use correct adapter).
5. Crank the engine with starter several seconds, record max compression per cylinder.
6. Compare cylinders: a consistent reading across cylinders is good. A low cylinder (15% or more lower than the average) indicates ring, valve, or head gasket problem and likely source of blow-by.

B. Leak-down test (pinpoints where compression is escaping)
1. With the engine at TDC for the cylinder being tested, connect the leak-down tester to the injector/glow-plug hole.
2. Supply regulated compressed air (usually ~100 psi) to the tester.
3. The tester gives a % leakage reading: low % = good sealing; high % = bad.
4. To locate leak path, listen/inspect while pressurized:
- Air escaping from dipstick/oil filler = piston rings/crankcase (blow-by).
- Air escaping from intake = intake valve leak.
- Air escaping from exhaust = exhaust valve leak.
- Air bubbling in radiator or coolant tank = head gasket leak.
5. Repeat for each cylinder and compare.

How the leak-down/compression tools are used: compression tester measures peak cranking pressure. Leak-down tester introduces air into the cylinder at TDC and quantifies percent leakage while you observe escape points to identify where compression is lost.

Interpretation / thresholds (general guidance)
- Bubble test: steady strong bubbling at idle = excessive blow-by. Small/occasional bubbles can be normal.
- Compression test: cylinders should be very similar; one cylinder >10–15% low vs others indicates problem.
- Leak-down: typical acceptable leakage is low (single-digit to low teens %). >20–25% is cause for internal inspection (rings/valves/head gasket).

Common causes and replacement parts
- Worn piston rings or cylinder bore wear → piston rings, pistons or cylinder re-bore and over-sized pistons.
- Worn valve seats/guides or burned valves → valves, valve seats, valve stem seals.
- Blown head gasket or cracked head → head gasket, cylinder head service.
- Faulty breather/PCV hose or oil filler cap → breather assembly, hose, oil cap/dipstick (cheap and easy to replace).
- Clogged crankcase ventilation forcing pressure into seals → clean/replace breather and hoses.

Common pitfalls and how to avoid them
- Testing cold engine — warms up first to get realistic blow-by.
- Not sealing the test connection — leaks at the seal give false low readings.
- Running engine in enclosed space — CO hazard.
- Blocking vents completely during test (never seal crankcase without a controlled vent or you'll build pressure and may cause damage).
- Misinterpreting bubble test — it’s qualitative; use compression/leak-down to confirm.
- Removing injectors/fuel lines and not reassembling or contaminating the system — keep parts clean and torque to spec.
- Using incorrect adapter sizes for compression/leak-down; can give false readings.

Typical next steps if excessive blow-by is confirmed
1. Check and renew breather/venting parts (inexpensive, often fixes minor symptoms).
2. Perform compression and leak-down tests to identify cylinder(s) at fault.
3. If rings/bores worn: plan for piston ring replacement, cylinder hone or re-bore and oversize pistons as needed.
4. If valves leaking: remove head, inspect/seat or replace valves and seats.
5. If head gasket failure: replace head gasket and check for head/cylinder warpage.

Final notes
- Start with the simple bubble test to confirm presence of blow-by, then use compression/leak-down to locate the fault.
- For an MF35, routine maintenance of the crankcase breather and correct routing of the breather tube to the air cleaner often prevents crankcase pressure issues.
- If internal engine work is required (rings, bore, valves, head gasket), expect a teardown and parts replacement; get service manual specs for torque and clearances.

No further questions.
rteeqp73

### Overview of Manual Transmission Repair on a Massey Ferguson MF35 Tractor

#### Theory Behind Repair

Manual transmissions convert engine power into movement using gears, allowing the operator to select different speeds and torque levels. The Massey Ferguson MF35 uses a simple yet effective design, relying on a series of gears, shafts, and synchronizers to shift between different speeds. Repair is necessary when components wear out, fail, or become misaligned, which can lead to issues like slipping gears, difficulty shifting, or complete transmission failure.

### Components of a Manual Transmission

1. **Transmission Case**: The outer shell that houses all internal components.
2. **Input Shaft**: Connected to the engine, it transfers power into the transmission.
3. **Output Shaft**: Connects to the drive shaft and transfers power to the wheels.
4. **Gears**: Different sizes that allow for speed variations. There are usually multiple gears for different speed ranges (low, high, reverse).
5. **Synchronizers**: Help match the speeds of gears during shifting to enable smooth transitions.
6. **Shift Forks**: Move the gears into position when shifting.
7. **Shift Rods**: Linkages that connect the gear shifter to the shift forks.
8. **Bearings**: Keep the shafts in position and reduce friction.

### Common Issues

1. **Worn Gears**: Can lead to slipping or grinding noises.
2. **Failed Synchronizers**: Causes hard shifting or grinding during shifts.
3. **Faulty Bearings**: Can result in excessive play, noise, or difficulty in shifting.
4. **Misaligned Shift Rods**: Can create issues with engaging the correct gear.

### Tools Needed

- Socket set
- Wrench set
- Screwdriver set
- Pliers
- Torque wrench
- Gear oil
- Clean rags
- Transmission jack or hoist
- Service manual for MF35

### Step-by-Step Repair Process

#### 1. **Preparation**

- **Safety First**: Ensure the tractor is on a flat surface with the parking brake engaged. Disconnect the battery to prevent electrical issues.
- **Drain the Fluid**: Remove the drain plug from the transmission case to let out old gear oil. This can be messy, so have a pan ready.

#### 2. **Remove the Transmission**

- **Detach Linkages**: Use the socket and wrench to disconnect the shift rods from the transmission.
- **Disconnect Driveshaft**: Remove the bolts holding the driveshaft to the output shaft.
- **Unbolt Transmission**: Use the socket set to remove the bolts securing the transmission to the tractor frame.
- **Use a Jack**: Support the transmission with a transmission jack. Carefully lift and remove the transmission from the tractor.

#### 3. **Disassemble the Transmission**

- **Remove the Case**: Unscrew the bolts on the transmission case and carefully lift the top half off to expose internal components.
- **Inspect Components**: Take note of the condition of gears, bearings, and synchronizers. Look for signs of wear, pitting, or damage.

#### 4. **Replace Worn Parts**

- **Gears and Synchronizers**: If any gears or synchronizers are worn, replace them. Remove the old parts by unscrewing any retaining bolts or clips.
- **Bearings**: Check all bearings and replace any that show excessive wear or roughness. Use a bearing puller if necessary.

#### 5. **Reassemble the Transmission**

- **Clean Surfaces**: Ensure all mating surfaces are clean. Remove old gasket material and debris.
- **Install New Parts**: Begin reassembling the transmission by installing new gears and synchronizers. Ensure they are seated correctly.
- **Reattach the Case**: Place the top half of the transmission case back on and secure with bolts, following the recommended torque specifications from the service manual.

#### 6. **Reinstall the Transmission**

- **Position the Transmission**: Use the jack to lift the transmission back into position on the tractor frame.
- **Bolt Down**: Secure the transmission with bolts to the frame, ensuring everything is aligned.
- **Reconnect Driveshaft and Linkages**: Reattach the driveshaft and linkages, ensuring everything is properly secured.

#### 7. **Refill with Gear Oil**

- **Add New Oil**: Replace the drain plug and refill the transmission with the appropriate gear oil as specified in the service manual.

#### 8. **Final Checks**

- **Reconnect Battery**: Reattach the battery and check connections.
- **Test Shift**: Start the tractor and test the transmission by shifting through all gears while stationary.

### Conclusion

Manual transmission repair on a Massey Ferguson MF35 requires careful attention to detail and an understanding of how the components work together. By following these steps and understanding what can go wrong, you can perform maintenance and repairs effectively. Always refer to the service manual for specific torque specifications and part numbers.
rteeqp73

To understand the theory behind shifting drum repair on a Massey Ferguson MF35 tractor, we need to first grasp the function of the shifting mechanism and the role of the shifting drum in the transmission system.

### Theory Overview

1. **Function of the Shifting Drum**:
- The shifting drum is part of the tractor's transmission system, which allows the operator to select different gears. It is coupled with the gear selector forks that engage the gears in the gearbox.
- The drum has grooves or notches that align with the gear selector forks to facilitate smooth gear changes.

2. **Common Faults**:
- **Wear and Tear**: Over time, the shifting drum can wear out, leading to difficulty in shifting gears or slipping out of gear.
- **Misalignment**: The drum may become misaligned due to improper installation or damage, causing ineffective engagement of the gears.
- **Damage**: Cracks or breaks in the drum can prevent it from functioning correctly, leading to a complete failure in gear shifting.

### Repair Process

1. **Diagnosis**:
- Identify the issue, whether it’s difficulty in shifting, grinding noise, or inability to stay in gear. This helps in determining if the drum needs repair or replacement.

2. **Disassembly**:
- Remove the transmission cover and other components to access the shifting drum. This allows for inspection and repair without obstruction.

3. **Inspection**:
- Examine the shifting drum for wear, cracks, or misalignment. Check the grooves for signs of rounding or damage. This determines the extent of the repair needed.

4. **Repair Options**:
- **If Worn**: If the drum is worn but not severely damaged, it can often be machined to restore its original shape and functionality.
- **If Misaligned**: Adjust or realign the drum to ensure proper engagement with the gear selector forks.
- **If Damaged**: If there are cracks or significant damage, replacing the drum is necessary to restore functionality.

5. **Reassembly**:
- Once repaired or replaced, reassemble the transmission components in reverse order. Ensure all parts are clean and lubricated as necessary.

6. **Testing**:
- After reassembly, perform a functionality test to ensure that gear shifting is smooth and that the tractor operates correctly in all gears.

### Conclusion

Repairing the shifting drum on a Massey Ferguson MF35 tractor addresses the root causes of shifting issues by restoring the mechanical integrity of the component. This, in turn, ensures that the tractor can shift gears reliably, enhancing its overall performance and usability. Understanding the theory behind the shifting mechanism allows for more effective troubleshooting and repairs.
rteeqp73

**Theory of Gearbox Planetary Gear Replacement on a Massey Ferguson MF35 Tractor**

1. **Understanding the Gearbox Function**:
The gearbox in a tractor like the Massey Ferguson MF35 is responsible for transmitting power from the engine to the wheels. The planetary gear system allows for various gear ratios, providing torque and speed adjustments essential for different operating conditions.

2. **Identifying the Fault**:
Common issues with the planetary gear system may include excessive wear, broken gears, or bearing failure. These faults can lead to noisy operation, slipping gears, or complete loss of drive.

3. **Disassembly Process**:
- **Safety First**: Ensure the tractor is turned off, and take precautions to prevent accidental movement.
- **Remove the Gearbox Cover**: This typically involves unscrewing bolts and carefully lifting off the cover to expose the internal components.
- **Drain Oil**: Before further disassembly, drain the oil to prevent spills and ensure a clean working environment.

4. **Removing the Planetary Gear Assembly**:
- Disconnect any linkages or components attached to the planetary gear assembly.
- Carefully remove the assembly from the gearbox housing. This may involve unbolting and lifting it out, ensuring you note the orientation and order of components for reassembly.

5. **Inspecting Components**:
- Examine the planetary gears, sun gear, ring gear, and bearings for signs of wear or damage. Identifying the source of the fault is critical for ensuring a successful repair.

6. **Replacement of Faulty Parts**:
- Replace any damaged or worn gears with new components. This restores the integrity of the gear system, allowing for proper meshing and operation.
- Replace bearings if they show signs of wear, as they are crucial for smooth rotation and load distribution.

7. **Reassembly Process**:
- Reinstall the planetary gear assembly, ensuring all components are aligned correctly.
- Reattach linkages and any other components that were removed, ensuring they are securely fastened.

8. **Testing**:
- After reassembly, fill the gearbox with the appropriate oil and run the tractor to ensure the planetary gear system operates smoothly without noise or slipping.
- Monitor for any unusual sounds or behaviors that may indicate improper installation or residual issues.

9. **Final Check**:
- After a test run, check for leaks and ensure all components are functioning correctly. This final inspection helps confirm that the replacement has resolved the initial fault.

**Conclusion**:
Replacing the planetary gears in the Massey Ferguson MF35 gearbox restores functionality by eliminating wear or damage that could disrupt power transmission. The repair ensures that the gears mesh properly, allowing for efficient torque and speed control, essential for the tractor's performance.
rteeqp73