Replacing the manual transmission or clutch assembly on a Honda B-series engine requires careful attention to detail and adherence to proper service procedures. This guide provides a general overview of the steps involved, applicable to various Honda and Acura models equipped with B-series engines and manual transmissions.

Important

Always consult the specific factory service manual (FSM) for your vehicle's year, make, and model for precise torque specifications, fluid capacities, and detailed procedural steps. This article serves as a general reference.

1. Safety First#

Prioritizing safety is paramount when working with heavy components like transmissions and when working under a vehicle.

• Secure the Vehicle: Use a sturdy lift or jack stands on a level, stable surface. Never rely solely on a jack.
• Disconnect Battery: Disconnect the negative battery terminal to prevent accidental electrical shorts.
• Personal Protective Equipment (PPE): Wear safety glasses, gloves, and appropriate work attire.
• Support Engine: The engine must be properly supported once the transmission is removed, as the transmission provides a significant mounting point.

2. Tools and Materials#

Gathering the necessary tools and replacement parts before beginning the job will streamline the process.

2.1 Essential Tools#

• Socket and wrench set (metric)
• Torque wrench (capable of various ranges)
• Floor jack and jack stands
• Transmission jack (highly recommended for safety and ease)
• Engine support bar or engine hoist
• Pry bars
• Drain pans
• Fluid pump (for refilling transmission fluid)
• Clutch alignment tool
• Wire brush and brake cleaner
• Bleeder wrench for clutch slave cylinder

2.2 Replacement Parts and Fluids#

• New clutch kit (clutch disc, pressure plate, release bearing, pilot bearing)
• New flywheel (or resurface existing one)
• Transmission fluid (confirm type and capacity with FSM)
• Clutch fluid (DOT 3 or DOT 4 brake fluid, confirm with FSM)
• New axle nuts
• New cotter pins (for lower ball joints, if applicable)
• Optional: New axle seals, shift linkage bushings, slave cylinder, master cylinder

3. Transmission Removal Procedure#

This section outlines the typical steps for removing the manual transmission.

3.1 Vehicle Preparation#

1. Lift and Secure: Raise the vehicle to a comfortable working height and secure it on jack stands.
2. Drain Fluids: Place a drain pan under the transmission and remove the drain plug to drain the transmission fluid. Replace the drain plug once empty.
3. Remove Wheels: Remove both front wheels.
4. Disconnect Battery: Disconnect the negative terminal from the battery.

3.2 Under-Hood Disassembly#

1. Air Intake System: Remove the air intake box, ducting, and any associated components to gain access to the top of the transmission.
2. Shift Cables: Disconnect the shift cables from the shift selector on top of the transmission. Note their orientation for reinstallation.
3. Clutch Slave Cylinder: Disconnect the hydraulic line from the clutch slave cylinder and remove the slave cylinder from the transmission. Be prepared for fluid to leak.
4. Speed Sensor: Disconnect the electrical connector for the vehicle speed sensor (VSS).
5. Starter Motor: Disconnect the electrical connections to the starter motor and remove the starter mounting bolts. The starter may need to be fully removed or simply moved aside.
6. Ground Wires: Disconnect any ground wires attached to the transmission housing.

3.3 Under-Car Disassembly#

1. Axle Nuts: Remove the cotter pins and loosen the large axle nuts on both front axles. These can be very tight and may require a breaker bar.
2. Lower Ball Joints: Separate the lower ball joints from the lower control arms. This typically involves removing a cotter pin and nut, then using a ball joint separator tool. This allows the knuckle to swing out, providing clearance for axle removal.
3. Axle Removal: Carefully pull the axles out of the transmission. Be gentle to avoid damaging the axle seals. Support the outer ends of the axles to prevent damage to the CV joints.
4. Engine Support: Install an engine support bar across the engine bay or position an engine hoist to support the engine from above. Alternatively, use a jack with a wood block under the oil pan, being careful not to damage the pan.
5. Transmission Mounts: Remove the bolts securing the transmission mounts to the chassis. There are typically three main mounts: front, rear, and side.
6. Transmission Housing Bolts: Remove all bolts connecting the transmission housing to the engine block. Note the length and location of each bolt, as they can vary.

Caution

Ensure the engine is securely supported before removing the transmission mounting bolts. Failure to do so can result in engine or vehicle damage, or serious injury.

3.4 Separating Transmission from Engine#

1. Position Transmission Jack: Carefully position a transmission jack under the transmission, ensuring it is stable and balanced.
2. Separate Housing: Gently pry the transmission away from the engine block. It may require some wiggling and careful manipulation. Ensure no wires or hoses are still connected.
3. Lower Transmission: Once separated, slowly lower the transmission using the transmission jack. Guide it carefully to avoid hitting other components.

4. Clutch Inspection and Replacement#

With the transmission removed, the clutch components are accessible for inspection and replacement.

1. Remove Pressure Plate: Unbolt the pressure plate from the flywheel. The clutch disc will then be free.
2. Inspect Flywheel: Examine the flywheel surface for excessive wear, hot spots, cracks, or grooves. It is highly recommended to either resurface the flywheel or replace it with a new one. A damaged flywheel can cause clutch chatter or premature wear.
3. Remove Pilot Bearing: Carefully remove the old pilot bearing from the crankshaft. This often requires a specialized pilot bearing puller.
4. Remove Release Bearing: Remove the old release bearing (also known as the throw-out bearing) from the transmission's input shaft sleeve or clutch fork.
5. Install New Pilot Bearing: Install the new pilot bearing into the crankshaft. Use an appropriate driver to seat it flush.
6. Install New Clutch Disc and Pressure Plate: Using a clutch alignment tool, center the new clutch disc against the flywheel. Install the new pressure plate over the clutch disc and bolt it to the flywheel. Tighten the bolts gradually in a star pattern to the factory specified torque. Remove the alignment tool.
7. Install New Release Bearing: Install the new release bearing onto the transmission's input shaft sleeve or clutch fork, ensuring it moves freely.

Tip

Lightly grease the input shaft splines and the clutch fork pivot points with a high-temperature grease to ensure smooth operation.

5. Transmission Installation Procedure#

Installation is essentially the reverse of removal.

1. Position Transmission: Carefully lift the transmission into position using the transmission jack. Align the input shaft with the clutch disc and pilot bearing.
2. Mate Transmission to Engine: Gently push the transmission onto the engine block. It should slide on smoothly once the input shaft splines align with the clutch disc. Do not force it; if it doesn't slide, rotate the input shaft slightly or re-check clutch alignment.
3. Install Housing Bolts: Install all transmission housing bolts, ensuring they are in their correct locations. Tighten them to the factory specified torque in the recommended sequence.
4. Install Transmission Mounts: Reinstall the transmission mounts and tighten them to the factory specified torque.
5. Reinstall Starter: Reinstall the starter motor and reconnect its electrical connections.
6. Reinstall Axles: Carefully insert the axles into the transmission, ensuring they are fully seated. Reconnect the lower ball joints and tighten their nuts to the factory specified torque, installing new cotter pins.
7. Install Axle Nuts: Install the large axle nuts and tighten them to the factory specified torque, installing new cotter pins.
8. Reconnect Under-Hood Components: Reconnect the shift cables, clutch slave cylinder, VSS connector, and any ground wires.
9. Reinstall Air Intake: Reinstall the air intake system and any other components removed from the engine bay.

6. Post-Installation Checks and Fluid Refill#

After the transmission is installed, perform these critical steps before driving.

1. Refill Transmission Fluid: Fill the transmission with the specified type and amount of fluid through the fill plug. Confirm the level using the dipstick or by filling until fluid begins to seep from the fill hole (depending on transmission design).
2. Bleed Clutch System: Bleed the clutch hydraulic system to remove any air. This typically involves pumping the clutch pedal and opening the bleeder screw on the slave cylinder until no air bubbles are present in the fluid.
3. Reconnect Battery: Reconnect the negative battery terminal.
4. Initial Checks: Start the engine and check for any leaks. Test the clutch pedal for proper feel and engagement. Ensure all gears can be selected smoothly with the engine off and running.
5. Test Drive: Perform a cautious test drive in a safe area, paying attention to clutch engagement, shifting feel, and any unusual noises or vibrations.

Warning

Do not operate the vehicle if the clutch pedal feels spongy or if gears are difficult to engage. Re-bleed the clutch system immediately.