Clutch 3

Understanding Clutch Adjustments
- Adjusting the clutch is crucial for first-year mechanics.
- Measurement specifications for different clutches must be understood and practiced in the shop.
- Important Measurements:
- Half inch clearance between the clutch brake and the release bearing.
- One-eighth inch clearance between the release forks and the release bearing.
Types of Clutches:
- Haldex Clutch:
- Features a locking jam nut and a threaded adjuster instead of an internal adjuster.
- Not commonly seen, but worth knowing.
- Pull-Type Clutch:
- Similar adjustment measurements to standard clutches.
Hydraulic Clutch Systems:
- Maintaining hydraulic systems for clutches involves checking for air in the system.
- Symptoms indicate air in the system when the pedal feels spongy.
- Bleeding the Hydraulic System:
- Similar to bleeding hydraulic brakes.
- Techniques include:
  - Gravity Bleeding: Letting gravity pull fluid through the lines.
  - Annual Bleeding: Holding and pumping the pedal while opening and closing the bleeder.
  - Pressure Bleeding: Forcing fluid up to push the air out.
- Always keep the fluid reservoir full during the process to avoid introducing air back into the system.

Primary Cause of Clutch Failure:
- Heat generated from excessive slipping can lead to loss of friction material and failure.
- Signs of a burnt clutch include a specific burning smell resembling overheated brakes.
- If burnt, assess the flywheel conditions and consider resurfacing it.
Clutch Smearing:
- Refers to the heat damage on the friction disc material.
- Hot spots indicate excessive wear and potential failure points.
Clutch Chatter:
- Described as grabbing and slipping sensations during clutch operation.
- Common causes include:
- Oil-soaked discs (from rear main seal leaks, transmission oil, or grease).
- Warped flywheel or pressure plate.

Driver-Induced Failures:
- Excessive clutch slip during starts, improper gear shifts, and clutch riding on inclines can cause significant wear.
- Examples of Poor Practices:
- Starting in too high of a gear with a load.
- Riding the clutch on inclines instead of fully engaging the brake.
- Coasting in gear with the clutch disengaged, leading to component overspeed.
Clutch Wear & Adjustment:
- The importance of regularly checking and adjusting the clutch to prevent slipping.
- Symptoms of wear indicate the need for adjustments or replacements proficiently pushed by the system variables.
Effects of Binding:
- Binding components or too much pedal travel can fail proper operation of the clutch.
- Checking Components for Binding:
- Ensure proper release bearing clearance.
- Binding linkage can impact performance.

Clutch Diagnostics:
- Noise on Disengagement: Leads to checking the release bearing and pilot bearing for failure.
- Gears Grinding/Shifting Issues: Often indicate free play problems or improper releasing mechanisms.
- Cleaning Discs: If the clutch has oil saturation, replacement is necessary rather than attempting cleaning.
Removing and Replacing a Clutch:
- Key considerations include motor mount locations that may affect transmission removal.
- Important sequence and detail during removal to avoid damage.
Inspection of Components During Replacement:
- Check for loose bolts and wear on the flywheel surface, typically in the 3:00 to 8:00 position due to gravity and torque.
- Look for cross shaft bushing wear and replace as necessary.
Using Dial Indicators:
- Set dial indicators against the flywheel to check for run-out with a maximum allowable of $(0.008)$ inches.
- Too much run-out requires resurfacing the flywheel to prevent engagement issues.

Clutch Assembly:
- Ensure correct positioning of markings on clutch components during assembly to prevent operational failures.
- Torque clutch bolts to OEM specifications, usually around $(55 ext{ ft-lbs})$ for 7/16 bolts, using a crisscross pattern.
Use of Shipping Locks:
- Promote secure assembly of clutches prior to installation.
Environmental Safety:
- Awareness and assessment of fumes and gases in work areas for worker safety.