Ford Mustang (1999-2004) Service Manual: Manual Transmission and Clutch (Diagnosis and Testing)

Inspection and Verification

It is important to get an accurate description of the concern before any diagnosis can be carried out.

Ask questions as to whether it occurs when hot or cold, during shifting, driving at a particular speed or in a particular gear. If possible, have the customer demonstrate the concern.

With the vehicle at a complete stop, shift through all the gears and evaluate the noise at different engine rpm. Check for any noises in NEUTRAL at different engine rpm.

Symptom Chart

Condition	Possible Sources	Action
Clutch slippage	Clutch pedal sticking. Pressure plate diaphragm spring damaged or weakened. Clutch pressure plate damaged. Clutch disc facing damaged or worn excessively. Clutch disc facing surface hardened or oilcoated. Clutch release hub and bearing binding. Flywheel glazed or damaged. loose pressure plate to flywheel bolts	Go To Pinpoint Test A .
Clutch chatter or shudder	Loose or worn engine mount. Loose pressure plate to flywheel bolts Oil on clutch disc facing. Clutch pressure plate damaged or excessive runout. Clutch disc facing surface hardened or damaged. Flywheel surface glazed or damaged. Transmission input shaft eccentric or not perpendicular.	Go To Pinpoint Test B .
Clutch drag	Clutch drag. Cable release linkage outside the flywheel housing worn, cracked, bent. Excessive runout or damaged clutch disc. Clutch disc splines rusted or worn. Loose pressure plate to flywheel bolts.	Go To Pinpoint Test C .
Clutch pedal pulsation	Clutch disc damaged or worn. Excessive flywheel runout. Loose pressure plate to flywheel bolts. Improperly assembled release lever to pivot stud.	Go To Pinpoint Test D .
Clutch related vibrations	Engine component grounding against frame. Loose flywheel bolts. Excessive flywheel runout. Imbalanced clutch pressure plate. Accessory drive belt loose or damaged.	Go To Pinpoint Test E .
Hard shifting	Manual transmission concern. Loose pressure plate to flywheel bolts.	Go To Pinpoint Test F .
Excessive noise	Pilot bearing worn or damaged. Excessive crankshaft end play.	Go To Pinpoint Test G .
Transmission difficult to shift	Lubricant. Internal shift mechanism. Sliding gears, synchronizers Housings, shaft. Loose pressure plate to flywheel bolts.	ADD or DRAIN AND FILL with specified lubricant. CHECK the internal shift mechanism for smooth operation. REPAIR or INSTALL a new mechanism as necessary. CHECK for free movement of gears and synchronizers. REPAIR or INSTALL new components as necessary. CHECK for binding condition between the input shaft and the engine crankshaft pilot bearing or bushing. REPAIR or INSTALL new components as necessary. CHECK for loose bolts at the pressure plate. INSTALL new components as necessary
NOTE: While verifying the condition, determine whether the noise is gear rollover noise, release bearing rub or some other transmissionrelated noise. Gear rollover noise, inherent in manual transmissions, is caused by the constant mesh gears turning at the engine idle speed while the clutch is engaged and the transmission is in NEUTRAL. Release bearing rub is sometimes mistaken for mainshaft bearing noise. Gear rollover noise will disappear when the clutch is disengaged or when the transmission is engaged in gear. Release bearing rub will disappear when the clutch is engaged. In the event that a bearing is damaged, the noise is more pronounced while engaged in gear under load or coast than in NEUTRAL. Noisy in forward gears	Lubricant. Components grounding out on the transmission. Components housing bolts Bearings or gears.	ADD or DRAIN AND FILL with specified lubricant CHECK for screws, bolts, etc., of body or other components grounding out. CORRECT as necessary. CHECK the torque on the transmission-toflywheel housing bolts and the flywheel housing-to-engine block bolts. TIGHTEN the bolts to specification. INSPECT the bearings. INSPECT the gears and gear teeth for wear or damage. INSTALL new components as necessary.
Gears clash when shifting from one forward gear to another	Pilot bearing. Gear teeth and/or synchronizer. Engine idle speed too high.	CHECK for a binding condition between the input shaft and the engine crankshaft pilot bearing. INSTALL new components as necessary REPAIR or INSTALL new components as necessary REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual
Transmission jumps out of gear	Transmission range selector lever boot Transmission-toengine mounting bolts Crankshaft pilot bearing. Internal damage. Gear teeth.	INSTALL a new boot if exceptionally stiff. TIGHTEN the bolts to specification. INSTALL a new bearing INSPECT the synchronizer sleeves for free movement on their hubs. INSPECT the synchronizer blocking rings for widened index slots, rounded clutch teeth and smooth internal surface. CHECK countershaft cluster gear for excessive end play. CHECK shift forks for worn or loose mounting on shift rails. INSPECT the synchronizer sliding sleeve and the gear clutch teeth for wear or damage. REPAIR or INSTALL a new component as necessary. If worn or damaged, INSTALL new gears
Transmission will not shift into one gear-all others OK	Manual shift linkage. Backup switch ball Internal components.	REPAIR or INSTALL new components as necessary If REVERSE is the problem, CHECK backup switch for ball frozen in extended position. INSPECT the shift rail and fork system, synchronizer system and the gear clutch teeth for restricted travel. REPAIR or INSTALL new components as necessary
Transmission is locked in one gear and cannot be shifted out of that gear	Internal components Fork on rail.	INSPECT the problem gears, shift rails, forks and the synchronizer for wear or damage. REPAIR as necessary. CHECK the shift rail interlock system
Transmission leaks	Lubricant Other component leaking False report. Internal components. Fill and drain plugs	CHECK the level and type. IDENTIFY leaking fluid as engine, power steering, or transmission fluid. REPAIR as necessary REMOVE all traces of lube on the exposed transmission surfaces. CHECK the vent for free breathing. OPERATE the transmission and INSPECT for new leakage. REPAIR as necessary INSPECT for leaks at the input shaft bearing retainer seal and the shift rail expansion plug. INSPECT for leaks at the top cover gasket. INSPECT the case for sand holes or cracks. REPAIR or INSTALL a new case as necessary. CHECK fill and drain plugs and bore threads. REPAIR as necessary. TIGHTEN plugs to specified torque value.
Bearing failure	Other part failure. Raceways or rollers. Lubricant. Towing vehicle further than 80 km (50 miles) with driveshaft installed. Mainshaft tapered bearing and needle caged bearings are especially susceptible to damage. Vibration breakup of retainer and brinelling of races. Bearing(s). Shafts or bore. Overloading of vehicle. Incorrect preload. Input shaft oil dam. Oil baffle in the input bearing shim pack.	REMOVE, DISASSEMBLE and CLEAN the transmission. Inspect for damaged parts and install new components as necessary. (Note: RESET the bearing preload if any new tapered bearings are installed). DETERMINE the cause of vibration and CORRECT. Otherwise PROCEED as above. Install new components as necessary and verify the oil dam installation is correct. CHECK for correct installation of the snap ring on the mainshaft next to the oil dam. INSTALL a new oil baffle, making sure it is not damaged during assembly.

Pinpoint Tests

PINPOINT TEST A: CLUTCH SLIPPAGE

Test Step	Result / Action to Take
A1 INSPECT THE CLUTCH LINKAGE	Yes GO to A2 . No INSPECT the clutch pedal
Key in OFF position. Block the wheels and apply the parking brake. Depress and slowly release the clutch pedal. Does the clutch pedal release without binding?	Yes GO to A2 . No INSPECT the clutch pedal
A2 CARRY OUT A STALL TEST	Yes The clutch is not slipping. VERIFY the customer concern. No INSPECT the clutch components for damage.
Key in START position. Block the wheels and apply the parking brake. Place the transmission in fourth gear. Increase the engine speed to 2000 rpm and slowly release the clutch pedal. Does the engine stall within five seconds?

PINPOINT TEST B: CLUTCH CHATTER OR SHUDDER

Test Step	Result / Action to Take
B1 CHECK ENGINE OR TRANSMISSION MOUNTS	Yes TIGHTEN or INSTALL new engine mounts or transmission mounts. TEST the system for normal operation. No GO to B2 .
Inspect all the engine and transmission mounts for looseness or damage. Are any of the engine or transmission mounts loose or damaged?
B2 INSPECT PRESSURE PLATE BOLTS	Yes TIGHTEN or INSTALL new bolts. REFER to Section. TEST the system for normal operation. No GO to B3 .
Inspect the pressure plate-to-flywheel bolts. Are any of the pressure plate-to-flywheel bolts loose?
B3 INSPECT PRESSURE PLATE	Yes INSTALL a new clutch pressure plate. REFER to Section. TEST the system for normal operation. No GO to B4 .
Remove the clutch pressure plate. Refer to Section Inspect the clutch pressure plate. Refer to Pressure Plate Check . Are any signs of damage present on the clutch pressure plate?
B4 CHECK CLUTCH DISC	Yes GO to B5 . No INSTALL a new clutch disc. REFER to Section. TEST the system for normal operation.
Carry out the clutch disc inspection procedure. Refer to Disc Check . Is the clutch disc OK?
B5 INSPECT THE FLYWHEEL	Yes GO to B6 . No REPAIR or INSTALL a new flywheel as necessary. REFER to Section. TEST the system for normal operation
Inspect the flywheel for damage and runout. Refer to Flywheel Runout Check . Is the flywheel OK?
B6 INSPECT THE INPUT SHAFT	Yes INSTALL a new input shaft. No VERIFY the customer concerns. GO to Symptom Chart if necessary.
INSPECT the input shaft for signs of wear or damage. Are any signs of wear or damage present on the input shaft?

PINPOINT TEST C: CLUTCH DRAG

Test Step

Result / Action to Take

C1 CHECK HIGH SHIFTING EFFORTS

Yes

Clutch system OK.

CHECK the clutch pressure plate and clutch disc. INSTALL a new clutch pressure plate or clutch disc if necessary. TEST the system for normal operation

Key in START position.
Set parking brake.
With the shift control selector in REVERSE, clutch disengaged and engine idling, move the shift lever to a position halfway between REVERSE and NEUTRAL.
Slowly engage clutch. The transmission will behave as if it is in NEUTRAL.
Gear clash can now be heard if an attempt is made to shift into REVERSE with the clutch engaged. Reserve can now be measured.
While maintaining light pressure on the shift selector, slowly press the clutch pedal to the floor. The gear clash will stop and the shift selector will slide into the REVERSE position.
Is there a minimum 19.05 mm (0.750 inch) clutch pedal reserve?

PINPOINT TEST D: CLUTCH PEDAL PULSATION

Test Step	Result / Action to Take
D1 CHECK THE CLUTCH PEDAL PULSATION	Yes GO to D2 . No VERIFY customer concern. GO to Symptom Chart if necessary.
Key in START position. With the transmission in NEUTRAL, slowly press the clutch pedal. Does the clutch pedal pulsate while being pressed?
D2 INSPECT PRESSURE PLATE BOLTS	Yes TIGHTEN or INSTALL new bolts. TEST the system for normal operation. No GO to D3 .
Inspect the pressure plate-to-flywheel bolts. Are any of the pressure plate-toflywheel bolts loose?
D3 INSPECT THE CLUTCH PRESSURE PLATE	Yes INSTALL a new clutch pressure plate. TEST the system for normal operation. No GO to D4 .
Remove the clutch pressure plate. INSPECT the clutch pressure plate for damage. Refer to Pressure Plate Check . Are there any signs of damage present on the clutch pressure plate?
D4 INSPECT THE CLUTCH DISC	Yes GO to D5 . No INSTALL a new clutch disc. TEST the system for normal operation.
Carry out the clutch disc inspection procedure. Refer to Disc Check . Is the clutch disc OK?
D5 INSPECT THE FLYWHEEL	Yes GO to D6 . No TIGHTEN, RESURFACE or INSTALL a new flywheel as necessary. TEST the system for normal operation.
Inspect the flywheel for damage and runout. Refer to Flywheel Runout Check . Is flywheel OK?
D6 INSPECT RELEASE LEVER INTERFACE TO PIVOT STUD	Yes INSTALL a new pivot stud and release lever.TEST the system for normal operation. No VERIFY customer concern. GO to Symptom Chart if necessary.
Inspect the release lever and the pivot stud for damage or misalignment. Are there any signs of damage present or misalignment between the release lever and pivot stud?

PINPOINT TEST E: CLUTCH RELATED VIBRATIONS

Test Step	Result / Action to Take
E1 CHECK FOR ENGINE COMPONENT GROUNDING	Yes REPAIR the components as necessary. TEST the system for normal operation. No GO to E2 .
Raise the vehicle on a hoist. Check the engine and transmission mounts for grounding. Check for exhaust manifolds or other engine component grounding on the body or frame. Is there evidence of grounding on the body or frame?
E2 CHECK FOR ACCESSORY DRIVE VIBRATIONS	Yes REFER to Section to diagnose the accessory drive belt components. No STOP the engine and INSTALL the drive belt. GO to E3 .
Key in START position. Remove the accessory drive belt. Does the vibration stop when the accessory drive belt is removed from the engine?
E3 CHECK FOR RELEASE BEARING NOISE	Yes INSTALL a new clutch release hub and bearing. REFER to Section. No GO to E4 .
Key in START position. Depress and hold the clutch pedal. Is a whirring, grating, or grinding noise present only when pedal is pushed?
E4 INSPECT THE FLYWHEEL	Yes VERIFY customer concern. GO to Symptom Chart if necessary. No TIGHTEN, RESURFACE or INSTALL a new flywheel. REFER to Section. TEST the system for normal operation.
Key in OFF position. Remove the transmission. Carry out a flywheel check. Refer to Flywheel Runout Check . Is the flywheel OK?

PINPOINT TEST F: HARD SHIFTING

Test Step	Result / Action to Take
F1 CHECK THE CLUTCH RELEASE CABLE	Yes REPAIR or INSTALL a new clutch release cable as necessary. TEST the system for normal operation. No GO to F2 .
NOTE: Check the upper shift boot for twisting. NOTE: Check the engine idle speed. Inspect the clutch release cable for wear or damage. Make sure the clutch release cable is correctly routed and that all the fasteners are installed. Are there any fasteners missing or is the cable worn, damaged or incorrectly routed?
F2 CHECK THE CLUTCH PEDAL	Yes VERIFY customer concern. TEST the system for normal operation. No GO to F3 .
Loosen the clutch pedal shaft nut. Lift the clutch pedal to the most upward position. While holding the clutch pedal in the most upward position, tighten the nut. Was the clutch pedal incorrectly adjusted?
F3 CHECK THE CLUTCH PEDAL QUADRANT	Yes INSTALL a new quadrant. TEST the system for normal operation. No GO to F4 .
Pull up on the clutch pedal to the upstop. Pulling up on the pedal ensures that the quadrant is free to rotate through it's complete range of motion against the spring load of the quadrant. Is the clutch pedal quadrant binding?
F4 MEASURE THE CLUTCH RESERVE	Yes INSTALL a new pressure plate and clutch disc. REINSTALL the transmission. RECHECK the clutch reserve. TEST the system of normal operation. No GO to F5 .
NOTE: Do not check the clutch system after the road test. Allow the vehicle to cool down before carrying out the clutch reserve check. NOTE: Remove the floor mat, if equipped, to allow the clutch pedal to travel to the downstop. Install a cable tie to the lower clutch pedal, than attach a tape measure to the cable tie. Pull the tape measure up to the steering wheel. Position it through the steering wheel opening. Depress the clutch fully and start the vehicle. Shift the transmission into reverse gear, then move the shift lever forward to the position in between reverse gear and neutral. Slowly release the clutch pedal (if the vehicle creeps rearward, move the shift lever forward a little more). The transmission will behave as if in neutral, but the reverse gear synchronizer will be bypassed. With the clutch pedal up, gently pull the shift lever toward the reverse gear position. Gear clash can now be heard. Slowly depress the clutch pedal. Using the steering wheel inner seam as a reference, note the measurement when the gear clash stops or the shift lever slides into reverse gear. Depress the clutch pedal to the downstop. The difference between the measurement taken when the gear clash stopped and the measurement taken at the downstop is the clutch reserve. Is the clutch reserve less than 19 mm (0.75 inch)?
F5 INSPECT THE RELEASE LEVER AND PIVOT STUD	Yes INSTALL a new release lever or pivot stud as necessary. TEST the system for normal operation. No GO to F6 .
Remove the transmission. Inspect the release lever and the pivot stud for wear, damage or misalignment. Is the release lever or pivot stud worn, damaged or misaligned?
F6 INSPECT THE RELEASE BEARING	Yes INSTALL a new release bearing. TEST the system for normal operation. No GO to F7 .
Inspect the release bearing for wear or damage. Make sure the release lever is seated in the release bearing pocket. Is the release bearing worn or damaged?
F7 INSPECT THE PILOT BEARING	Yes INSTALL a new pilot bearing. TEST the system for normal operation. No GO to F8 .
Inspect the pilot bearing for wear or damage. Is the pilot bearing worn or damaged?
F8 INSPECT THE CLUTCH PRESSURE PLATE TO FLYWHEEL BOLTS	Yes INSTALL a new pressure plate and clutch disc. Note the condition of the removed components (wear, damage or oil contamination). For oil contamination, REPAIR as necessary. TEST the system for normal operation. If the transmission is still hard to shift, GO to F9 . No TIGHTEN the bolts to 80 N·m. TEST the system for normal operation. If the transmission is still hard to shift, GO to F9 .
Measure the clutch pressure plate to flywheel bolts. Is the bolt torque greater than or equal to 65 N·m?
F9 INSPECT THE TRANSMISSION	Yes INSTALL new components or REPAIR as necessary. TEST the system for normal operation. No ASSEMBLE and INSTALL the transmission. TEST the system for normal operation.
Remove the transmission. Disassemble the transmission. Carry out the following: inspect all the shift rails for excessive scuffing or wear. check the interlock pins on the shift rail. make sure the interlock bolts are tighten to 31 N·m. inspect the shift pads for wear or cracking. inspect the shift forks for wear or damage. check the synchronizer rings (of the affected gear[s]) for wear or damage. check the synchronizer hubs (of the affected gear[s]) for wear or damage. inspect the clutching teeth of the affected gear. Are there any internal components worn or damaged?

PINPOINT TEST G: EXCESSIVE NOISE

Test Step	Result / Action to Take
G1 TRANSMISSION NEUTRAL GEAR ROLLOVER TEST	Yes INSPECT the clutch component for damage. REFER to General Procedures in this section. No GO to G2 .
Start the engine and let it idle with the transmission in neutral and the clutch engaged (pedal up). If noise is excessive, depress the clutch pedal to stop the transmission input shaft from rotating. Does the noise stop when the clutch pedal is depressed?
G2 CHECK THE PILOT BEARING	Yes GO to G3 . No INSTALL a new pilot bearing.
Inspect the pilot bearing for damage. Refer to Bearing . Is the pilot bearing OK?	Yes GO to G3 . No INSTALL a new pilot bearing.
G3 CHECK TORSION SPRINGS	Yes GO to G3 . No INSTALL a new pilot bearing. No INSPECT the crankshaft end play.
Inspect the torsion springs for fatigue or breakage. Are there any signs of fatigue or breakage?

Manual Transmission and Clutch (Diagnosis and Testing)