Manual Transmission Symptom Diagnosis

Condition	Possible Cause	Action
Gear slipping out of mesh	Worn shift fork shaft	Replace .
	Worn shift fork or synchronizer sleeve	Replace .
	Weak or damaged locating spring	Replace .
	Worn bearings on input shaft, countershaft or output shaft	Replace .
	Worn chamfered tooth on sleeve or gear	Replace sleeve and gear .
	Missing or disengagement of snap ring(s)	Install or replace .
Gears refusing to disengage	Weakened or broken synchronizer spring	Replace .
Gears refusing to disengage	Distorted shift shaft or shift fork	Replace .
Hard shifting	Improper clutch pedal free travel	Replace pedal arm and/or clutch master cylinder .
	Distorted or broken clutch disc	Replace .
	Damaged clutch pressure plate	Replace clutch cover .
	Air in clutch hydraulic system	Bleed air .
	Fluid leakage from clutch fluid line	Locate leaking point and repair .
	Worn synchronizer ring	Replace .
	Worn chamfered tooth on sleeve or gear	Replace sleeve and gear .
	Distorted shift shaft	Replace .
Noise	Inadequate or insufficient lubricant	Replenish .
	Damaged or worn bearing(s)	Replace .
	Damaged or worn gear(s)	Replace .
	Damaged or worn synchronizer ring	Replace .
	Damaged or worn chamfered tooth on sleeve or gear	Replace .