Clutch Overview; Clutch Service Diagnosis; Clutch Chatter - Jeep 1979 CJ-5 Technical & Service Manual

ZA-1
CLUTC
SECTION INDEX
General Information ZA-1 Clutch Service
Page
ZA-8
G E N E R A L I N F O R M A T I O N
Page
Clutch Adjustments 2A-6
Clutch Component Service 2A-8
Clutch Linkage 2A-6
Page
Clutch Pedal Free Play Adjustment 2A-6
General 2A-1
Service Diagnosis 2A-1
GENERAL
The clutch assembly used in Jeep vehicles consists of a
single dry-disc driven plate and a spring and lever-type
clutch cover (fig. 2A-1).
Two clutch cover styles are used. A 10.5 inch (26.7 cm)
diameter direct spring pressure cover is used in CJ mod-
els with six- or eight-cylinder engines. An 11.0 inch (27.9
cm) diameter semi-centrifugal cover is used on Cherokee
and Truck models with eight-cylinder engine. Cherokee
and Truck models with six-cylinder engine use an 11.0
inch (27.9 cm) direct spring pressure cover.
The two clutch covers are similar in appearance and
construction consisting of a pressure plate, release le-
vers, lever pivots, apply springs, and outer cover.
Both covers apply spring pressure directly against the
pressure plate to maintain engagement. However, the
semi-centrifugal cover also utilizes six rollers, located
between the pressure plate and cover, to exert additional
apply force at higher engine speeds. At these speeds,
centrifugal force moves the rollers outward wedging
them between the cover and pressure plate to increase
apply force.
The driven plate consists of a steel hub with integral
cushion springs and clutch friction material which is
riveted to the hub (fig. 2A-1). The function of the cush-
ion springs is to absorb excessive torque loads and pro-
vide smoother clutch engagement.
The clutch release mechanism consists of a throwout
bearing located on the transmission front bearing cap
and a forked lever mounted on a ball and pivot installed
in the clutch housing. A spring, attached to the lever and
anchored to the ball pivot, is used to maintain lever-to-
pivot ball contact.
Two throwout bearing designs are used (fig. 2A-2).
The bearing used in CJ models is connected to the throw-
out lever by retaining springs riveted to the support and
sleeve portion of the bearing. The bearing used on Cher-
okee and Truck models has a groove machined in the
support and sleeve to accept the throwout lever. A wave
washer is used to retain the lever on the bearing.
SERVICE DIAGNOSIS
Clutch problems can generally be assigned to one of
the following categories defined as:
• Clutch chatter
• Clutch slippage or inadequate clutch pedal free play
• Clutch drag or inadequate clutch release
• Clutch pedal pulsation
• Clutch-related vibration
• Clutch area noises
"Each category is described in common complaint lan-
guage and followed by simplified diagnosis and repair
procedures.
NOTE: Before performing any of the following diag-
nosis and repair procedures, adjust pedal free play and
be sure the clutch pedal returns to the pedal stop
completely.
Clutch Chatter
Clutch chatter can be described as a shaking or shud-
dering sensation felt throughout the vehicle. Chatter