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21 - 2
MANUAL TRANSMISSION
•
TRANSMISSION
IDENTIFICATION
Transmission identification information i s located
on a machined pad a t the r i g h t side of the t r a n s m i s -
sion case (Fig. 1). Information provided includes the
transmission and vehicle identification numbers. Re-
fer t o t h i s information when ordering replacement
parts.
Fig. 2 Transmission Operating Levers
SERVICE DIAGNOSIS
The
majority
of transmission
malfunctions are
caused by insufficient lubricant, incorrect l u b r i c a n t ,
misadjusted linkage, loose m o u n t i n g components, or
improper operation.
HARD
SHIFTING
A l o w l u b r i c a n t level, misadjusted linkage, dam-
aged linkage, or w o r n , damaged i n t e r n a l shift compo-
nents are the most common causes of h a r d s h i f t i n g .
I f h a r d shifting is also accompanied by gear clash,
synchronizer components may be w o r n or damaged.
H a r d s h i f t i n g may also be caused b y insufficient
l u b r i c a t i o n o f linkage components, o r a loose o r mis-
aligned gear shift housing. E i t h e r f a u l t can r e s u l t i n
linkage b i n d and h i g h shift efforts.
NOISY
OPERATION
Transmission noise is most often a result o f w o r n
or damaged components.
Chipped, b r o k e n gear or
synchronizer teeth and b r i n n e l l e d , spalled bearings
a l l cause noise. A b n o r m a l wear a n d damage t o inter-
n a l components is frequently the end result o f insuf-
ficient
l u b r i c a n t , non-recommended lubricants, or
improper operation.
SLIPS
OUT OF GEAR
Transmission
disengagement m a y be caused b y
misadjusted or damaged linkage, o r w o r n synchro-
nizer c l u t c h teeth on the m a i n s h a f t gears. Incorrect
assembly w i l l also contribute to gear disengagement.
LOW LUBRICANT
LEVEL
Insufficient transmission l u b r i c a n t i s u s u a l l y t h e
result o f leaks, or inaccurate f l u i d level check or re-
fill method. Leaks w i l l be evident b y the presence of
gear o i l a r o u n d the leak point. I f leakage i s not evi-
dent, the condition is probably t h e result o f a n u n -
derfill condition.
I f air powered l u b r i c a t i o n equipment is used t o fill
a transmission, be sure t h e e q u i p m e n t is properly
calibrated. E q u i p m e n t out of c a l i b r a t i o n can lead to
an u n d e r f i l l condition.
CLUTCH
PROBLEMS
W o r n , damaged, or misaligned c l u t c h components
can cause h a r d shifting, gear clash a n d noise.
A w o r n p i l o t bushing w i l l cause noise a n d i n p u t
shaft misalignment. The result i s h a r d s h i f t i n g and
noise.
A w o r n or damaged clutch disc, pressure plate, or
release b e a r i n g can cause h a r d s h i f t i n g a n d gear
clash.
Damaged or w o r n clutch h y d r a u l i c components, or
leaks i n t h e f l u i d lines or cylinders w i l l cause h a r d
shifting a n d gear clash. A major f a i l u r e of one o f the
clutch
h y d r a u l i c
cylinders
w i l l
cause
incomplete
clutch release or engagement.
Be sure t h a t the clutch components are a l l i n good
condition before removing t h e transmission for re-
pair.
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