Chevrolet 1977 light duty truck, Руководство по обслуживанию

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b. 2-3 sh ift valve tra in stuck closed (in
downshifted position).
• Direct Clutch:
a. P um p hub - direct clutch oil seal rings -
broken or missing.
b. Clutch piston seals - missing, im properly
assembled or cut.
c. Clutch plates b u r n e d (see B U R N E D
C L U T C H PLATES below).
No First Speed - Starts in Second Speed
(Locks up in LI Range)
Interm ediate Clutch:
1. Too m an y plates in interm ediate clutch pack.
2. Incorrect in term ed iate clutch piston.
Drive in N eutral
• M an u al Linkage - misadjusted, (correct align­
m ent in m an u al lever shift q u a d r a n t is essential).
• Internal Linkage - m a n u a l valve disconnected or
end broken.
• Oil P u m p - line pressure leaking into forward
clutch apply passage.
• F orw ard Clutch - incorrect clutch plate usage or
b urned clutches (see B U R N E D C L U T C H PLATES
below).
No M o tio n in Reverse or Slips in Reverse
(Install pressure gauge)
• Low Oil Level - add oil.
• M an u al Linkage - misadjusted (correct align­
m ent in m a n u a l lever shift q u a d r a n t is essential).
• Low Oil Pressure - refer to LO W LINE
P R E S S U R E above.
• Control Valve Assembly:
a. Valve body gaskets - leaking, da m a g e d or
incorrectly installed.
b. 2-3 shift valve train stuck open (in upshifted
position).
• Interm ediate Servo - piston or pin stuck so
interm ediate overrun band is applied.
• Low and Reverse Clutch - piston outer seal
d a m a g e d or missing.
• Direct Clutch:
a. O uter seal d a m a g e d or missing.
b. Clutch plates b u r n e d (see B U R N E D
C L U T C H PLATES below).
• F orw ard Clutch - clutch does not release (will
cause DRIVE in N E U T R A L ).
Slips in All Ranges or Slips on S tart
(Install pressure gauge)
• Low Oil Level - add oil.
• Low Oil Pressure - refer to LO W LINE
P R E S S U R E above.
• Fo rw ard clutch:
a. C lutch plates b u r n e d (see B U R N E D
C L U T C H PLATES below).
b. P u m p cover oil seal rings broken or worn.
• Case - cross leaks or porosity.
Slipping 1-2 Shift
(Install pressure gauge)
• Low Oil Level - add oil.
• Low Oil Pressure - refer to LOW LINE
PR ESSU R E above.
• 2-3 A ccum ulator - oil ring dam ag ed or missing.
•
1-2 Accumulator - oil ring d am aged, missing or
case bore dam aged.
• P um p-to-C ase G a s k e t - m ispositioned or
dam aged.
• Interm ediate Clutch:
a. Piston seals dam ag ed or missing.
b. Clutch plates b u rn e d (See B U R N E D
C L U T C H PLATES below).
• Case - porosity between channels.
Slipping 2-3 Shift
(Install pressure gauge)
• Low Oil Level - add oil.
• Low Oil Pressure - refer to LOW LINE
PR ESSU RE above.
• Direct Clutch:
a. Piston seals leaks, d a m a g e d or missing.
b. Clutch plates b u rn e d (see B U R N E D
C L U T C H PLATES below).
c. Inspect for p roper n u m b e r and type o f clutch
plates.
• Case - refer to case porosity repair.
Rough 1-2 Shift
(Install pressure gauge)
• High Oil Pressure - refer to HIG H LINE
PR ESSU R E above.
• 1-2 Accumulator:
a. Oil rings dam aged.
b. Piston stuck.
c. Broken or missing spring.
d. Bore dam aged.
• Interm ediate Clutch - check for b urned and
n u m b e r (type) o f plates.
• Case:
a. Check for correct n u m b e r and location of
check balls.
b. Porosity between channels.
Rough 2-3 Shift
(Install pressure gauge)
• High Oil Pressure - refer to H IG H LINE
PR E SSU R E above.
• 2-3 Accumulator:
a. Oil ring dam aged.
b. Piston stuck.
c. Broken or missing spring.
d. Piston bore dam aged.
No Engine Braking in L2