hydraulic system and reaction unit service
DESCRIPTION
HYDRAULIC SYSTEM and REACTION UNIT SERVICE. Chapter 5 Page 98 Lab manual. DIAGNOSE HYDRAULIC and VACUUM CONTROL SYSTEMS. The best way to identify the exact cause of transmission problems is to use the results of a road test: Logic - PowerPoint PPT PresentationTRANSCRIPT
HYDRAULIC SYSTEM and REACTION UNIT SERVICE
Chapter 5 Page 98
Lab manual
DIAGNOSE HYDRAULIC and VACUUM CONTROL
SYSTEMS The best way to identify the exact
cause of transmission problems is to use the results of a road test:
Logic Oil charts circuit charts for the
transmission being worked on.Page 98
PRESSURE TESTS
If the road test does not find the problem, perform a pressure test.
Check minimum line in all ranges. Check maximum line in all ranges. What does that mean?
Page 99
TEST CHART
Idle 1200 RPM 1200 Max TVP
R
N
D
3
2
1D
VALVE BODY SERVICE
Drain transmission. Remove valve body disassemble
halves check for stuck valves. Do NOT remove valves until you
have found the problem. Use a Polaroid camera for check ball
location.
Page 105
CLEANING AND INSPECTION
Individual VB parts are not sold separately.
Use spray carb cleaner, WEAR EYE PROTECTION.
Place unlubricated valve in its bore, hold vertical it should fall out by its own weight.
Page 107
VALVEBODY REASSEMBLE
Use notes. Photos Manuals Place valve body gaskets over
separator plate, Gasket can NOT cover any holes in plate.
DO NOT OVERTIGHTEN VB BOLTS.Page 110
GOVERNOR SERVICE
If diagnostic road test indicates a governor problem.
Remove, disassemble, clean, and inspect.
Two main types of governor problems,– Late shifts– Not starting in first gear from a stop.
Page 111
DISASSEMBLY
Most governors have a Primary and Secondary valve.
Valves should be free to move from their own weight.
Inspect drive gear, if it has one. Clean thoroughly.
Page 112
REASSEMBLY
Do not mix up primary and secondary weights or springs.
Install valves correctly, see fig. 5-20. If governor pressure gauge reads
less than 2 PSI ValveBody problem. If governor pressure gauge reads
more than 2 PSI Governor problem.
Page 112
OIL PUMP SERVICE
The oil pump should be carefully inspected during overhaul, especially if Trans had low line pressure.
Page 113
DISASSEMBLY
Note position and direction of pump gears before removal.
Look at P5-5, P5-6, and P5-7.
Page 114
INSPECTION Inspect the pump bore for scoring on
both its bottom and sides. A front pump bushing with two much
clearance will allow gears to run off center.
Check stator splines for wear. Check all bushings for wear and size. Check halves for warpage.
Page 116
REASSEMBLY
Pump bushing and seal should be installed with proper driver.
Lube bushing and seal lip. Coat pump gears in Trans fluid
before assembly. Use proper tools to align pump
halves.
Page 118
BAND SERVICE
Single or double wrap designs. Cast iron or flex type. Do not flatten out flex band or lining
may crack.
Page 119
INSPECTION Look for chipping, cracks, burn marks,
glazing, nonuniform wear patterns, and flaking.
The drum surface should be checked for discoloration, scoring, glazing, and distortion.
Cast drums should be sanded with 180-grit sandpaper.
The surface of the drum should be flat, check all stamped drums.
BAND ADJUSTMENT Every band must be adjusted when
installed. Some transmissions do not require
periodic band adjustment. Some use adjusting screws, and
some use selective apply pins. The timing of the band application
has a lot to do with how the shift feels. page 120
page 121
SERVO and ACCUMULATOR
Some servos are serviceable in the car.
Some accumulators are serviceable in the vehicle.
One of the main problems are leaks. Check bores for gouges and scoring.
page 122
ACCUMULATORS Remove accumulator cover snap
ring. Remove cover, piston and spring. Be sure to note order of disassembly. Manuals may have poor pictures. Piston in first or spring in first? Check seals rubber, Teflon, or steel.
page 122
SERVOS A servo is connected to a band. Same checks as for a accumulator.
page 123
SEALS
Most original equipment servo seals are of the Teflon type.
Cast iron hook ring may be supplied as replacements.
Be sure to check ring size in the bore it goes in.
Check that the ring are free in ring groves.
page 124
INSPECTION
Page 124
ASSEMBLY
Page 124
SELECTIVE APPLY PINS
Page 124
CLUTCH PACKS Two types of clutch packs: Rotating drum - Case grounded All clutch plates are held in place with
snap rings, with some selective thickness.
There may be two or more snap rings of the same diameter but different thickness or shape.
page 126
DISASSEMBLY Remove snap ring retaining the
pressure plate. Remove friction and steel plates. Use clutch piston spring compressor
to compress spring and remove snap ring.
Remove retainer, springs, and piston. Note direction of seal installation.
page 127
INSPECTION AND CLEANING Make sure that you keep the parts of
each clutch separate. Clean all parts, and air dry. Check all splines. Check retainers and springs. Check wave plates for scoring, height. Check ring groves, bushings on drums.
page 132
CLUTCH PACK REASSEMBLY Install new seals and lube before
installation. Soak frictions in ATF prior to
installation. If clutch has a belleville spring the lower
pressure plate must be rounded on the bottom side.
page 135
CLEARANCE CHECKS Adjust clearance by:
– Selective snap rings – Selective pressure plates– Selective apply rings– Oversize steel plates
Non shifting clutch packs have less clearance than shifting clutch packs.
Clutches with Belleville spring .025” max.page 139
AIR TESTING Check with drums on pump and, Check before valve body is installed.
page 140
ONE-WAY CLUTCHES The durability of these clutches
relies on constant fluid flow during operation.
If failure has occurred trace lube circuit and verify volume and pressure.
page 141
ROLLER CLUTCHES
page 142
Check rollers for roundness. Check springs for distortion. Check races for any irregularities. One spring for each roller. Sand races with a crosshatch
pattern. Check for correct direction of
operation.
SPRAG CLUTCHES Sprag element can not be
disassembled. If an element falls out replace the sprag. Check races for any irregularities. Sand races with a crosshatch pattern. Check for correct direction of operation.
page 142
TRANS COOLER SERVICE Flush cooler at time of overhaul. Check lines for leakage. Check for rubbing on pan,
crossmember, etc. If the fluid can not circulate, it can not
cool. Some radiator Trans coolers have
internal filters.page 142
CASE STUDY
Understand basic theories. Listen to everyone. Believe no one.
Prove it to yourself.