Description
Lock-up System (cont'd)
TOROUE CONVERTER
In B.rl position, in 3rd and 4th, and lDl_- position in 3rd.pressurized fluid is drajned from the back of the torqueconverter through a fluid passage. causing the lock-uppiston to be held against the torque convener cover. Asthis takes place, the mainshaft rotates at the same speedas the engine crankshaft, Together with the hydrauliccontrol, the PCM optimized the timing of the lock_upsystem. Under certain conditions, the lock_up clutch isapplied during deceleration, in 3rd and 4th gear.
The lock-up system controls the range of lock_up accord_ing to lock-up control solenoid valves A and B. and thelinear solenoid. When lock-up control solenoid valves Aand B activate, modulator pressure changes. Lock_upcontrol solenoid valves A and B and the linear solenoidare mounted on the outside of the torque converterhousing. and are controlled by the pclvl.
Lock-up Conditions/Lock-up Control Solenoid Valves/Linear Solenoid Pressure
MODULATOR PRESSURE
.-- LINEAR SOLENOID PRESSURE
LOCK.UP CONTROL. VALVE
LOCK.UP CONTROLSOLENOID VALVELock-up
Conditions
Lock-up Control
Solenoid ValveLineal
Solenoid
PressureAB
Lock-up OFFOFFOFFHig h
Lock-up. HalfONDuty operation
OFF - ON
Lock-up. FullONONHigh
Lock-up
during
decelerationONDuty operation
OFF * ONLowTOROUE CONVERTERCHECI( VALVE
RELIEF VAI-VE
LOCK.UP TIMINGVALVE
^ r______rr r cooLER RELTEF VALVE
t'-
14-34
ATF PUMP
Symptom-to-Component Chart
Hydraulic System (cont'dl
G.
n,
set idle rpm in gear to specified idle speed. lf still no good, adjust motor mounts as outlined in enginesection of this manual.
lf the clutch pack is seized or is excessively worn. inspect the other clutches for wear, and check the orificecontrol valves, CPC valve and linear solenoid for free movement.
lf the linear solenoid is stuck, inspect the clutches for wear.
lmproper alignment or main valve body and torque converter housing may cause ATF pump seizure. Thesymptoms are mostly an rpm-related ticking noise or a high-pitched squeak.
lf the l st clutch feed pipe guide in the end cover is scored by the mainshaft, inspect the ball bearing forexcessive movement in the transmission housing. lf oK, replace the end cover as it is dented. The o-rinounder the guide is probably worn.
Replace the mainshaft if the bushing for the 4th feed pipe is loose or damaged. lf the 4th feed pipe is danFaged or out of round, replace the right side cover.
Replace the mainshaft if the bushing for the 1st feed pipe is loose or damaged. lf the 1st feed pipe is darn-aged or out of round, replace it.
A worn or damaged sprag clutch is mostly a result of shifting the transmission inthe wheels rotate in reverse, such as rocking the vehicle in snow.
or E position while
Inspect for damage and wear:
1. Reverse selector gear teeth chamfers.
2. Engagement teeth chamfers of countershaft 4th and reverse gear.
3. Shift fork for scuff marks in center.
4. Differential pinion shaft for wear u nder pin ion gears.
5. Bottom of 3rd clutch for swirl marks.
Replace items 1,2,3 and 4 if worn or damaged. lf transmission makes a clicking, grinding orwhirring noise,also replace mainshaft 4th gear, reverse idler gear. and countershaft 4th gear in addition to 1, 2, 3 or 4.lf differential pinion shaft is worn, overhaul differential assembly, and replace ATF strainer, and thoroughlyclean transmission, flush torque converter, cooler and lines.lf bottom of 3rd clutch is swirled and transmission makes gear noise, replace the countershaft and final drivengear.
Be very careful not to damage the torque converter housing when replacing the main ball bearing, you
may also damage the ATF pump when you torque down the main valve body. This will result in ATF pumpseizure if not detected. Use the oroper roors.
Install the main seal flush with the torque converter housing. lf you push it into the torque converterhousing until it bottoms out, it will block the fluid return passage and result in damage.
See flushing procedure, page 14-187 and 188.
lf the large clutch piston O-ring is broken, inspect the piston groove for rough machining.
lf the l-2 shift valve is stuck closed, the transmission will not upshift. lf stuck open, the transmission hasno 1st gear.
lf the znd orifice control valve is stuck. inspect the 2nd and 3rd clutch oacks for wear.
lf the 3-4 orifice control valve is stuck, inspect the 3rd and 4th clutch oacks for wear.
lf the clutch pressure control valve is stuck closed, the transmission will not shift out of 1st gear.
lf the ATF strainer is clogged with particles of steel or aluminum, inspect the ATF pump and differentialpinion shaft. lf both are OK and no cause for the contamination is found, replace the torque converter.
Inspect the frame for collision damage.
14-112
Master Cylinder/Brake Booster
Pushrod Glearance Adjustment
NOTEr
. The master cylinder pushrod-to-piston clearancemust be checked and adjustments made, if neces_sary, before installing the master cylinder.. ABS type is shown, conventional brake type is similar.
1. Set the special tool on the master cylinde. body; push
in the center shaft until the top of it contacts the endofthe secondary piston by turning the adjusting nut.
Without disturbing the center shaft's Dosition, installthe specialtool upside down on the booster.Install the master cylinder nuts, and tighten to thespecified torque.
Connect the booster in-line with a vacuum gauge O _
101 kPa (0 - 760 mmHg, 30 in.Hg) to the booster,sengine vacuum supply, and maintain an enginespeed that will deliver 66 kpa (500 mmHg, 20 in.Hg)vacuum.
With a feeler gauge. measure the clearance Detweenthe gauge body and the adjusting nut as shown.
Clearance: 0 - 0.4 mm {0 - 0.02 in)
VACUUM GAUGE(Comm€rcially availeblel0 - 101 kPa{0 - 760 mm Hg, 30 in.Hg)
AOJUSTING NUT
FEELER GAUGE
19-22
10.
NOTE: lf the clearance between the gauge bodyand adjusting nut is 0.4 mm (0.02 in), the pushrod-to-piston clearance is 0 mm. However, if the clear_ance between the gauge body and adjusting nut is0 mm, the pushrod-to-piston clearance is 0.4 mm(0.02 in) or more. Therefore, it must be adjusted andrechecked.
6. lf clearance is incorrect, loosen the star locknut, andturn the adjuster in or out to adjust.
NOTE;
. Adjust the clearance while the specified vacuumis applied to the booster.. Hold the clevis while adjusting.
Tighten the star locknut securely.
Remove the special tool.
0 - 0.4 mm (0 - 0.02 in)
7.
ADJUSTERPUSHRODADJUSTMENT GAUGE07JAG - SD('1(x)
9. Adjust the pushrod length as shown if the boosterrs removed.
STAR LOCKNUT22 N.m{2.2 kg,f.m, 16lbtft)
11610.5 mm{{.571 0.02 in)
PUSHRODLOCKNUT15 N.m 11.5 kgf.m, 11 tbtftl
Install the master cylinder {see page l9-21).
