1997 SUBARU LEGACY low oil pressure

Lower level
3.5
(3.7 US qt, 3.1 Imp qt)
G2M0088
3. Oil Pressure Switch
A: REMOVAL
1) Remove alternator from bracket.
(1) Disconnect connector and terminal from generator.
B2M0017
(2) Remove V-belt cover.
(3) Loosen lock bolt and slider bolt, and remove front
side V-belt.
G2M0090
(4) Remove bolts which install generator on bracket.
G2M0091
2) Disconnect terminal from oil pressure switch.
3) Remove oil pressure switch.
15
2-4SERVICE PROCEDURE
2. Oil Pan and Oil Strainer

1. Engine Lubrication System
Before troubleshooting, make sure that the engine oil level
is correct and no oil leakage exists.
Trouble Possible cause Corrective action
1. Warning light remains
on.1) Oil pressure switch
failureCracked diaphragm or oil leakage within switch Replace.
Broken spring or seized contacts Replace.
2) Low oil pressureClogged oil filter Replace.
Malfunction of oil by-pass valve of oil filter Clean or replace.
Malfunction of oil relief valve of oil pump Clean or replace.
Clogged oil passage Clean.
Excessive tip clearance and side clearance of oil
pump rotor and gearReplace.
Clogged oil strainer or broken pipe Clean or replace.
3) No oil pressureInsufficient engine oil Replenish.
Broken pipe of oil strainer Replace.
Stuck oil pump rotor Replace.
2. Warning light does not
go on.1) Burn-out bulb Replace.
2) Poor contact of switch contact points Replace.
3) Disconnection of wiring Repair.
3. Warning light flickers
momentarily.1) Poor contact at terminals Repair.
2) Defective wiring harness Repair.
3) Low oil pressureCheck for the same pos-
sible causes as listed in
1.—2)
17
2-4DIAGNOSTICS
1. Engine Lubrication System

1. Engine Cooling System
Trouble Possible cause Corrective action
Over-heatinga. Insufficient engine coolantReplenish engine coolant, inspect for leakage, and
repair.
b. Loose timing belt Repair or replace timing belt tensioner.
c. Oil on drive belt Replace.
d. Malfunction of thermostat Replace.
e. Malfunction of engine coolant pump Replace.
f. Clogged engine coolant passage Clean.
g. Improper ignition timingInspect and repair ignition control system.

h. Clogged or leaking radiator Clean or repair, or replace.
i. Improper engine oil in engine coolant Replace engine coolant.
j. Air/fuel mixture ratio too leanInspect and repair fuel injection system.

k. Excessive back pressure in exhaust system Clean or replace.
l. Insufficient clearance between piston and cylinder Adjust or replace.
m. Slipping clutch Repair or replace.
n. Dragging brake Adjust.
o. Improper transmission oil Replace.
p. Defective thermostat Replace.
q. Malfunction of electric fanInspect radiator fan relay, engine coolant temperature
sensor or radiator motor and replace there.
Over-coolinga. Atmospheric temperature extremely low Partly cover radiator front area.
b. Defective thermostat Replace.
Engine coolant
leaks.a. Loosened or damaged connecting units on hoses Repair or replace.
b. Leakage from engine coolant pump Replace.
c. Leakage from engine coolant pipe Repair or replace.
d. Leakage around cylinder head gasket Retighten cylinder head bolts or replace gasket.
e. Damaged or cracked cylinder head and crankcase Repair or replace.
f. Damaged or cracked thermostat case Repair or replace.
g. Leakage from radiator Repair or replace.
Noisea. Defective drive belt Replace.
b. Defective radiator fan Replace.
c. Defective engine coolant pump bearing Replace engine coolant pump.
d. Defective engine coolant pump mechanical seal Replace engine coolant pump.
20
2-5DIAGNOSTICS
1. Engine Cooling System

B2M0329A
2) Hardened facing
Correct by using emery paper or replace.
3) Oil soakage on facing
Replace clutch disc and inspect transmission front oil seal,
transmission case mating surface, engine rear oil seal and
other points for oil leakage.
B2M0330A
4) Deflection on facing
If deflection exceeds the specified value at the outer cir-
cumference of facing, repair or replace.
Limit for deflection:
1.0 mm (0.039 in) at R = 107 mm (4.21 in)
B2M0333A
5) Worn spline, loose rivets and torsion spring failure
Replace defective parts.
G2M0248
2. CLUTCH COVER
Visually check for the following items without
disassembling, and replace or repair if defective.
1) Loose thrust rivet.
2) Damaged or worn bearing contact area at center of
diaphragm spring.
G2M0249
3) Damaged or worn disc contact surface of pressure
plate.
4) Loose strap plate setting bolt.
5) Worn diaphragm sliding surface.
13
2-10SERVICE PROCEDURE
4. Clutch Disc and Cover

1. Clutch System
Condition Possible cause and testing Corrective action
1. Clutch slip-
pageIt is hard to perceive clutch slippage in the early stage, but pay attention to the following symptoms.
(a) Engine revs up when shifting.
(b) High speed driving is impossible; especially rapid acceleration impossible and vehicle speed does not increase in
proportion to an increase in engine speed.
(c) Power falls, particularly when ascending a slope, and there is a smell of burning of the clutch facing.
Method of testing: Put the vehicle in stationary condition with parking brake fully applied. Disengage the clutch and
shift the transmission gear into the first. Gradually allow the clutch to engage while gradually increasing the engine
speed. The clutch function is satisfactory if the engine stalls. However, the clutch is slipping if the vehicle does not
start off and the engine does not stall.
(a) No clutch pedal play Readjust.
(b) No release lever end play Readjust.
(c) Clutch facing smeared by oil Replace.
(d) Worn clutch facing Replace.
(e) Deteriorated diaphragm spring Replace.
(f ) Distorted pressure plate or flywheel Correct or replace.
(g) Defective release bearing holder Correct or replace.
(h) Defective pedal and cable system Correct or replace.
2. Clutch
drags.As a symptom of this trouble, a harsh scratching noise develops and control becomes quite difficult when shifting
gears. The symptom becomes more apparent when shifting into the first gear. However, because much trouble of the
this sort is due to defective synchronization mechanism, carry out the test as described after.
Method of testing: Refer to DIAGNOSTIC DIAGRAM on page after.
It may be judged as insufficient disengagement of clutch if any noise occurs during this test.
(a) Excessive clutch pedal play Readjust.
(b) Excessive clutch release lever play Readjust.
(c) Worn or rusty clutch disc hub spline Replace clutch disc.
(d) Excessive deflection of clutch disc facing Correct or replace.
(e) Seized crankshaft pilot needle bearing Replace.
(f ) Malfunction of pedal and cable system Correct or replace.
(g) Cracked clutch disc facing Replace.
(h) Sticked clutch disc (smeared by oil or water) Replace.
3. Clutch chat-
ters.Clutch chattering is an unpleasant vibration to the whole body when the vehicle is just started with clutch partially
engaged.
(a) Improper clutch cable routing Correct.
(b) Adhesion of oil on the facing Replace clutch disc.
(c) Weak or broken torsion spring Replace clutch disc.
(d) Defective facing contact or excessive disc Replace clutch disc defection.
(e) Warped pressure plate or flywheel Correct or replace.
(f ) Loose disc rivets Replace clutch disc.
(g) Loose engine mounting Retighten or replace mounting.
(h) Improper adjustment of pitching stopper Adjustment.
19
2-10DIAGNOSTICS
1. Clutch System

G2M0299
20) Remove bolts which hold upper side of transmission to
engine.
G2M0300
21) Remove engine from vehicle.
(1) Slightly raise engine.
(2) Raise transmission with garage jack.
(3) Move engine horizontally until mainshaft is with-
drawn from clutch cover.
(4) Slowly move engine away from engine compart-
ment.
CAUTION:
Be careful not to damage adjacent parts or body pan-
els with crank pulley, oil pressure gauge, etc.
19
2-11SERVICE PROCEDURE
2. Engine

B: INSTALLATION
1. Install engine to transmission.
2. Tighten bolts which hold upper side of transmission to engine.
3. Remove lifting device and wire rope.
4. Remove garage jack.
5. Install pitching stopper.
AT model
6. Install torque converter onto drive plate.
7. Install canister and bracket.
8. Install power steering pump on bracket.
9. Tighten nuts which hold lower side of transmission to engine.
10. Tighten nuts which install front cushion rubber onto cross-
member.
11. Install front exhaust pipe and center exhaust pipe.
12. Connect hoses, connectors and cables.
13. Install air intake system.
Air intake duct
Air cleaner element and upper cover.
With A/C
14. Install A/C pressure hoses.
15. Install cooling system.
16. Install battery onto the vehicle, and connect cables.
17. Fill coolant.
18. Check ATF level, and connect if necessary. [AT]
19. Correct power steering oil, and bleed air.
20. Remove front hood stay, and close front hood.
21. Take off the vehicle from lift arms.












20
2-11SERVICE PROCEDURE
2. Engine

No. Part Name Part Number Dimension mm (in) Application
1 Control piston2500 cc 31235AA000—030
13.5
0.030
0.037(0.53150.0012
0.0015), 13.50.023
0.030(0.53150.0009
0.0012),
13.50.016
0.023(0.53150.0006
0.0009), 13.50.009
0.016(0.53150.0004
0.0006)Adjusting side clear-
ance of oil pump
2200 cc 31235AA040 — 070
2 Cam ring 31241AA001 — 03117
0.010
0.017(0.66930.0004
0.0007), 170.003
0.010(0.66930.0001
0.0004),
17+0.004
0.003(0.6693+0.0002
0.0001), 17+0.011
+0.004(0.6693+0.0004
+0.0002)Adjusting side clear-
ance of oil pump
3 Vane (Oil pump) 31243AA000 — 03017
0.030
0.037(0.66930.0012
0.0015), 170.023
0.030(0.66930.0009
0.0012),
170.016
0.023(0.66930.0006
0.0009), 17+0.009
+0.016(0.6693+0.0004
+0.0006)Adjusting side clear-
ance of oil pump
4 Rotor (Oil pump) 31240AA000 — 03017
0.030
0.037(0.66930.0012
0.0015), 170.023
0.030(0.66930.0009
0.0012),
170.016
0.023(0.66930.0006
0.0009), 17+0.009
+0.016(0.6693+0.0004
+0.0006)Adjusting side clear-
ance of oil pump
5Thrust washer
(Reverse clutch)31299AA000 — 0600.7, 0.9, 1.1, 1.3, 1.5, 1.7, 1.9
(0.028, 0.035, 0.043, 0.051, 0.059, 0.067, 0.075)Adjusting end play of
reverse clutch drum
6 Bearing race 803031021 — 0270.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0
(0.031, 0.039, 0.047, 0.055, 0.063, 0.071, 0.079)Adjusting total end
play
7 Retaining plate 31567AA350 — 4004.6, 4.8, 5.0, 5.2, 5.4, 5.6 (0.181, 0.189, 0.197, 0.205,
0.213, 0.220)Adjusting clearance
of reverse clutch
8 Retaining plate31567AA340,
31567AA190 — 2603.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0
(0.134, 0.142, 0.150, 0.157, 0.165, 0.173, 0.181, 0.189,
0.197)Adjusting clearance
of high clutch
9 Retaining plate31567AA010,
31567AA060 — 1104.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2
(0.157, 0.165, 0.173, 0.181, 0.189, 0.197, 0.205)Adjusting clearance
of forward clutch
10 Retaining plate 31567AA410 — 4708.0, 8.2, 8.4, 8.6, 8.8, 9.0, 9.2
(0.315, 0.323, 0.331, 0.339, 0.346, 0.354, 0.362)Adjusting clearance
of overrunning clutch
11Retaining plate
No. 231667AA180 — 2506.5, 6.8, 7.1, 7.4, 7.7, 8.0, 8.2, 8.4
(0.256, 0.268, 0.280, 0.291, 0.303, 0.315, 0.323, 0.331)Adjusting clearance
of low and reverse
brake
12Pressure plate
(Front)31593AA151 — 1813.3, 3.7, 4.1, 4.5
(0.130, 0.146, 0.161, 0.177)Adjusting clearance
of transfer clutch
13Thrust bearing
(35x53xT)806536020,
806535030 — 070,
0903.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0
(0.150, 0.157, 0.165, 0.173, 0.181, 0.189, 0.197)Adjusting end play of
transfer clutch
14Washer
(38.1 x 50 x T)803038021 — 0230.95, 1.00, 1.05
(0.0374, 0.0394, 0.0413)Adjusting backlash
of differential bevel
gear
15 Drive pinion shim 31451AA050 — 1000.150, 0.175, 0.200, 0.225, 0.250, 0.275
(0.0059, 0.0069, 0.0079, 0.0089, 0.0098, 0.0108)Adjusting drive pin-
ion height
5
3-2SPECIFICATIONS AND SERVICE DATA
1. Automatic Transmission and Differential