Check if the treadwear indicators are showing on the tires. Also check the tires for uneven wear, such as excessive wear on one side of the tread. Check the spare tire condition and pressure if not rotated.

The location of treadwear indicators is shown by a “TWI” or “
” marks,
etc., molded into the sidewall of each tire.
Replace the tires if the treadwear indicators are showing on a tire.
Tires
Tire rotationAir outlet control servo motor (for rear air conditioning system)
ON-VEHICLE INSPECTION
1. INSPECT REAR AIR OUTLET CONTROL SERVO
MOTOR
(a) Inspect servo motor operation.
(1) Connect the positive (+) lead from the battery
to terminal 4 and negative (-) lead to terminal 5,
then check that the arm turns to "FOOT" side
smoothly.
(2) Connect t ...
Removal
HINT:
On the RH side, use the same procedures as on the LH side.
1. REMOVE REAR NO. 1 SEAT ASSEMBLY LH
HINT:
Captain seat type:
Center seat type:
2. REMOVE REAR DOOR WEATHERSTRIP LH
3. REMOVE ROPE HOOK ASSEMBLY
4. REMOVE BACK DOOR SCUFF PLATE
5. REMOVE ROOF HEADLINING GA ...
Inspection
1. INSPECT OIL PUMP RELIEF VALVE
(a) Coat the relief valve with engine oil and check that it
falls smoothly into the valve hole under its own
weight.
If the valve does not fall smoothly, replace the relief
valve. If necessary, replace the oil pump assembly.
2. INSPECT OIL PUMP ROTOR SET
...