Safari Van M V6-262 4.3L VIN W CPI (1992)
1.
Disconnect battery.
2.
Drain coolant.
3.
Remove fan shroud.
4.
Remove accessory drive belt.
5.
Remove fan.
6.
Remove the water pump.
7.
Remove crankshaft pulley and harmonic balancer.
8.
Remove transmission torque converter cover. Let it lie on top of exhaust crossover pipe.
9.
Drop the oil pan by leaving the rear two nuts on the crankshaft seal studs about 1/4 inch from tight. The two studs will stabilize the oil pan
and the oil will not have to be drained.
10.
Remove the front cover.
11.
It is recommended that the engine be turned over by hand so the crankshaft and camshaft sprocket timing marks are dot to dot.
12.
Loosen the small diameter balance shaft gear bolt. This is the driven gear and has a TORX drive bolt.
13.
Remove the camshaft sprocket by taking off the lock nut first, then the two bolts.
14.
Remove the large diameter balance shaft (drive) gear.
15.
Remove the small diameter balance shaft driven gear.
16.
Clean all sealing surfaces, removing all old gasket material.
Installation of new matched set balance shaft gears:
1.
Install driven gear (small diameter gear) and bolt finger tight.
2.
Install and align drive gear dot to dot with timing mark of the driven gear.
3.
Install drive gear stud to 16 Nm (12 lb.ft.) to ensure the shoulder of the stud is below the counter bore in the gear.
4.
Install camshaft sprocket and chain. Ensure their timing is correct. If the camshaft and crankshaft have not been disturbed, the crankshaft
and camshaft sprockets should be dot to dot.
5.
Install the camshaft sprocket nut and bolts. Torque to 28 Nm (21 lb.ft.).
6.
Torque driven balance shaft gear bolt to 20 Nm (15 lb.ft.) plus an additional 35° using a J 3660 degree meter, torque driver.
7.
At this point, the gear change is complete. Follow the removal steps in reverse order to install the remaining components. Consult the
service manual for torque specifications.
CORRECTION
II.
The following steps should be followed to diagnose the detonation type rattle noise which occurs between 2000 - 2500 RPM under load (condition
II):
1.
Ensure the ESC (Electronic Spark Control) system is working properly. Refer to the ELECTRONIC SPARK CONTROL section of the
LIGHT DUTY TRUCK FUEL AND EMISSIONS section of the service manual. This section includes an "ELECTRONIC SPARK
CONTROL SYSTEM CHECK" with a fault tree for the 4.3L CPI engine.
2.
Operate the vehicle with premium fuel. If the noise is eliminated, the noise is not coming from the balance shaft rear needle bearing. Refer to
the DRIVEABILITY SYMPTOMS section of the LIGHT DUTY TRUCK FUEL AND EMISSIONS service manual. BRAVADA ONLY:
Refer to Bravada service manual section 6E.
3.
If the ESC system is functioning properly and the noise is still audible using premium fuel, the source of the noise is most probably the rear
