V 3500 P/U 4WD V8-379 6.2L DSL (1988)
Camshaft Gear/Sprocket: Service and Repair
Inspection
The timing chain on these engines has an allowable deflection of up to 0.80 inch. However, if timing chain deflection exceeds 0.80 inch, due to
component wear or chain stretch, the engine may experience rough idle, low power, poor fuel economy and/or excessive emission of white smoke. It is
recommended that timing chain deflection be measured whenever the front cover is removed, and any time the above symptoms cannot be traced to a
fuel system malfunction. To check timing chain deflection, proceed as follows:
1.
Remove front cover as outlined.
2.
Mount suitable dial indicator on left front of block positioning indicator so that plunger contacts timing chain at the mid-point between the two
timing gears.
3.
Press timing chain outward (parallel to engine block) as far as possible by hand, then zero indicator.
4.
Press chain inward as far as possible, then read deflection from dial indicator.
5.
Deflection should not exceed 0.80 inch for used chain or 0.50 inch for new chain.
6.
If deflection is excessive, replace chain and/or timing gears as needed.
