K 1500 Truck 4WD V8-393 6.5L DSL VIN P (1995)
Timing Chain: Testing and Inspection
Fig. 28 Valve timing marks
When the timing chain, gears, front cover, CKP sensor, engine or other components affecting timing are to be replaced, it will be necessary to
reprogram the TDC Offset into the PCM.
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 inspect timing chain deflection, remove front cover then mount a dial indicator on left front of block such that the plunger contacts the timing chain at
the midpoint between the two timing gears. Press the chain outward (parallel to front face engine block) as far as possible by hand, then zero indicator.
Press chain inward as far as possible, then read deflection from dial indicator. Deflection should not exceed 0.80 inch for used chain or 0.50 inch for
new chain. If deflection is excessive, replace chain and/or timing gears.
