C 2500 Suburban 2WD V8-6.5L DSL Turbo VIN F (1995)
Timing Chain: Service and Repair
Timing chain alignment 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.
REMOVAL
1. Remove camshaft and injection pump gears (front cover removed). Align timing marks as shown in Fig. 8.
2. Remove camshaft sprocket, chain and crankshaft sprocket.
INSTALLATION
1. Install timing chain, crankshaft and camshaft sprockets as an assembly. Ensure timing marks are aligned as shown in Fig. 8.
2. Install camshaft gear, bolt and washer. Tighten bolt to specifications.
3. Install injection pump gear and bolts. Align timing marks.
4. Tighten bolts to specifications.
5. Install front cover.
6. Adjust injection pump timing if new gears, sprockets or timing chain were installed.
