Dakota 4WD V6-239 3.9L (1990)
Timing Chain: Service and Repair
Measuring Timing Chain Stretch
Engine Timing Verification
1.
Turn crankshaft until No. 6 exhaust valve is closing and No. 6 intake valve is opening.
2.
Insert a 1/4 inch spacer between rocker arm pad and stem tip of No. 1 intake valve. Allow spring load to bleed valve tappet down, giving in effect
a solid tappet.
3.
Install a suitable dial indicator so plunger contacts valve spring retainer as nearly perpendicular as possible. Zero dial indicator.
4.
Rotate crankshaft clockwise until the valve has lifted .010 inch as indicated by the dial indicator. Do not turn crankshaft any further clockwise as
valve spring might bottom and result in serious damage.
5.
The timing of the crankshaft pulley should now read from 10 degrees before top dead center to 2 degrees after top dead center. Remove spacer.
6.
If reading is not as specified, check sprocket index marks, timing chain for wear and accuracy of DC mark on timing indicator.
