Dodge Durango (DN) 1998-2003 Service Manual » Engine » Cleaning and inspection »

Cylinder block

CLEANING

Thoroughly clean the oil pan and engine block gasket surfaces.

Use compressed air to clean out:

The galley at the oil filter adaptor hole.
The front and rear oil galley holes.
The feed holes for the crankshaft main bearings.

Once the block has been completely cleaned, apply Loctite PST pipe sealant with Teflon 592 to the threads of the front and rear oil galley plugs. Tighten the plugs to 34 N*m (25 ft. lbs.) torque.

Fig. 137 Checking Oil Pump Cover Flatness

1 - STRAIGHT EDGE

2 - FEELER GAUGE

3 - OIL PUMP COVER

Fig. 138 Measuring Outer Rotor Thickness

Fig. 139 Measuring Inner Rotor Thickness

Fig. 140 Measuring Outer Rotor Clearance in Housing

1 - FEELER GAUGE

2 - OUTER ROTOR

Fig. 141 Measuring Clearance Between Rotors

1 - OUTER ROTOR

2 - FEELER GAUGE

3 - INNER ROTOR

INSPECTION

(1) It is mandatory to use a dial bore gauge to measure each cylinder bore diameter. To correctly select the proper size piston, a cylinder bore gauge, capable of reading in 0.003 mm (.0001 in.) INCREMENTS is required. If a bore gauge is not available, do not use an inside micrometer (Fig. 143).

Fig. 142 Measuring Clearance Over Rotors

1 - STRAIGHT EDGE

2 - FEELER GAUGE

Fig. 143 Bore Gauge-Typical

1 - FRONT

2 - BORE GAUGE

3 - CYLINDER BORE

4 - 49.5 MM (1-15/16 in)

(2) Measure the inside diameter of the cylinder bore at three levels below top of bore. Start perpendicular (across or at 90 degrees) to the axis of the crankshaft and then take two additional reading.

(3) Measure the cylinder bore diameter crosswise to the cylinder block near the top of the bore. Repeat the measurement near the middle of the bore, then repeat the measurement near the bottom of the bore.

(4) Determine taper by subtracting the smaller diameter from the larger diameter.

(5) Rotate measuring device 90 and repeat steps above.

(6) Determine out-of-roundness by comparing the difference between each measurement.

(7) If cylinder bore taper does not exceed 0.025 mm (0.001 inch) and out-of-roundness does not exceed 0.025 mm (0.001 inch), the cylinder bore can be honed. If the cylinder bore taper or out- of-round condition exceeds these maximum limits, the cylinder block must be replaced. A slight amount of taper always exists in the cylinder bore after the engine has been in use for a period of time.

Specifications 4.7L engine

4.7L ENGINE