Jeep Cherokee

 Service Manual

Engine » 4.0L engine » Removal and installation
Camshaft bearings

REMOVAL

The camshaft rotates within four steel-shelled, babbitt- lined bearings that are pressed into the cylinder block and then line reamed. The camshaft bearing bores and bearing diameters are not the same size. They are stepped down in 0.254 mm (0.010 inch) increments from the front bearing (largest) to the rear bearing (smallest).

This permits easier removal and installation of the camshaft.

The camshaft bearings are pressure lubricated.

Camshaft end play is maintained by the thrust plate.

(1) Remove the camshaft. Refer to Camshaft in this section for procedure.

NOTE: It is not advisable to attempt to replace camshaft bearings unless special removal and installation tools are available, such as recommended tool 8544 Camshaft Bushing Remover Installer.

(2) Using Special tool, remove the camshaft bearings

INSTALLATION

(1) Inspect the camshaft bearing journals for uneven wear pattern or finish.

(2) Inspect the camshaft lobes and distributor gear for wear.

(3) Inspect the camshaft thrust plate for wear. If the plate shows excessive wear inspect the camshaft oil pressure relief holes in the rear cam jounral. The relief holes must be clean and free of debris.

CAUTION: Make sure outside diameter of number 1 bearing is clean. Make sure that the bearing is properly installed in the engine block, align the oil hole in the bearing with the oil gallery in the bearing bore. Failure to do so will cause inadequate oil supply for the sprockets and timing chain.

(4) Using special tool, install new camshaft bearings.

(5) Lubricate the camshaft with Mopart engine oil supplement, or equivalent.

(6) Carefully install the camshaft to prevent damage to the camshaft bearings (7) Position the thrust plate and install the two retaining screws. Tighten screws to 24 N·m (18 ft.

lbs.).

(8) Install the camshaft sprocket, crankshaft sprocket and timing chain with the timing marks aligned. Install the sprocket bolt.

(9) Tighten the camshaft sprocket bolt and washer to 68 N·m (50 ft. lbs.).

(10) To verify correct installation of the timing chain, turn the crankshaft two full revolutions then position the camshaft sprocket timing mark as shown in (Fig. 66).

(11) Install the timing chain cover refer to the procedure in this section.

Engine mounts-front

Engine mount-rear

Engine assembly

Intake and exhaust manifold

Exhaust manifold-4.0L engine

Cylinder head cover

Rocker arms and push rods

Valve springs and oil seals

Cylinder head

Valves and valve springs

Hydraulic tappets

Vibration damper

Timing case cover

Timing chain and sprockets

Camshaft

Camshaft bearings

Crankshaft main bearings

Oil pan

Pistons and connecting rods

Crankshaft oil seals-rear

Oil pump

Timing case cover oil seal