Файл: 92FWD_9.pdf

Fig. 2 Mark Pistons

(1)Mark Identify Pistons. The pistons are not interchangeable from bank to bank (Fig. 2).

(2)Mark connecting rod and cap with cylinder number (Fig. 3).

(3)Remove piston rings (Fig. 4).

Fig. 3 Mark Matching Parts

FITTING PISTONS

Measure approximately 2mm (.080 inch) above the bottom of the piston skirt and across the thrust face. (Fig. 6), See Boring Cylinder in Cylinder Block.

FITTING PISTON RINGS

CYLINDER BORE INSPECTION

(1)Measure the cylinder bore at three levels in directions A and B (Fig. 5). Top measurement should be 12mm (.50 inch) down and bottom measurement should be 10mm (.38 inch) up.

(2)Standard bore dimension: 91.1mm (3.587 inch)

(3)Maximum out-of-round or taper: 0.02mm (.0008

inch)

(1)Wipe cylinder bore clean. Insert ring and push down with piston to ensure it is square in bore. The ring gap measurement must be made with the ring positioning at least 16mm (0.63 inch) from bottom of cylinder bore. Check gap with feeler gauge (Fig. 7). Refer to (Fig. 8) for specification.

(2)Check piston ring to groove clearance; Refer to Piston Ring Specification Chart (Fig. 8).

Fig. 4 Removing Piston Rings

Fig. 5 Checking Cylinder Bore Size

Fig. 6 Piston Clearance and Wear

Fig. 7 Check Gap on Piston Rings

Fig. 8 Piston Ring Specification Chart

Fig. 9 Piston Ring Clearance

PISTON RINGSÐINSTALLATION

(1) The No. 1 and No. 2 piston rings have a different cross section. Install rings with manufacturers mark and size mark facing up, to the top of the piston (Fig. 10).

Fig. 10 Piston Ring Installation

CAUTION: Install piston rings in the following order:

(a)Oil ring expander.

(b)Upper oil ring side rail.

(c)Lower oil ring side rail.

(d)No. 2 Intermediate piston ring.

(e)No. 1 Upper piston ring.

Fig. 11 Installing Side Rail

(2)Install the side rail by placing one end between the piston ring groove and the expander. Hold end firmly and press down the portion to be installed until side rail is in position. Do Not use a piston ring expander (Fig. 11).

(3)Install upper side rail first and then the lower side rail.

(4)Install No. 2 piston ring and then No. 1 piston ring (Fig. 12).

(5)Position piston ring end gaps as shown in (Fig.

13).

(6)Position oil ring expander gap at least 45° from the side rail gaps but not on the piston pin center or on the thrust direction.

Fig. 12 Installing Upper and Intermediate Rings

Fig. 13 Piston Ring End Gap Position

(7)Connecting rod front mark 72 must always face forward, toward timing belt end. (Fig. 14)

(8)Install the piston and connecting rod assembly into there respective bore from the cylinder block top.

CAUTION: Piston assemblies are not to be interchanged from bank to bank.

(9) Check alignment marks made during disassembly and that bearing position notches new or used are on the same side as shown in (Fig. 15).

CONNECTING ROD CLEARANCE

(1)Following procedures specified in the Standard Service Procedures Section for Measuring Main Bearing Clearance and Connecting Rod Bearing Clearance. (Fig. 16). Refer to (Fig. 18) for specifications.

(2)Tighten nuts to 52 Nzm (38 ft. lbs.).

Fig. 14 Identify Piston/Rod Assembly for Cylinder Installation

Fig. 15 Connecting Rod and Cap

(3) Remove connecting rod cap and measure Plastigage (Fig. 16).

CAUTION: Do not rotate crankshaft or the Plastigage may be smeared.

CONNECTING ROD SIDE CLEARANCE

Using a feeler gauge, check connecting rod side clearance (Fig. 17). Refer to (Fig. 18) for specification.

Fig. 16 Connecting Rod Checking Bearing

Clearance

Fig. 17 Checking Connecting Rod Side Clearance

Fig. 18 Connecting Rod Clearance Specifications

CRANKSHAFT SERVICE

The crankshaft is supported in four main bearings. All upper bearing shells in the crankcase have oil grooves. All lower bearing shells installed in the monoblock main bearing cap are plain. Crankshaft end play is controlled by thrust washers on the number three main bearing journal.

CRANKSHAFTÐREMOVAL

(1)Remove front mounted oil pump assembly and gasket (Figs. 1 and 2).

(2)Remove rear oil seal retainer and seal as assembly (Fig. 3).

(3)Release monoblock main bearing cap bolts evenly. Remove lower bearing shells and identify for reassembly.

(4)Lift out crankshaft and remove upper thrust washers from each side of number three main bearing in the crankcase (Fig. 1).

INSPECTION

Visually check the main and connecting rod bearing journals for wear, scuffs or scoring and replace if necessary.

Fig. 2 Oil Pump Assembly

CRANKSHAFT OIL CLEARANCE

MECHANICAL MEASUREMENT

Measure the journal outside diameter and the main bearing inside diameter (Figs. 4 and 5). If the clearance exceeds the specifications limit (Fig. 6). Replace the main bearing(s) and if necessary replace the crankshaft.

Fig. 3 Rear Seal Assembly

Fig. 4 Measure Crankshaft Journal O.D.

Fig. 5 Measure Main Bearing I.D.

PLASTIGAGE MEASUREMENT

(1)Remove oil from journal and bearing shell.

(2)Install crankshaft.

(3)Cut plastigage to same length as width of the bearing and place it in parallel with the journal axis. (Fig. 7).

Fig. 6 Crankshaft Clearance Specification

(4) Install the main bearing cap carefully and tighten the bolts to specified torque.

CAUTION: Do not rotate crankshaft or the plastigage will be smeared.

Fig. 7 Measure Oil Clearance with Plastigage

(5) Carefully remove the bearing cap and measure the width of the plastigage at the widest part using the scale on the plastigage package (Fig. 8). Refer to specification (Fig. 6) for proper clearances. Also see Measuring Main and Connecting Rod Bearing Clearance in Standard Service Procedures.

CRANKSHAFT BEARINGS

INSTALLATION

(1) Install upper main bearing shells making certain oil holes are in alignment, and bearing tabs seat in block tabs. All upper bearings have oil grooves. (Fig. 9).

THRUST BEARINGS. Crankshaft thrust bearings (washers) are installed at journal #3 separately from the radial bearings. Thrust bearings shown in

Fig. 8 Measuring Clearance

(Fig. 9) are different, one has end positioning tabs, while the other is plain. One pair of each thrust washers are installed into the block and one pair into the main bearing cap (Fig. 9).

(2)Apply a thin film of grease to plain side of thrust washers and position them on each side of number three main bearing. Grooved surface towards crankshaft.

(3)Oil the bearings and journals and install crank-

shaft.

(4)Install lower main bearing shells without oil grooves in monoblock cap.

(5)Install one pair of thrust washers in cap. Refer to Thrust Bearings (Fig. 9).

(6)Carefully install bearing cap with arrows (Fig.

10)toward timing belt end.

(7)Oil the bearing cap bolt threads, install and tighten bolts progressively in sequence shown in (Fig.

9)to 80 Nzm (60 ft. lbs.) torque.

CHECKING CRANKSHAFT END PLAY

(1)Mount a dial indicator to front of engine, locating probe on nose of crankshaft (Fig. 11).

(2)Move crankshaft all the way to the rear of its travel.

(3)Zero the dial indicator.

(4)Move crankshaft all the way to the front and read the dial indicator. Refer to (Fig. 6) for specification.

CRANKSHAFT OIL SEALS SERVICE

REAR CRANKSHAFT SEAL RETAINER

(1)Install rear crankshaft oil seal in housing with Special Tool MD998718 (Fig. 12).

(2)Apply (Mopar Silcone Rubber Adhesive Sealant or equivalent) to oil seal housing (Fig. 13) per procedure detailed in form-in-place gasket section in Standard Service Procedures.