can bus DODGE RAM 1999 Service User Guide

14) Connect test light to ground and probe Orange/Black wire
of door lock actuator connector. If test light illuminates while door
unlock switch is pressed, repair open Orange/Black wire between door
lock actuator and Central Timer Module (CTM). CTM is located behind
right kick panel. If test light does not illuminate while door unlock
switch is pressed, go to next step.
15) Access CTM 18-pin connector C2. Remove connector cover.
Do not disconnect connector. Using an external voltmeter, measure
voltage between ground and CTM 18-pin connector C2 terminal No. 9
(Pink/Black wire). If voltage is more than 9.5 volts while door unlock\
switch is pressed, repair open Pink/Black wire. If voltage is 9.5
volts or less while door unlock switch is pressed, replace CTM.
16) Disconnect inoperative lock switch connector. Using an
external voltmeter, measure voltage between ground and Red wire of
door lock switch connector. If voltage is more than 9.5 volts, repair
open Red wire between door lock switch connector and voltage source.
If voltage is 9.5 volts or less, go to next step.
17) Reconnect door lock switch connector. Measure voltage
between ground and backprobe Pink/Violet wire of door lock switch
connector. If voltage is more than 9.5 volts, go to next step. If
voltage is 9.5 volts or less, replace door lock switch.
18) Access CTM 18-pin connector "B". Remove connector cover.
Do not disconnect connector. Using an external voltmeter, measure
voltage between ground and CTM 18-pin connector "B" terminal No. 13
(Pink/Dark Green wire). If voltage is more than 9.5 volts, replace
CTM. If voltage is 9.5 volts or less, repair open Pink/Dark Green wire
between CTM and door lock switch.
REMOTE KEYLESS ENTRY PROBLEM
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting or connecting any module connector.
1) Using scan tool select SYSTEM MONITORS, then CCD BUS TEST.
If scan tool displays BUS OPERATIONAL, go to next step. If scan tool
does not display BUS OPERATIONAL, go to appropriate VEHICLE
COMMUNICATIONS article.
2) Using scan tool select BODY COMPUTER. If scan tool
displays NO RESPONSE, go to appropriate VEHICLE COMMUNICATIONS
article. If scan tool does not display NO RESPONSE, go to next step.
3) Operate door locks with Remote Keyless Entry (RKE)
transmitter. If doors locked when transmitter was actuated, system is
currently functioning properly. If doors do not lock when transmitter
was actuated, go to next step.
4) Ensure transmitter battery voltage is 3.2 volts. Turn
ignition on. Place transmission in park and disarm anti-theft system.
Using scan tool, select MISCELLANEOUS, then PROGRAM RKE. If BCM IS IN
PROGRAMMING MODE does not appear, exit and select PROGRAM RKE again.
Press any transmitter button. A single chime will announce RKE module
accepted transmission. Repeat procedure for all transmitters used with
vehicle. Operate door locks from reprogrammed transmitter. If door
locks operate properly, system has been repaired. If door locks do not
operate properly, go to next step.
5) Using scan tool, reprogram a known good transmitter:
Operate door locks with reprogrammed transmitter. If doors locked
properly, replace transmitter. If doors did not lock properly, replace
CTM.

disarm switch state CLOSED, replace CTM.
23) Turn ignition switch to START position. If horn does not
sound, go to next step. If horn sounds, go to step 24).
24) Locate Central Timer Module (CTM). CTM is located behind\
right kick panel. Disconnect CTM 14-pin connector C1. Using an
external voltmeter, measure voltage between ground and CTM 14-pin
connector C1 terminal No. 8 (Dark Blue/White wire). If voltage is more\
than 10 volts, replace CTM. If voltage is 10 volts or less, repair
open Dark Blue/White wire between CTM and RUN-ACC fuse in junction
block.
WINDSHIELD WIPER SYSTEM
WIPER PARK SWITCH FAILURE
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting or connecting any module connector.
NOTE: It takes 8 seconds for wiper park switch failure DTC to set.
1) Using scan tool, clear DTCs. See appropriate SELF-
DIAGNOSTICS article. Operate wipers in low speed, then intermittent
mode. Reread DTCs. If WIPER PARK SWITCH FAILURE is displayed, go to
next step. If WIPER PARK SWITCH FAILURE is not displayed, system is
currently functioning properly.
2) Gain access to wiper motor connector. Using an external
voltmeter, measure voltage between ground and wiper motor terminal No.
2 (Dark Green wire). If voltage is more than 9 volts, go to next step.\
If voltage is 9 volts or less, replace wiper motor.
3) Locate Central Timer Module (CTM). CTM is located under
left side of instrument panel. Using an external voltmeter, measure
voltage between ground and backprobe of CTM 14-pin Green connector C1
terminal No. 11 (Dark Green wire). If voltage is 9 volts or less,
replace CTM. If voltage is more than 9 volts, repair short to voltage
in Dark Green wire between CTM and wiper relay or wiper motor.
INTERMITTENT WIPERS INOPERATIVE
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting or connecting any module connector.
1) Using scan tool select CENTRAL TIMER MODULE. If scan tool
displays NO RESPONSE, go to appropriate VEHICLE COMMUNICATIONS
article. If scan tool displays any CCD bus failure message, go to
SYMPTOM IDENTIFICATION. If scan tool does not display NO RESPONSE or
any CCD bus failure message, go to next step.
2) If problem is wipers parking in wrong position, go to next
step. If problem is not wipers parking in wrong position, go to step
5).
3) Gain access to wiper motor connector. Turn wipers on to
low speed. Using an external voltmeter, measure voltage between ground
and wiper motor switch terminal No. 2 (Dark Green wire). If voltage
does not cycle between zero and 12 volts, replace wiper motor. If
voltage cycles between zero and 12 volts, go to next step.

4) Locate Central Timer Module (CTM). CTM is located under
left side of instrument panel. Using an external voltmeter, measure
voltage between ground and backprobe of CTM 14-pin Green connector C1
terminal No. 11 (Dark Green wire). Wipers should be operating at low
speed. If voltage does not cycle between zero and 12 volts, repair
open Dark Green wire between CTM and wiper relay or wiper motor. If
voltage cycles between zero and 10 volts, replace CTM.
5) Using scan tool, monitor intermittent wiper voltage level.
Rotate wiper switch from low intermittent to high intermittent level.
If voltage changes from approximately 2.5 to 12 volts, replace CTM. If
voltage does not change from approximately 2.5 to 12 volts, go to next
step.
6) Disconnect 24-pin multifunction switch connector. Using an
external ohmmeter, measure resistance of White/Dark Blue wire between
multifunction switch connector terminal No. 1 and CTM 14-pin Green
connector C1 terminal No. 12. if resistance is less than 5 ohms,
replace multifunction switch. If resistance is 5 ohms or more, repair
open White/Dark Blue wire between multifunction switch and CTM.
NO WIPER ACTUATION AFTER WASH BUTTON PUSHED
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting or connecting any module connector.
1) Using scan tool select Central Timer Module (CTM). If sca\
n
tool displays NO RESPONSE, go to appropriate VEHICLE COMMUNICATIONS
article. If scan tool displays any CCD bus failure message, go to
SYMPTOM IDENTIFICATION. If scan tool does not display NO RESPONSE or
any CCD bus failure message, go to next step.
2) Turn ignition on. If washer system works, go to next step.
If washer system does not work, see appropriate WIPER/WASHER SYSTEMS
article.
3) Using scan tool, actuate washer. If washer pump sense
displays ON, replace CTM. If washer pump sense does not display ON,
repair open Brown wire between CTM 14-pin connector C1 terminal No. 10
and multifunction switch.
WIPER SPEED SENSITIVE FEATURE INOPERATIVE
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting or connecting any module connector.
1) Using scan tool select Central timer module (CTM). If sca\
n
tool display is not blank or have a CCD bus failure message, go to
next step. If scan tool display is blank or has a CCD bus failure
message, see appropriate VEHICLE COMMUNICATIONS article.
2) Using scan tool, select Powertrain Control Module (PCM).
If scan tool display is not blank or have a CCD bus failure message,
go to next step. If scan tool display is blank or has a CCD bus
failure message, see appropriate VEHICLE COMMUNICATIONS article.
3) Raise and support vehicle. Turn wipers on to lowest
intermittent position. Time interval between wipes. Spin rear wheels
to more than 15 MPH. If interval between wipes decreased to
approximately 18 seconds, system is currently functioning properly. If
interval between wipes did not decrease to approximately 18 seconds,

Removal (AX15 & NV1500)
1) Shift gear selector into 1st or 3rd gear. Raise and
support vehicle. Disconnect necessary exhaust system components.
Remove "Y" pipe and position remaining pipes for working clearance.
Support transmission adjustable jackstand. Disconnect rear cushion and
mounting bracket from transmission or transfer case.
2) Remove rear crossmember. If transmission will be
disassembled for repair, drain transmission fluid. Disconnect
transmission shift linkage, speedometer cable, transfer case vacuum
lines and clutch hydraulic lines. Lower transmission/transfer case
assembly no more than 3" (76 mm). Reaching around transmission case,
unseat and lift shift lever dust boot. Press shift lever retainer
downward, turn retainer counterclockwise, and lift lever and retainer
out of shift tower.
3) Mark front and rear drive shaft and "U" joint for
reassembly reference. Disconnect and remove both drive shafts. Remove
crankshaft position sensor (AX15). Disconnect transmission/transfer
case assembly vent hoses. Remove slave cylinder from clutch housing.
Remove wire harness from clips on transmission case and transfer case.
4) Support transmission/transfer case assembly with
transmission jack. Secure assembly to jack with safety chains.
Reposition adjustable jackstand under engine. Remove clutch housing
brace rod. Remove clutch housing nuts and bolts. Remove
transmission/transfer case assembly.
Installation
To install, reverse removal procedure. Apply high-temperature
grease to release fork, lever, pivot ball stud and pilot bushing
located in end of crankshaft. Fill transmission with appropriate
fluid, if necessary. Tighten all nuts and bolts to specification. See
TORQUE SPECIFICATIONS table.
Removal (NV 3500)
1) Disconnect negative battery cable. Shift transmission to
Neutral. Open console lid and remove bolts attaching console to floor
pan. Lift cup holder bin and remove bolt attaching console to floor
pan. Lift rear of console and pull console rearward to separate from
shift bezel. Remove console from vehicle. Remove screws attaching
shift boot to floor pan and slide boot upward on lever extension.
2) Remove shift lever extension. Raise and support vehicle.
On 4WD models, remove skid plate, if equipped. Mark drive shaft and
axle yoke for alignment reference. Remove drive shaft. Remove exhaust
"Y" pipe. On 4WD models, disconnect and lower remaining exhaust pipes
for clearance as necessary. Disconnect speed sensor harness connector
and back-up light harness connector.
3) Support engine using adjustable jackstand. If transmission
is to be disassembled for repair, drain lubricant from transmission.
On 4WD models, disconnect transfer case shift linkage at transfer case
range lever and remove shift lever from transmission. Remove
bolts/nuts attaching transmission to rear mount.
4) Support transmission with a transmission jack. Secure
transmission with safety chains. Remove rear crossmember. On 4WD
models, support transfer case with transmission jack and secure
transfer case to jack with safety chains. Remove transfer case
attaching nuts and move transfer case rearward until input gear clears
transmission output shaft.
5) Lower transfer case assembly and remove it from under
vehicle. On 4WD models, remove clutch slave cylinder splash shield, if
equipped. Remove clutch slave cylinder and move aside for working
clearance. Remove starter. Remove transmission splash shield. Remove
transmission harness wires from clips on transmission shift cover.
6) Lower transmission slightly. Remove shift tower and lever
assembly. Remove transmission-to-engine attaching bolts. Slide

transmission and jack rearward until input shaft clears clutch disc.
Lower transmission jack and remove transmission from under vehicle.
Installation
1) To install, reverse removal procedure. Apply high-
temperature grease to pilot bushing located in end of crankshaft. Also
apply grease to release bearing bore, release fork, release fork ball
stud and drive shaft slip yoke. Apply sealer to threads of drain plug
before installing in case.
2) Align reference marks made on drive shaft(s) and "U"
joints during removal. After installing clutch assembly and housing,
tighten housing bolts nearest alignment dowels first. During final
transmission installation, install shims between clutch housing and
transmission at appropriate bolt location. Tighten all nuts and bolts
to specification. See TORQUE SPECIFICATIONS table.
TRANSMISSION (RAM PICKUP)
Removal (NV3500 & NV5600)
1) Disconnect negative battery cable. Shift transmission to
Neutral. Remove shift boot bezel screws and slide boot upward on lever
extension. Remove shift tower and lever assembly. Raise and support
vehicle.
2) On 4WD models, remove skid plate, if equipped. Remove
crankshaft position sensor. Mark drive shaft and axle yoke for
alignment reference. Remove drive shaft. Remove exhaust "Y" pipe. On
4WD models, disconnect and lower remaining exhaust pipes for
clearance, as necessary. Disconnect speed sensor harness connector.
3) Support engine using adjustable jackstand. If transmission
is to be disassembled for repair, drain lubricant from transmission.
On 4WD models, disconnect transfer case shift linkage at transfer case
range lever and remove shift lever from transmission. Remove
bolts/nuts attaching transmission to rear mount.
4) Support transmission with a transmission jack. Secure
transmission with safety chains. Remove rear crossmember. On 4WD
models, support transfer case with transmission jack and secure
transfer case to jack with safety chains. Remove transfer case
attaching nuts and move transfer case rearward until input gear clears
transmission output shaft.
5) Lower transfer case assembly and remove it from under
vehicle. On 4WD models, remove clutch slave cylinder splash shield, if
equipped. Remove clutch slave cylinder and move aside for working
clearance. Remove starter. Remove transmission splash shield. Remove
transmission harness wires from clips on transmission shift cover. On
some models, it may be necessary to remove front axle struts and oil
filter for access and removal clearance.
6) Lower transmission slightly. Remove shift tower and lever
assembly. Remove transmission-to-engine bolts. Slide transmission and
jack rearward until input shaft clears clutch disc. Lower transmission
jack and remove transmission from under vehicle.
Installation
1) To install, reverse removal procedure. Apply high-
temperature grease to pilot bushing located in end of crankshaft. Also
apply grease to release bearing bore, release fork, release fork ball
stud and drive shaft slip yoke.
2) Apply sealer to threads of drain plug before installing in
case. Align reference marks made on drive shaft(s) and axle yoke(s)
during removal. After installing clutch assembly and housing, tighten
housing bolts nearest alignment dowels first. Tighten all nuts and
bolts to specification. See TORQUE SPECIFICATIONS table.
Removal (NV4500 & NV4500HD)

1) Disconnect negative battery cable. Shift transmission to
Neutral. Remove shift boot bezel screws and slide boot upward on lever
extension. Scribe mark position of extension on shank of shift lever.
2) Raise and support vehicle. On 4WD models, remove skid
plate, if equipped. Mark drive shaft and axle yoke for alignment
reference. Remove drive shaft. Remove exhaust "Y" pipe. On 4WD models,
disconnect and lower remaining exhaust pipes for clearance as
necessary. Disconnect speed sensor harness connector and back-up light
harness connector.
3) Support engine using adjustable jackstand. If transmission
is to be disassembled for repair, drain lubricant from transmission.
See Fig. 9 . On 4WD models, disconnect transfer case shift linkage at
transfer case range lever and remove shift lever from transmission.
Remove bolts/nuts attaching transmission to rear mount.
4) Support transmission with a transmission jack. Secure
transmission with safety chains. Remove rear crossmember. On 4WD
models, support transfer case with transmission jack and secure
transfer case to jack with safety chains. Remove transfer case
attaching nuts and move transfer case rearward until input gear clears
transmission output shaft.
5) Lower transfer case assembly and move it from under
vehicle. On 4WD models, remove clutch slave cylinder splash shield, if
equipped. Remove clutch slave cylinder, and move aside. Remove
starter. Remove transmission splash shield. Remove transmission
harness wires from clips on transmission shift cover. On some models,
it may be necessary to remove front axle struts and oil filter for
access and removal clearance.
6) Lower transmission slightly. Remove shift tower and lever
assembly. Remove transmission-to-engine bolts. Slide transmission and
jack rearward until input shaft clears clutch disc. Lower transmission
jack and remove transmission from under vehicle.
Installation
1) To install, reverse removal procedure. Apply high-
temperature grease to pilot bushing located in end of crankshaft. Also
apply grease to release bearing bore, release fork, release fork ball
stud and propeller shift slip yoke.
2) Apply sealer to threads of drain plug before installing in
case. Align reference marks made on drive shaft(s) and axle yoke(s)
during removal. After installing clutch assembly and housing, tighten
housing bolts nearest alignment dowels first.
3) During final transmission installation, install shims
between clutch housing and transmission at appropriate bolt location.
See CLUTCH HOUSING BORE RUNOUT and CLUTCH HOUSING FACE RUNOUT under
CLUTCH HOUSING (RAM PICKUP) under TESTING. Press extension to scribe
mark made during removal. A 0.12-0.20" (3-5 mm) space should exist
between shift lever isolator, top edge of stub shaft and tool lower
jaw. Tighten all nuts and bolts to specification. See TORQUE
SPECIFICATIONS table.
Fig. 9: Identifying Transmission Drain Bolt (NV4500 & NV4500HD)
Courtesy of Chrysler Corp.
CLUTCH ASSEMBLY

CAUTION: Clutch disc may contain asbestos fibers which can cause
serious health risk. DO NOT sand clutch components. DO NOT
clean components using compressed air. To clean components,
use a water-dampened cloth.
Removal
With transmission and clutch housing removed, mark pressure
plate and flywheel for reassembly reference. Install clutch aligner in
clutch disc to prevent disc from falling. Loosen pressure plate bolts
evenly and in rotation to avoid warping pressure plate. Remove
pressure plate and disc from flywheel. See Fig. 10.
Inspection
1) Check for oil leakage through engine rear main bearing oil
seal and transaxle input shaft seal. Check flywheel and pressure plate
for burned areas, discoloration, cracks, grooves or ridges. Replace as
necessary.
2) Use medium sandpaper (80-180 grade) to clean flywheel
surface, then wipe with mineral spirits. DO NOT flat-machine flywheel
surface. Check facing surfaces for grease or oil contamination. Check
clutch disc for wear. Clutch disc face-to-rivet head distance should
be at least .008" (.20 mm). Check splines of disc hub and transaxle
input shaft.
3) Using straightedge, check pressure plate. Friction area
should be flat to slightly concave, with the inner diameter about 0-.
0039" (0-0.1 mm) less than outer diameter. Using surface plate, check
clutch cover for flatness. Sections around bolt holes should contact
surface plate within .015" (.38 mm). Ensure cover-to-flywheel dowel
fit is snug. Replace clutch assembly as necessary.
NOTE: Before installing clutch disc, ensure flywheel mating
surface, pilot bearing/bushing and clutch release bearing are
in satisfactory condition. Repair and/or replace components
as necessary.
Installation
To install, reverse removal procedure using clutch aligner.
Ensure reference marks are aligned. Tighten pressure plate retaining
bolts evenly a few threads at a time to prevent warpage. See TORQUE
SPECIFICATIONS table.
Fig. 10: Exploded View Of Clutch Assembly (Typical)
Courtesy of Chrysler Corp.
PILOT BEARING, CLUTCH RELEASE BEARING & FORK

Attaching hardware
threads damaged ........ A ... Require repair or replacement
of part with damaged threads if
available; otherwise, replace
bushing.
Attaching hardware threads
stripped (threads
missing) ............... A ..... Require replacement of part
with stripped threads if
available; otherwise, replace
bushing.
Binding ................. A .. Require repair or replacement.
Contaminated ............ 1 ............ Suggest replacement.
Deteriorated, affecting
performance ............ A .. Require repair or replacement.
Distorted, affecting
performance ............ A .. Require repair or replacement.
Missing ................. A ............ Require replacement.
Noisy ................... 2 .......... (1) Further inspection
required.
Rubber separating from
internal metal sleeve on
bonded bushing ......... A ............ Require replacement.
Seized .................. A ............ Require replacement.
Shifted (out of
position) .............. B .. Require repair or replacement.
Split ................... A ............ Require replacement.
Surface cracking (weather-
checked) ............... .. ........ No service suggested or
required.
Worn, affecting
performance ............ A .. Require repair or replacement.
Worn close to the end of
its useful life ........ 1 ............ Suggest replacement.
( 1) - If noise isolated to bushing, suggest repair or
replacement.
CAUTION: Use only approved lubricant on rubber bushings.
Petroleum-based lubricants may damage rubber bushings.









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CABLES (SPEEDOMETER)
CABLE (SPEEDOMETER) INSPECTION








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Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Bent .................... A .. Require repair or replacement.
Binding ................. A .. Require repair or replacement.
Bracket bent, affecting
performance ............ A .. Require repair or replacement.
Bracket bent, not
affecting performance .. .. ........ No service suggested or

ROCKER ARMS & ASSEMBLIES
Rocker Studs
Rocker studs are either threaded or pressed in place.
Threaded studs are removed by locking 2 nuts on the stud. Unscrew the
stud by turning the jam nut. Coat the stud threads with Loctite and
install. Tighten to specification.
Pressed in stud can be removed using a stud puller. Ream the
stud bore to proper specification and press in a new oversize stud.
Pressed in studs are often replaced by cutting threads in the stud
bore to accept a threaded stud.
Rocker Arms & Shafts
Mark rocker arms for location. Remove rocker arm retaining
bolts. Remove rocker arms. Inspect rocker arms, shafts, bushings and
pivot balls (if equipped) for excessive wear. Inspect rocker arms
for wear in valve stem contact area. Measure rocker arm bushing I.D.
Replace bushings if excessively worn.
The rocker arm valve stem contact point can be reground,
using special fixture for valve grinding machine. Remove minimum
amount of material as possible. Ensure all oil passages are clear.
Install rocker arms in original locations. Ensure rocker arm is
properly seated in push rod. Tighten bolts to specification. Adjust
valves if required. See VALVE ADJUSTMENT in this article.
Pushrods
Remove rocker arms. Mark push rods for location. Remove push
rods. Push rods can be steel or aluminum, solid or hollow. Hollow
pushrods must be internally cleaned to ensure oil passage to the
rocker arms is cleaned. Check the pushrod for damage, such as loose
ends on steel tipped aluminum types.
Check push rod for straightness. Roll push rod on a flat
surface. Using feeler gauge, check clearance at center. Replace push
rod if bent. The push rod can also be supported at each end and
rotated. A dial indicator is used to detect bends in the push rod.
Lubricate ends of push rod and install push rod in original
location. Ensure push rod is properly seated in lifter. Install rocker
arm. Tighten bolts to specification. Adjust valves if required. See
VALVE ADJUSTMENT in this article.
LIFTERS
Hydraulic Lifters
Before replacing a hydraulic lifter for noisy operation,
ensure noise is not caused by worn rocker arms or valve tips.
Hydraulic lifter assemblies must be installed in original locations.
Remove the rocker arm assembly and push rod. Mark components for
location. Some applications require intake manifold, or lifter cover
removal. Remove lifter retainer plate (if used). To remove lifters,
use a hydraulic lifter remover or magnet. Different type lifters are
used. See Fig. 13.

using ridge reamer. DO NOT remove an excessive amount of material.
Ensure ridge is completely removed.
PISTON & CONNECTING ROD REMOVAL
Note top of piston. Some pistons may contain a notch, arrow
or be marked "FRONT". Piston must be installed in proper direction to
prevent damage with valve operation.
Check that connecting rod and cap are numbered for cylinder
location and which side of cylinder block the number faces. Proper cap
and connecting rod must be installed together. Connecting rod cap must
be installed on connecting rod in proper direction to ensure bearing
lock procedure. Mark connecting rod and cap if necessary. Pistons must
be installed in original location.
Remove cap retaining nuts or bolts. Remove bearing cap.
Install stud protectors on connecting rod bolts. This protects
cylinder walls from scoring during removal. Ensure proper removal of
ridge. Push piston and connecting rod from cylinder. Connecting rod
boss can be tapped with a wooden dowel or hammer handle to aid in
removal.
PISTON & CONNECTING ROD
Disassembly
Using ring expander, remove piston rings. Remove piston pin
retaining rings (if equipped). On pressed type piston pins, special
fixtures and procedures according to manufacturer must be used to
remove piston pins. Follow manufacturer's recommendations to avoid
piston distortion or breakage.
Cleaning
Remove all carbon and varnish from piston. Pistons and
connecting rods may be cleaned in cold type chemical tank. Using ring
groove cleaner, clean all deposits from ring grooves. Ensure all
deposits are cleaned from ring grooves to prevent ring breakage or
sticking. DO NOT attempt to clean pistons using wire brush.
Inspection
Inspect pistons for nicks, scoring, cracks or damage in ring
areas. Connecting rod should be checked for cracks using Magnaflux
procedure. Piston diameter must be measured in manufacturers specified
area.
Using telescopic gauge and micrometer, measure piston pin
bore of piston in 2 areas, 90 degrees apart. This is done to check
diameter and out-of-round.
Install proper bearing cap on connecting rod. Ensure bearing
cap is installed in proper location. Tighten bolts or nuts to
specification. Using inside micrometer, measure inside diameter in 2
areas, 90 degrees apart.
Connecting rod I.D. and out-of-round must be within
specification. Measure piston pin bore I.D. and piston pin O.D. All
components must be within specification. Subtract piston pin diameter
from piston pin bore in piston and connecting rod to determine proper
fit.
Connecting rod length must be measured from center of
crankshaft journal inside diameter to center of piston pin bushing
using proper caliper. Connecting rods must be the same length.
Connecting rods should be checked on an alignment fixture for bent or
twisted condition. Replace all components which are damaged or not
within specification.
PISTON & CYLINDER BORE FIT