AIR B AG R ESTR AIN T S YSTE M
1999 D odge P ic ku p R 1500
1999 AIR BAG RESTRAINT SYSTEMS
DaimlerChrysler Corp.
Dodge: Ram Pickup
DESCRIPTION & OPERATION
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all WARNINGS and SERVICE PRECAUTIONS.
Supplemental Restraint System (SRS) is designed to work in
conjunction with seat belts. SRS helps to reduce the risk or severity
of serious injury during a front-end collision. Driver-side air bag is
stored in a module in steering wheel hub. All models are equipped with
passenger-side air bags. Passenger-side air bag is stored in the
instrument panel, above glove box. All air bags are covered by a pad
bearing the air bag SRS logo.
Air bag(s) inflate and deflate within 1/10th of a second of
impact sensor switches closing. This creates a cushion of air between
driver and steering wheel and passenger and instrument panel.
System consists of an AIR BAG warning light, clockspring,
driver-side and passenger-side air bag modules, Air Bag Control Module
(ACM), one impact sensor (located inside ACM) and an energy reserve
capacitor. The ACM monitors system, stores fault codes (messages) and
provides information to AIR BAG warning light and Data Link Connector
(DLC). When a malfunction occurs, a fault code is stored and AIR BAG
warning light is activated for more than 12 seconds.
When impact sensor registers sufficient deceleration force
during a front-end collision, an electrical charge is sent from ACM to
air bag module inflator via the clockspring. Inflator actuates and
produces nitrogen gas, which inflates air bag(s).
AIR BAG WARNING LIGHT
Whenever ignition switch is in RUN or START position, AIR BAG
warning light on instrument panel will illuminate for 6-8 seconds and
then turn off. This signifies ACM has checked the system and found
that it is functioning properly. If AIR BAG warning light illuminates
for 12 seconds or more, stays on all the time or does not come on, a
system malfunction exists and trouble code will be stored.
IMPACT SENSOR
All models have one impact sensor located inside ACM. Impact
sensor is an accelerometer that measures deceleration. During a front-
end collision, a signal is sent that completes an electrical circuit
to inflators. Inflators actuate and produce nitrogen gas, which
inflates each air bag. Impact sensor is calibrated for a specific
vehicle and react to severity and direction of vehicle impact.
AIR BAG MODULE
WARNING: DO NOT attempt to disassemble air bag modules. Air bag
modules are not serviceable.
Driver-Side
Air bag module is mounted on front face of steering wheel. A
from axle housing clips. Disconnect electrical connector from brake
sensor mounted on top of axle housing (if equipped).
4) Disconnect parking brake cables. Scribe mark on drive
shaft and pinion flange for reassembly reference. Remove bolts and "U"
joint straps at pinion flange. Support drive shaft aside to prevent
damage to rear "U" joint.
5) Remove shock absorber from axle housing. Support axle
housing with floor jack. Remove "U" bolt nuts. Remove "U" bolts and
spring brackets. Lower axle housing from vehicle.
Installation
1) To install, reverse removal procedure. Ensure rear spring
center bolts align with holes in spring pads on axle housing.
2) Ensure reference mark on drive shaft and pinion flange are
aligned. Tighten bolt/nuts to proper specification. See TORQUE
SPECIFICATIONS. Bleed and adjust brakes.
DIFFERENTIAL ASSEMBLY
NOTE: Differential assembly consists of differential carrier and
components mounted in axle housing. For differential assembly
servicing, see DIFFERENTIAL ASSEMBLY under OVERHAUL.
OVERHAUL
DIFFERENTIAL ASSEMBLY
NOTE: Check pinion bearing preload, side play and then ring gear
runout, in this order, before disassembling differential
assembly.
Disassembly
1) Remove axle shafts. See AXLE SHAFT & BEARING under REMOVAL
& INSTALLATION. Using INCH-lb. torque wrench, measure amount of force
required to rotate pinion. This is pinion bearing preload. Record
pinion bearing preload for reassembly reference if front pinion
bearing will be replaced.
2) To check side play, place pry bar between differential
carrier and axle housing. Pry differential carrier to one side and
note if any side play exists. No side play should exist. If side play
exists, remove bolt and adjuster lock. See Fig. 1. Using Adjuster
Rotator (C-4164), tighten adjuster to eliminate side play.
3) To check ring gear runout, install dial indicator on axle
housing at 90 degree angle to ring gear, with stem resting against
flat side of ring gear, opposite gear teeth. Rotate ring gear, and
note ring gear runout.
NOTE: Ring gear must be removed from differential carrier before
checking differential carrier flange runout. Differential
carrier and bearings must be reinstalled in axle housing to
check differential carrier flange runout.
4) Mark ring gear and differential carrier at point of
maximum ring gear runout for reassembly reference. If ring gear runout
does not exceed .005" (.13 mm), differential carrier and ring gear are\
okay. If ring gear runout exceeds .005" (.13 mm), check differential
carrier flange runout once ring gear is removed.
5) Remove brake sensor from top of axle housing (if
equipped). Mark bearing caps and axle housing for reassembly
reference.
CAUTION: Mark all bearing races and adjusters in relation to their
with tip resting on the main bearing journal area. See Fig. 21.
Rotate crankshaft and note reading. Journal runout must not exceed
specification. Repeat procedure on all main bearing journals.
Crankshaft must be replaced if runout exceeds specification.
Fig. 21: Measuring Crankshaft Main Bearing Journal Runout - Typical
This Graphic For General Information Only
INSTALLATION
Install upper main bearing in cylinder block. Ensure lock
tab is properly located in cylinder block. Install bearings in main
bearing caps. Ensure all oil passages are aligned. Install rear seal
(if removed).
Ensure crankshaft journals are clean. Lubricate upper main
bearings with clean engine oil. Carefully install crankshaft. Check
each main bearing clearance using Plastigage method. See
MAIN & CONNECTING ROD BEARING CLEARANCE in this article.
Once clearance is checked, lubricate lower main bearing and
journals. Install main bearing caps in original location. Install rear
seal in rear main bearing cap (if removed). Some rear main bearing
caps require sealant to be applied in corners to prevent oil leakage.
Install and tighten all bolts except thrust bearing cap to
specification. Tighten thrust bearing cap bolts finger tight only.
Thrust bearing must be aligned. On most applications, crankshaft
must be moved rearward then forward. Procedure may vary with
manufacturer. Thrust bearing cap is then tighten to specification.
Ensure crankshaft rotates freely. Crankshaft end play should be
checked. See CRANKSHAFT END PLAY in this article.
CRANKSHAFT END PLAY
Dial Indicator Method
Crankshaft end play can be checked using dial indicator.
Mount dial indicator on rear of cylinder block. Position dial
indicator tip against rear of crankshaft. Ensure tip is resting
against flat surface.
Pry crankshaft rearward. Adjust dial indicator to zero.
(1) - Require replacement of units where dents restrict shock
or strut piston rod movement. If dents don't restrict
movement, no service is suggested or required. Especially
critical on mono-tube shocks.
( 2) - This condition can lead to damage of the piston rod,
which, in turn, causes premature piston rod seal wear.
( 3) - Only required if replacing cartridge.
( 4) - CAUTION: If the strut cartridge has been replaced previously,
the oil on the strut housing may be filler oil. The
technician must identify the source of the oil.
( 5) - If noise is isolated to shock or strut, suggest
replacement.
( 6) - Although shocks or struts may have contributed to tire
cupping, an inspection is needed of the entire suspension
system. If the shock or strut is found to be contributing
to the tire cupping, require replacement.
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SPINDLES
SPINDLE INSPECTION \
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Condition Code Procedure
Attaching hardware
broken ................. A ... Require replacement of broken
part.
Attaching hardware
loose .................. A ... Require repair or replacement
of loose part.
Attaching hardware
missing ................ C .. Require replacement of missing
part.
Attaching hardware
threads damaged ........ A ... Require repair or replacement
of part with damaged threads.
Attaching hardware
threads stripped
(threads missing) ...... A ..... Require replacement of part
with stripped threads.
Bent .................... B ............ Require replacement.
Broken .................. A ............ Require replacement.
Race seat area
undersized ............. B ............ Require replacement.
Scored .................. A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
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SPRINGS - COIL, LEAF AND TORSION BAR
When springs are replaced, it is suggested, but not required,
that both springs on an axle be replaced to maintain equal height from
side to side and to provide a balanced ride and proper handling.
When variable rate springs are installed in place of
conventional coil springs, they must be installed in axle sets to
ensure proper handling, uniform ride, and proper chassis height.
Erroneous height measurements may result from: improper tire
inflation, non-standard tire or wheel size, and heavy load in vehicle
or trunk.
SPRING (COIL, LEAF AND TORSION BAR) INSPECTION
Condition Code Procedure
Air pressure incorrect .. B .................. Require repair
Bead broken ............. A ............ Require replacement.
Bead leaking, caused
by tire ................ A .. Require repair or replacement.
Bead wire/cord exposed .. A ............ Require replacement.
Cord or belt material
exposed ................ A ............ Require replacement.
Cord ply separations .... A ............ Require replacement.
Directional/asymmetrical
tires mounted
incorrectly ............ B ....... Require remounting and/or
repositioning.
Irregular tread wear,
affecting performance .. 2 ........ (1) Suggest replacement.
Load ratings less
than OEM
specifications ......... B ............ Require replacement.
Mixed tread types (all
season, performance, mud
and snow) on same axle . A ............ Require replacement.
Number of punctures
exceeds manufacturer's
limit .................. B ............ Require replacement.
Out of balance .......... B . Require rebalance of tire/wheel
assembly.
Ply separation .......... A ............ Require replacement.
Pull or lead, caused
by tire ................ A .. Require repair or replacement.
Radial and bias or
bias-belted ply tires
on same axle ........... B .. Require repair or replacement.
Radials are on the front
and not on the rear .... B ........... ( 2) Require repair or
replacement.
Run flat damage ......... A ............ Require replacement.
Shoulder cut ............ A ............ Require replacement.
Shoulder puncture ....... A ............ Require replacement.
Shoulder with plug ...... A ............ Require replacement.
Sidewall bulge .......... A ............ Require replacement.
Sidewall cut ............ A ............ Require replacement.
Sidewall indentation .... .. ......... No service required or
suggested.
Sidewall puncture ....... A ............ Require replacement.
Sidewall with plug ...... A ............ Require replacement.
Speed rating
designations
different
on same axle ........... 2 .. Suggest repair or replacement.
Tire and wheel assembly
has excessive run-out .. B ........... ( 3) Require repair or
replacement of appropriate
part.
Tires with more than
1/4" diameter difference
on a four-wheel drive
vehicle ................ B ............ Require replacement.
Tread area puncture larger
in diameter than
manufacturer's
specifications ......... B ............ Require replacement.
Tread missing pieces
(1) - Require replacement of units where dents restrict shock
or strut piston rod movement. If dents don't restrict
movement, no service is suggested or required. Especially
critical on mono-tube shocks.
( 2) - This condition can lead to damage of the piston rod,
which, in turn, causes premature piston rod seal wear.
( 3) - Only required if replacing cartridge.
( 4) - CAUTION: If the strut cartridge has been replaced previously,
the oil on the strut housing may be filler oil. The
technician must identify the source of the oil.
( 5) - If noise is isolated to shock or strut, suggest
replacement.
( 6) - Although shocks or struts may have contributed to tire
cupping, an inspection is needed of the entire suspension
system. If the shock or strut is found to be contributing
to the tire cupping, require replacement.
\
\
\
\
\
\
\
SPINDLES
SPINDLE INSPECTION \
\
\
\
\
\
\
Condition Code Procedure
Attaching hardware
broken ................. A ... Require replacement of broken
part.
Attaching hardware
loose .................. A ... Require repair or replacement
of loose part.
Attaching hardware
missing ................ C .. Require replacement of missing
part.
Attaching hardware
threads damaged ........ A ... Require repair or replacement
of part with damaged threads.
Attaching hardware
threads stripped
(threads missing) ...... A ..... Require replacement of part
with stripped threads.
Bent .................... B ............ Require replacement.
Broken .................. A ............ Require replacement.
Race seat area
undersized ............. B ............ Require replacement.
Scored .................. A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
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\
\
\
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SPRINGS - COIL, LEAF AND TORSION BAR
When springs are replaced, it is suggested, but not required,
that both springs on an axle be replaced to maintain equal height from
side to side and to provide a balanced ride and proper handling.
When variable rate springs are installed in place of
conventional coil springs, they must be installed in axle sets to
ensure proper handling, uniform ride, and proper chassis height.
Erroneous height measurements may result from: improper tire
inflation, non-standard tire or wheel size, and heavy load in vehicle
or trunk.
SPRING (COIL, LEAF AND TORSION BAR) INSPECTION
Condition Code Procedure
Air pressure incorrect .. B .................. Require repair
Bead broken ............. A ............ Require replacement.
Bead leaking, caused
by tire ................ A .. Require repair or replacement.
Bead wire/cord exposed .. A ............ Require replacement.
Cord or belt material
exposed ................ A ............ Require replacement.
Cord ply separations .... A ............ Require replacement.
Directional/asymmetrical
tires mounted
incorrectly ............ B ....... Require remounting and/or
repositioning.
Irregular tread wear,
affecting performance .. 2 ........ (1) Suggest replacement.
Load ratings less
than OEM
specifications ......... B ............ Require replacement.
Mixed tread types (all
season, performance, mud
and snow) on same axle . A ............ Require replacement.
Number of punctures
exceeds manufacturer's
limit .................. B ............ Require replacement.
Out of balance .......... B . Require rebalance of tire/wheel
assembly.
Ply separation .......... A ............ Require replacement.
Pull or lead, caused
by tire ................ A .. Require repair or replacement.
Radial and bias or
bias-belted ply tires
on same axle ........... B .. Require repair or replacement.
Radials are on the front
and not on the rear .... B ........... ( 2) Require repair or
replacement.
Run flat damage ......... A ............ Require replacement.
Shoulder cut ............ A ............ Require replacement.
Shoulder puncture ....... A ............ Require replacement.
Shoulder with plug ...... A ............ Require replacement.
Sidewall bulge .......... A ............ Require replacement.
Sidewall cut ............ A ............ Require replacement.
Sidewall indentation .... .. ......... No service required or
suggested.
Sidewall puncture ....... A ............ Require replacement.
Sidewall with plug ...... A ............ Require replacement.
Speed rating
designations
different
on same axle ........... 2 .. Suggest repair or replacement.
Tire and wheel assembly
has excessive run-out .. B ........... ( 3) Require repair or
replacement of appropriate
part.
Tires with more than
1/4" diameter difference
on a four-wheel drive
vehicle ................ B ............ Require replacement.
Tread area puncture larger
in diameter than
manufacturer's
specifications ......... B ............ Require replacement.
Tread missing pieces
WHEEL A LIG NM EN T T H EO RY/O PER ATIO N
1999 D odge P ic ku p R 1500
GENERAL INFORMATION
Wheel Alignment Theory & Operation
ALL MODELS
* PLEASE READ THIS FIRST *
NOTE: This article is intended for general information purposes
only. This information may not apply to all makes and models.
PRE-ALIGNMENT INSTRUCTIONS
GENERAL ALIGNMENT CHECKS
Before adjusting wheel alignment, check the following:
* Each axle uses tires of same construction and tread style,
equal in tread wear and overall diameter. Verify that radial
and axial runout is not excessive. Inflation should be at
manufacturer's specifications.
* Steering linkage and suspension must not have excessive play.
Check for wear in tie rod ends and ball joints. Springs must
not be sagging. Control arm and strut rod bushings must not
have excessive play. See Fig. 1.
Fig. 1: Checking Steering Linkage
* Vehicle must be on level floor with full fuel tank, no
passenger load, spare tire in place and no load in trunk.
Bounce front and rear end of vehicle several times. Confirm