1998 DODGE RAM 1500 Driver seat

Inspect output shaft bearing retainer, the
U-shaped retainer must be flat and free of distortion.
Replace the retainer if the threads are damaged or if
the retainer is bent or cracked.
COUNTERSHAFT BEARINGS AND RACES
The countershaft bearings and races are machine
lapped during manufacture to form matched sets.
The bearings and races should not be interchanged.
NOTE: The bearing races are a permanent press fit
in the housings and are NOT serviceable. If a bear-
ing race becomes damaged, the front or rear hous-
ing must be replaced. A new countershaft bearing
will be supplied with each new housing for service
use.
REVERSE IDLER COMPONENTS
Inspect the idler gear, bearing, shaft, thrust
washer, wave washer and thrust plate. Replace the
bearing if any of the needle bearing rollers are worn,
chipped, cracked, flat-spotted or brinnelled. Also
replace the bearing if the plastic bearing cage is
damaged or distorted.
Replace thrust washer, wave washer or thrust
plate if cracked, chipped or worn. Replace idler gear
if the teeth are chipped, cracked or worn thin.
Replace shaft if worn, scored or the bolt threads are
damaged beyond repair. Replace support segment if
cracked or chipped and replace the idler attaching
bolts if the threads are damaged.
Shift Socket
Inspect the shift socket for wear or damage.
Replace the socket if the roll pin or shift shaft bores
are damaged. Minor nicks in the shift lever ball seat
in the socket can be smoothed down with 400 grit
emery or wet/dry paper. Replace the socket if the ball
seat is worn or cracked. Do not reuse the original
shift socket roll pin. Install anewpin during assem-
bly. The socket roll pin is approximately 33 mm
(1-1/4 in.) long.
Output Shaft And Geartrain
Inspect all gears for worn, cracked, chipped or bro-
ken teeth. Also check condition of the bearing bore in
each gear. The bores should be smooth and free of
surface damage. Discoloration of the gear bores is a
normal occurrence and is not a reason for replace-
ment. Replace gears only when tooth damage has
occurred or if the bores are brinnelled or severely
scored.
Inspect the shaft splines and bearings surfaces.
Minor nicks on the bearing surfaces can be smoothed
with 320/420 grit emery and final polished with cro-
cus cloth. Replace the shaft if the splines are dam-aged or bearing surfaces are deeply scored, worn or
brinnelled.
ASSEMBLY
NOTE: Sealers are used at all case joints. Use
Mopar Gasket Maker or equivalent for all case joints
and Mopar silicone sealer or equivalent for the
input shaft bearing retainer.
SYNCHRONIZER
(1) Slide sleeve onto the hub, leaving enough room
to install the spring in the hub and strut in the hub
groove.
(2) Install first spring in the hub, then install a
strut over the spring. Verify spring is seated in the
spring bore in the strut.
(3) Slide sleeve onto the hub far enough to hold
the first strut and spring in place.
(4) Place detent ball in the top of the strut, then
press the ball into place with a small screwdriver.
Work the sleeve over the ball to hold it in place.
(5) Repeat procedure for the remaining springs,
struts and balls. Use tape or rubber bands to tempo-
rarily secure each strut and ball as they are
installed.
(6) Verify the synchro three springs, struts and
detent balls are all in place (Fig. 49).
Fig. 49 SYNCHRONIZER COMPONENTS
1 - SLEEVE
2 - HUB SHOULDER
3 - SPRING (3)
4 - STRUT (3)
5 - DETENT BALL (3)
6 - HUB
DRMANUAL TRANSMISSION - NV3500 21 - 17
MANUAL TRANSMISSION - NV3500 (Continued)

(14) Remove wood block from under countershaft
and lower countershaft front bearing into front bear-
ing cup.
(15) Lubricate countershaft rear bearing cup and
cone with petroleum jelly.
(16) Install countershaft rear bearing cup in gear
case and over rear bearing (Fig. 72). Tap cup into
place with plastic mallet if necessary.
(17) Install countershaft rear bearing plate (Fig.
73).
NOTE: Verify plate is seated in notch in reverse
idler shaft before tightening bearing plate bolts.(18) Apply Mopar silicone adhesive/sealer or equiv-
alent to flange and lip of new cap. Installnewfront
bearing cap in gear case (Fig. 74) with Handle
C-4171 and Installer C-3972-A.
COUNTERSHAFT END PLAY
(1) Rotate countershaft 4-5 times to seat bearings.
(2) Mount dial indicator on case. Then position
indicator plunger on end of countershaft and zero
dial indicator (Fig. 75).
(3) Raise countershaft with screwdriver and note
end play reading on dial indicator. End play should
be 0.051 - 0.15 mm (0.002 - 0.006 in.).
Fig. 72 COUNTERSHAFT REAR BEARING CUP
1 - COUNTERSHAFT REAR BEARING CUP
Fig. 73 COUNTERSHAFT REAR BEARING PLATE
1 - COUNTERSHAFT
2 - REAR BEARING PLATE
3 - IDLER SHAFT
Fig. 74 COUNTERSHAFT FRONT BEARING CAP
1 - FRONT BEARING CAP
Fig. 75 MEASURING COUNTERSHAFT END PLAY
1 - DIAL INDICATOR
2 - COUNTER SHAFT
3 - INDICATOR MOUNTING ARM AND BASE
DRMANUAL TRANSMISSION - NV4500 21 - 65
MANUAL TRANSMISSION - NV4500 (Continued)

(10) Install assembled second gear clutch cone and
rings on mainshaft and in 1-2 synchro hub (Fig. 87).
(11) Install snap ring that secures second gear
clutch cone on mainshaft (Fig. 88). Use narrow blade
screwdriver to work snap ring into hub groove as
shown. Verify snap ring is seated in mainshaft
groove.
NOTE: If snap ring will not fit in groove, clutch cone
is slightly misaligned.(12) Install second gear bearing on mainshaft (Fig.
89).
(13) Install second gear on mainshaft and bearing.
Rotate gear until tabs of second gear clutch ring are
seated in tab slots in gear (Fig. 90).
Fig. 87 SECOND GEAR CLUTCH CONE, CLUTCH
RING AND STOP RING
1 - CLUTCH CONE
2 - STOP RING
3 - CLUTCH RING
Fig. 88 SECOND GEAR CLUTCH CONE SNAP RING
1 - SCREWDRIVER
2 - MAINSHAFT HUB
3 - SNAP RING
4 - SECOND GEAR CLUTCH CONE
Fig. 89 SECOND GEAR BEARING
1 - SECOND GEAR BEARING
Fig. 90 SECOND GEAR
1 - SECOND GEAR
2 - CLUTCH RING TABS
3 - TAB SLOTS (IN GEAR)
DRMANUAL TRANSMISSION - NV4500 21 - 69
MANUAL TRANSMISSION - NV4500 (Continued)

(20) Install synchro stop ring on third gear (Fig.
96). Verify stop ring is seated on cone taper.
(21) If 3-4 synchro was disassembled for service,
reassemble synchro components as follows:
(a) Align and install synchro sleeve on hub (Fig.
97).Front side of hub has a narrow groove
machined in it.
(b) Insert all three synchro struts in slots
machined in sleeve and hub (Fig. 97).
(c) Install and seat synchro springs (Fig. 97).
Use screwdriver to compress springs and seat them
in struts and hub as shown.(22) Start 3-4 synchro assembly on mainshaft with
the hub groove and sleeve groove both facing for-
ward. Tap assembly onto shaft splines until hub is
about 3 mm (0.125 in.) away from third gear stop
ring. Then align stop ring with synchro sleeve and
hub and seat synchro assembly with Installer C-4040
(Fig. 98).
(23) Verify 3-4 synchro hub is seated on shaft with
approximately 3 mm (0.125 in.) of shaft spline visi-
ble.
NOTE: If hub is not seated, stop ring lugs are mis-
aligned. Rotate ring until lugs are engaged in 3-4
hub slots.
(24) Verify that second and third gear rotate freely
at this point. If not, determine the cause and correct.
(25) Invert mainshaft in case or bench.
(26) Install first gear bearing on mainshaft.
(27) Install first gear on shaft with clutch hub side
of gear facing the front of shaft (Fig. 99). Verify tabs
on clutch ring are aligned and seated in first gear
hub.
NOTE: 1-2 synchro hub will not seat properly if
clutch ring tabs are misaligned.
Fig. 96 THIRD GEAR STOP RING
1 - SYNCHRO STOP RING
2 - THIRD GEAR
Fig. 97 SYNCHRO ASSEMBLY (3-4)
1 - STRUT (3)
2 - SPRING (3)
3 - 3-4 SLEEVE
4 - 3-4 HUB
Fig. 98 SEATING 3-4 SYNCHRO ASSEMBLY ON
MAINSHAFT
1 - 3-4 SYNCHRO HUB
2 - HUB GROOVE
3 - INSTALLER C-4040
DRMANUAL TRANSMISSION - NV4500 21 - 71
MANUAL TRANSMISSION - NV4500 (Continued)

(d) Compress first spring with flat blade screw-
driver and slide strut into position in hub slot.
Then work spring into seat in strut with small
hooked tool or screwdriver.
(e) Install second and third struts in same man-
ner as described in step (d).
(f) Work sleeve upward on hub until struts are
centered and seated in sleeve. Sleeve should be in
neutral position after seating struts.
(34) Install reverse gear and synchro assembly on
mainshaft (Fig. 103). Rotate assembly until stop ring
lugs engage in hub slots and gear drops into seated
position.
(35) Install reverse gear thrust washer (Fig. 104).
(36) Install rear bearing on mainshaft with
Installer 6446. Seat bearing on output shaft and
against thrust washer (Fig. 105).
(37) Install fourth gear stop ring in 3-4 synchro
sleeve (Fig. 106).
(38) Install fourth gear clutch gear in stop ring
(Fig. 107).
Fig. 103 REVERSE GEAR
1 - REVERSE GEAR AND SYNCHRO ASSEMBLY
Fig. 104 REVERSE GEAR THRUST WASHER
1 - THRUST WASHER
2 - REVERSE GEAR
Fig. 105 MAINSHAFT REAR BEARING
1 - INSTALLER
2 - MAINSHAFT REAR BEARING
Fig. 106 FOURTH GEAR STOP RING
1 - 3-4 SYNCHRO SLEEVE
2 - FOURTH SPEED STOP RING
Fig. 107 FOURTH GEAR CLUTCH GEAR
1 - FOURTH SPEED CLUTCH GEAR
DRMANUAL TRANSMISSION - NV4500 21 - 73
MANUAL TRANSMISSION - NV4500 (Continued)

The rear servo and governor pressure ports are at
the right rear of the transmission case. The overdrive
clutch pressure port is at the left rear of the case.
Test One - Transmission In Manual Low
This test checks pump output, pressure regulation,
and condition of the rear clutch and servo circuit.
Both test gauges are required for this test.
(1) Connect tachometer to engine. Position tachom-
eter so it can be observed from driver seat if helper
will be operating engine. Raise vehicle on hoist that
will allow rear wheels to rotate freely.
(2) Connect 100 psi Gauge C-3292 to accumulator
port. Then connect 300 psi Gauge C-3293-SP to rear
servo port.
(3) Disconnect throttle and gearshift cables from
levers on transmission valve body manual shaft.
(4) Have helper start and run engine at 1000 rpm.
(5) Move transmission shift lever fully forward
into 1 range.
(6) Gradually move transmission throttle lever
from full forward to full rearward position and note
pressures on both gauges:²Line pressure at accumulator port should be
54-60 psi (372-414 kPa) with throttle lever forward
and gradually increase to 90-96 psi (621-662 kPa) as
throttle lever is moved rearward.
²Rear servo pressure should be same as line pres-
sure within 3 psi (20.68 kPa).
Test Two - Transmission In 2 Range
This test checks pump output, line pressure and
pressure regulation. Use 100 psi Test Gauge C-3292
for this test.
(1) Leave vehicle in place on hoist and leave Test
Gauge C-3292 connected to accumulator port.
(2) Have helper start and run engine at 1000 rpm.
(3) Move transmission shift lever one detent rear-
ward from full forward position. This is 2 range.
(4) Move transmission throttle lever from full for-
ward to full rearward position and read pressure on
gauge.
(5) Line pressure should be 54-60 psi (372-414
kPa) with throttle lever forward and gradually
increase to 90-96 psi (621-662 kPa) as lever is moved
rearward.
Test Three - Transmission In D Range Third Gear
This test checks pressure regulation and condition
of the clutch circuits. Both test gauges are required
for this test.
(1) Turn OD switch off.
(2) Leave vehicle on hoist and leave Gauge C-3292
in place at accumulator port.
(3) Move Gauge C-3293-SP over to front servo port
for this test.
(4) Have helper start and run engine at 1600 rpm
for this test.
(5) Move transmission shift lever two detents rear-
ward from full forward position. This is D range.
(6) Read pressures on both gauges as transmission
throttle lever is gradually moved from full forward to
full rearward position:
²Line pressure at accumulator in D range third
gear, should be 54-60 psi (372-414 kPa) with throttle
lever forward and increase as lever is moved rear-
ward.
²Front servo pressure in D range third gear,
should be within 3 psi (21 kPa) of line pressure up to
kickdown point.
Test Four - Transmission In Reverse
This test checks pump output, pressure regulation
and the front clutch and rear servo circuits. Use 300
psi Test Gauge C-3293-SP for this test.
(1) Leave vehicle on hoist and leave gauge C-3292
in place at accumulator port.
(2) Move 300 psi Gauge C-3293-SP back to rear
servo port.
Fig. 9 Pressure Test Port Locations
1 - REAR SERVO TEST PORT
2 - GOVERNOR TEST PORT
3 - ACCUMULATOR TEST PORT
4 - FRONT SERVO TEST PORT
5 - OVERDRIVE CLUTCH TEST PORT
21 - 142 AUTOMATIC TRANSMISSION - 48REDR
AUTOMATIC TRANSMISSION - 48RE (Continued)

(3) Have helper start and run engine at 1600 rpm
for test.
(4)
Move transmission shift lever four detents rear-
ward from full forward position. This is Reverse range.
(5) Move transmission throttle lever fully forward
then fully rearward and note reading at Gauge
C-3293-SP.
(6) Pressure should be 145 - 175 psi (1000-1207
kPa) with throttle lever forward and increase to 230 -
280 psi (1586-1931 kPa) as lever is gradually moved
rearward.
Test Five - Governor Pressure
This test checks governor operation by measuring
governor pressure response to changes in vehicle
speed. It is usually not necessary to check governor
operation unless shift speeds are incorrect or if the
transmission will not downshift. The test should be
performed on the road or on a hoist that will allow
the rear wheels to rotate freely.
(1) Move 100 psi Test Gauge C-3292 to governor
pressure port.
(2) Move transmission shift lever two detents rear-
ward from full forward position. This is D range.
(3) Have helper start and run engine at curb idle
speed. Then firmly apply service brakes so wheels
will not rotate.
(4) Note governor pressure:
²
Governor pressure should be no more than 20.6
kPa (3 psi) at curb idle speed and wheels not rotating.
²If pressure exceeds 20.6 kPa (3 psi), a fault
exists in governor pressure control system.
(5) Release brakes, slowly increase engine speed,
and observe speedometer and pressure test gauge (do
not exceed 30 mph on speedometer). Governor pres-
sure should increase in proportion to vehicle speed.
Or approximately 6.89 kPa (1 psi) for every 1 mph.
(6) Governor pressure rise should be smooth and
drop back to no more than 20.6 kPa (3 psi), after
engine returns to curb idle and brakes are applied to
prevent wheels from rotating.
(7)
Compare results of pressure test with analysis
chart.
Test Six - Transmission In Overdrive Fourth Gear
This test checks line pressure at the overdrive
clutch in fourth gear range. Use 300 psi Test Gauge
C-3293-SP for this test. The test should be performed
on the road or on a chassis dyno.
(1)
Remove tachometer; it is not needed for this test.
(2) Move 300 psi Gauge to overdrive clutch pres-
sure test port. Then remove other gauge and reinstall
test port plug.
(3) Lower vehicle.
(4) Turn OD switch on.(5) Secure test gauge so it can be viewed from
drivers seat.
(6) Start engine and shift into D range.
(7) Increase vehicle speed gradually until 3-4 shift
occurs and note gauge pressure.
(8) Pressure should be 524-565 kPa (76-82 psi)
with closed throttle and increase to 690-896 kPa
(100-130 psi) at 1/2 to 3/4 throttle. Note that pres-
sure can increase to around 965 kPa (140 psi) at full
throttle.
(9) Return to shop or move vehicle off chassis
dyno.
PRESSURE TEST ANALYSIS CHART
TEST CONDITION INDICATION
Line pressure OK during
any one testPump and regulator
valve OK
Line pressure OK in R
but low in D, 2, 1Leakage in rear clutch
area (seal rings, clutch
seals)
Pressure low in D Fourth
Gear RangeOverdrive clutch piston
seal, or check ball
problem
Pressure OK in 1, 2 but
low in D3 and RLeakage in front clutch
area
Pressure OK in 2 but low
in R and 1Leakage in rear servo
Front servo pressure in 2 Leakage in servo; broken
servo ring or cracked
servo piston
Pressure low in all
positionsClogged filter, stuck
regulator valve, worn or
faulty pump, low oil level
Governor pressure too
high at idle speedGovernor pressure
solenoid valve system
fault. Refer to diagnostic
book.
Governor pressure low at
all mph figuresFaulty governor pressure
solenoid, transmission
control module, or
governor pressure
sensor
Lubrication pressure low
at all throttle positionsClogged fluid cooler or
lines, seal rings leaking,
worn pump bushings,
pump, clutch retainer, or
clogged filter.
Line pressure high Output shaft plugged,
sticky regulator valve
Line pressure low Sticky regulator valve,
clogged filter, worn pump
DRAUTOMATIC TRANSMISSION - 48RE 21 - 143
AUTOMATIC TRANSMISSION - 48RE (Continued)

(7) Bottom front servo piston in bore and install
servo spring.
(8) Install front servo piston rod guide as follows:
(a) Place Tool SP-5560 (or similar size tool) on
guide and position C-clamp on tool and case (Fig.
44).
(b) Slowly compress rod guide while simulta-
neously easing seal ring into bore with suitable
tool.
(9) Install rod guide snap-ring (Fig. 44).
OVERRUNNING CLUTCH, REAR BAND, AND
LOW-REVERSE DRUM
(1) Install overrunning clutch components if not
yet installed.
(2) Position rear band reaction pin and band in
case. Be sure that the twin lugs on the band are
seated against the reaction pin.
(3) Install low-reverse drum. Slide drum through
rear band, onto piston retainer hub and into engage-
ment with overrunning clutch and race.
(4) Install thrust washer in low-reverse drum spot-
face (Fig. 45). Use petroleum jelly to hold washer in
place.
(5) Install snap-ring that secures low-reverse drum
to piston retainer hub (Fig. 45).
(6) Insert the rear band pivot pin part way into
the case.(7) Install rear band adjusting lever and pivot pin.
Be sure lever and the single lug on the band are
aligned and engaged before seating band pivot pin in
case.
Fig. 43 Front Servo Piston
1 - USE SUITABLE TOOL TO HELP SEAT PISTON RING
2 - FRONT SERVO PISTON
Fig. 44 Front Servo Rod Guide And Snap Ring
1 - C-CLAMP
2 - ROD GUIDE
3 - SMALL SCREWDRIVER
4 - ROD GUIDE SNAP-RING
5 - TOOL SP-5560
Fig. 45 Low-Reverse Drum Snap Ring
1 - LOW-REVERSE DRUM
2 - TABBED WASHER
3 - SNAP-RING
21 - 168 AUTOMATIC TRANSMISSION - 48REDR
AUTOMATIC TRANSMISSION - 48RE (Continued)