1998 DODGE RAM 1500 Y case

IDENTIFICATION
The transmission has two identification tags
attached to the driver side upper clutch housing (Fig.
2). One tag provides the transmission part number.
The second tag provides sequencing and build date
information. The information on the tags are essen-
tial to correct parts ordering.
OPERATION
The driver selects a particular gear by moving the
shift lever to the desired gear position. As the shift
lever moves the selected shift rail, the shift fork
attached to that rail begins to move. The fork is posi-
tioned in a groove in the outer circumference of the
synchronizer sleeve. As the shift fork moves the syn-
chronizer sleeve, the synchronizer begins to speed-up
or slow down the selected gear (depending on
whether we are up-shifting or down-shifting). The
synchronizer does this by having the synchronizer
hub splined to the mainshaft or the countershaft in
some cases, and moving the blocker ring into contact
with the gear's friction cone. As the blocker ring and
friction cone come together, the gear speed is brought
up or down to the speed of the synchronizer. As the
two speeds match, the splines on the inside of the
synchronizer sleeve become aligned with the teeth on
the blocker ring and friction cone and eventually will
slide over the teeth, locking the gear to the main-
shaft or countershaft through the synchronizer.
DIAGNOSIS AND TESTING
LOW LUBRICANT LEVEL
A low transmission lubricant level is generally the
result of a leak, inadequate lubricant fill or an incor-
rect lubricant level check. A correct lubricant level
check can only be made when the vehicle is level.
Also allow the lubricant to settle for a minute or sobefore checking. These recommendations will ensure
an accurate check and avoid an underfill or overfill
condition. Always check the lubricant level after any
addition of fluid to avoid an incorrect lubricant level
condition.
Leaks can occur at the mating surfaces of the gear
case, adaptor or extension housing, or from the front/
rear seals. A suspected leak could also be the result
of an overfill condition. Leaks at the rear of the
extension or adapter housing will be from the hous-
ing oil seals. Leaks at component mating surfaces
will probably be the result of inadequate sealer, gaps
in the sealer, incorrect bolt tightening or use of a
non-recommended sealer. A leak at the front of the
transmission will be from either the front bearing
retainer or retainer seal. Lubricant may be seen drip-
ping from the clutch housing after extended opera-
tion. If the leak is severe, it may also contaminate
the clutch disc causing the disc to slip, grab and or
chatter.
HARD SHIFTING
Hard shifting is usually caused by a low lubricant
level, improper or contaminated lubricants. The con-
sequence of using non-recommended lubricants is
noise, excessive wear, internal bind and hard shift-
ing. Substantial lubricant leaks can result in gear,
shift rail, synchro, and bearing damage. If a leak
goes undetected for an extended period, the first indi-
cations of component damage are usually hard shift-
ing and noise.
Component damage, incorrect clutch adjustment or
damaged clutch pressure plate or disc are additional
probable causes of increased shift effort. Incorrect
adjustment or a worn/damaged pressure plate or disc
can cause incorrect release. If clutch problem is
advanced, gear clash during shifts can result. Worn
or damaged synchro rings can cause gear clash when
shifting into any forward gear. In some new or
rebuilt transmissions, new synchro rings may tend to
stick slightly causing hard or noisy shifts. In most
cases this condition will decline as the rings wear-in.
TRANSMISSION NOISE
Most manual transmissions make some noise dur-
ing normal operation. Rotating gears generate a mild
whine that is audible, but generally only at extreme
speeds. Severe highly audible transmission noise is
generally the initial indicator of a lubricant problem.
Insufficient, improper or contaminated lubricant
will promote rapid wear of gears, synchros, shift
rails, forks and bearings. The overheating caused by
a lubricant problem, can also lead to gear breakage.
REMOVAL
(1) Shift transmission into Neutral.
Fig. 2 IDENTIFICATION TAG LOCATION
1 - IDENTIFICATION TAGS
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(2) Remove screws attaching shift boot to floorpan.
Then slide boot upward on the shift lever.
(3) Remove the bolts holding the shift tower to the
isolator plate and transmission gear case.
(4) Remove the shift tower and isolator plate from
the transmission gear case.
(5) Raise and support vehicle.
(6) Remove skid plate, if equipped.
(7) Mark propeller shaft/shafts and axle yokes for
installation reference.
(8) Remove propeller shaft.
(9) Disconnect and remove exhaust system as nec-
essary.
(10) Disconnect wires at backup light switch.
(11) Support engine with adjustable safety stand
and wood block.
(12) If transmission is to be disassembled for
repair, remove drain bolt at bottom of PTO cover and
drain lubricant from transmission (Fig. 3).
(13) Remove clutch slave cylinder splash shield, if
equipped.
(14) Remove clutch slave cylinder bolts and move
cylinder aside for clearance.
(15)
Remove wire harness from clips on transmission.
TWO WHEEL DRIVE
(1) Remove bolts/nuts mounting transmission to
the rear mount.
(2) Support and secure transmission with safety
chains to a transmission jack.
(3) Remove rear crossmember bolts and pry out
crossmember.
(4) Remove transmission clutch housing bolts at
the engine block.
(5) Slide transmission and jack rearward until
input shaft clears clutch disc and pressure plate.
(6) Lower transmission jack and remove transmis-
sion from under vehicle.
FOUR WHEEL DRIVE
(1) Disconnect transfer case shift linkage at trans-
fer case range lever.
(2) Support and secure transfer case with safety
chains to a transmission jack.
(3) Remove transfer case mounting nuts.
(4) Move transfer case rearward until input gear
clears transmission mainshaft.
(5) Lower transfer case assembly and move it from
under vehicle.
(6) Support and secure transmission with safety
chains to a transmission jack.
(7) Remove bolts/nuts attaching transmission
mount to rear crossmember.
(8) Remove rear crossmember bolts and pry out
crossmember.
(9) Remove transmission clutch housing bolts at
the engine block.
(10) Move transmission rearward until input shaft
clears clutch disc.
(11) Lower transmission and remove it from under
vehicle.
DISASSEMBLY
NOTE: Use Fixture 8241 for moving and handling
the transmission. The fixture supports the transmis-
sion at the center of gravity in order to ease mount-
ing the transmission into the build fixture.
(1)
Mount the transmission into Fixture 8230 (Fig. 4).
Fig. 3 NV5600 DRAIN BOLT
1 - PTO COVER
2 - DRAIN BOLT
Fig. 4 TRANSMISSION FIXTURE
1 - FIXTURE
2 - TRANSMISSION
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(6) Remove primary shift rail detent plunger (Fig.
9).
(7) Remove clutch housing bolts (10) (Fig. 10) from
inside the housing.(8) Remove shift rail blocker bolt (Fig. 11) from the
side of the transmission gear case.
EXTENSION/ADAPTER HOUSING
(1) Remove bolts holding the extension/adapter
housing onto the transmission gear case.
(2) Remove extension/adapter housing from the
transmission gear case with Puller 8244 (Fig. 12).
NOTE: It may be necessary to straighten the housing
during removal due to the tendency for the reverse
idler shaft to bind into one side of the housing.
Fig. 9 PRIMARY SHIFT RAIL DETENT PLUNGER
1 - DETENT PLUNGER
Fig. 10 CLUTCH HOUSING BOLTS
1 - BOLTS (10)
Fig. 11 SHIFT RAIL BLOCKER BOLT
1 - BLOCKER BOLT
Fig. 12 TRANSMISSION CASE PULLER
1 - PULLER
2 - EXTENSION/ADAPTER HOUSING
DRMANUAL TRANSMISSION - NV5600 21 - 93
MANUAL TRANSMISSION - NV5600 (Continued)

(12) Remove reverse shift fork and synchronizer as
an assembly from the reverse shift rail and the out-
put shaft (Fig. 24).
TRANSMISSION GEAR CASE
(1) Remove remaining bolts holding the transmis-
sion gear case to the clutch housing.
(2) Remove the shift socket roll pin witha6mm
(7/32 in.) punch and hammer.
(3) Turn shift socket so it won't catch the case
when lifting it up.
(4) Install Fixture 8232 to the transmission gear
case.
(5) Attach an engine crane or equivalent to Fixture
8232 and remove the transmission gear case from the
clutch housing (Fig. 25).
(6) Remove rear output shaft and countershaft
bearing races from the transmission gear case with a
brass drift and hammer.
GEARTRAIN
(1) Remove bolts holding the 5-6 crossover bracket
to the clutch housing (Fig. 26).
Fig. 24 REVERSE SHIFT FORK AND SYNCHRO
1 - REVERSE SYNCHRO
2 - REVERSE SHIFT FORK
Fig. 25 TRANSMISSION CASE LIFT FIXTURE
1 - FIXTURE
2 - TRANSMISSION CASE
Fig. 26 5-6 CROSSOVER BRACKET BOLTS
1 - 5-6 CROSSOVER BRACKET
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(5) Remove input shaft oil guide and retainer seal
(Fig. 50).
CLEANING - TRANSMISSION
Clean the gears, bearings shafts, extension/adapter
housing and gear case with solvent. Dry all parts
except the bearings with compressed air. Allow the
bearings to either air dry or wipe them dry with
clean shop towels.
INSPECTION
NOTE: Minor corrosion, nicks, or pitting can be
smoothed with 400 grit emery and polished out with
crocus cloth.
Inspect the reverse idler gear, bearings, shaft and
thrust washers. Replace the bearings if the rollers
are worn, chipped, cracked, flat-spotted or brinnelled.
Replace the gear if the teeth are chipped, cracked or
worn thin.
Inspect the front bearing retainer and bearing cup.
Replace the bearing cup if scored, cracked, brinnelled
or rough. Check the release bearing slide surface of
the retainer carefully. Replace the retainer if worn or
damaged in any way.
Inspect mainshaft bearing surfaces, splines, snap
ring grooves and threads. Replace the shaft if any
surfaces exhibit considerable wear or damage.
Inspect the countershaft and bearings. Replace the
shaft if any surfaces exhibit considerable wear or
damage.Inspect shift forks for wear and distortion. Check
fit of the sleeve in the fork to be sure the two parts
fit and work smoothly. Replace the fork if the roll pin
holes are worn oversize or damaged. Do not attempt
to salvage a worn fork. Replace shift fork roll pins if
necessary or if doubt exists about their condition.
The all bearings for wear, roughness, flat spots,
pitting or other damage. Replace the bearings if nec-
essary.
Inspect the blocker rings and fiction cones. replace
either part if worn or damaged in any way. Replace if
the friction material is burned, flaking off or worn.
Inspect synchro components wear or damage.
Replace parts if worn, cracked or distorted.
Inspect all of the thrust washers and locating pins.
Replace the pins if bent or worn. Replace the wash-
ers if worn or the locating pin notches are distorted.
Inspect the case and housing/adapter sealing and
mating surfaces are free of burrs and nicks. Inspcet
the alignment dowels in the case top surface and in
the housing/adapter are tight and in good condition.
Replace the gear case or housing/adapter if cracked
or broken.
ASSEMBLY
NOTE: Gaskets are not used in the transmission.
Use Mopar Gasket Maker or equivalent on all gear
case and extension housing sealing surfaces.
OUTPUT SHAFT
(1) Place second gear on bench with the synchro
clutch ring up.
(2) Install second gear synchro inner blocker ring
onto second gear (Fig. 51).
Fig. 50 OIL GUIDE AND SEAL
1 - INPUT SHAFT OIL GUIDE
2 - INPUT SHAFT OIL SEAL
Fig. 51 INNER BLOCKER RING
1 - INNER BLOCKER RING
2 - GEAR
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CAUTION: Do not damage input shaft seal with the
input shaft splines.
(11) With the geartrain approximately 1/4 in. from
the clutch housing, remove Holding Tool 8242 from
the 5-6 synchro (Fig. 81).
(12) Install 5-6 crossover bracket and arm to the
shift rails and the clutch housing.
(13) Lower geartrain the remainder of the way
into the clutch housing.
(14) Install the 5-6 crossover bracket bolts and
tighten to 28 N´m (20 ft. lbs.) (Fig. 82).(15) Remove engine crane and Fixture 8232 from
the output shaft and the countershaft.
TRANSMISSION GEAR CASE
(1) Install rear output shaft bearing race into the
transmission gear case with Installer C-4308 and
Handle C-4171.
(2) Install rear countershaft bearing race into the
transmission gear case with Installer 8153 and Han-
dle C-4171.
(3) Install Fixture 8232 to the transmission gear
case.
NOTE: Shift socket must be loose on the shift shaft
and is rotated a minimum of 90É from its normal
position. This will ensure enough clearance to
install the transmission gear case.
(4) Apply sealant to the clutch housing.
(5) Attach an engine crane or equivalent to Fixture
8232 and install the transmission gear case onto the
clutch housing (Fig. 83).
(6) Install clutch housing bolts and tighten to 48
N´m (35 ft.lbs.).
(7) Install shift socket roll pin with a suitable 6
mm (7/32 in.) punch and hammer.
MAINSHAFT AND COUNTERSHAFT ENDPLAY
(1) With transmission in vertical position, use
Socket 6993 to rotate the shafts and seat the bear-
ings.
Fig. 81 HOLDING TOOL
1 - HOLDING TOOL
2 - 5-6 SYNCHRO
Fig. 82 5-6 CROSSOVER BRACKET BOLTS
1 - 5-6 CROSSOVER BRACKET
Fig. 83 LIFT FIXTURE
1 - FIXTURE
2 - TRANSMISSION CASE
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(2) Measure mainshaft endplay with Dial Indicator
Set C-3339 and Extension Rod 8161 installed onto
the rear of the transmission gear case (Fig. 84).
(3) Measure countershaft end-play with Dial Indi-
cator Set C-3339 and Extension Rod 8161 installed
onto the rear of the transmission gear case (Fig. 85).
(4) Rotate transmission into a horizontal position
and remove the input shaft retainer.
(5) Install shims necessary to achieve an end-play
of 0-0.10 mm (0-0.004 in.) for the mainshaft and
countershaft.
NOTE: Countershaft shims go between the bearing
race and spacer. Mainshaft shims go into the input
shaft retainer.
(6) Install anewinput shaft seal into the input
shaft retainer with Installer C-4965.
(7) Install input shaft oil guide with C-3972-A and
Handle C-4171.
(8) Apply sealer to the input shaft retainer and
install retainer onto the clutch housing. Install bolts
and tighten to 28 N´m (20 ft.lbs.).
REVERSE GEAR
(1) Install reverse shift fork and synchronizer as
an assembly onto the reverse shift rail and output
shaft (Fig. 86).NOTE: Raised square shoulder and snap-ring on
the synchro face the case.
Fig. 84 MEASURE MAINSHAFT ENDPLAY
1 - DIAL INDICATOR
2 - EXTENSION ROD
3 - MAIN SHAFT
Fig. 85 MEASURE COUNTERSHAFT END-PLAY
1 - EXTENSION ROD
2 - DIAL INDICATOR
3 - COUNTERSHAFT
Fig. 86 REVERSE SHIFT FORK AND SYNCHRO
1 - REVERSE SYNCHRO
2 - REVERSE SHIFT FORK
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MANUAL TRANSMISSION - NV5600 (Continued)

(10) Install reverse countershaft rear bearing onto
the countershaft reverse gear assembly with Installer
C-4652 and Handle C-4171.
(11) Install reverse idler gear rear bearing, bearing
spacer, front bearing, and front thrust washer onto
the idler gear shaft.
(12) Install idler and reverse countershaft gears
together (Fig. 90).
(13) Install reverse idler thrust washer from the
reverse idler.
(14) Install crossover cam rollers and pin (Fig. 91).EXTENSION/ADAPTER HOUSING
(1) Install extension housing bushing with
Installer 8156 and Handle C-4171, if necessary. The
oil feed hole must be at the 12 o'clock position when
installed.
(2) On 4X2 vehicles, install extension housing seal
with Installer 8154 and Handle C-4171, with the
weep hole at the bottom.
NOTE: Drain hole located in the dust boot portion
of the seal must face downward ( toward the
ground) when installed.
(3) On 4X4 vehicles, install adapter housing seal
with Installer C-3860-A and Handle C-4171.
(4) Install the crossover cam bushing into the
extension/adapter housing with Installer 8239 and
Handle C-4171.
(5) Clean the rear of the transmission case of all
sealer.
(6) Install reverse countershaft gear bearing race
onto the reverse countershaft gear bearing.
(7) Measure the distance from the back of the
bearing race to Gauge Bar 6311 (Fig. 92).
(8) Measure thickness of the gauge bar and record
the total of the two measurements.
(9) Clean all the sealer from the extension/adapter
housing.
Fig. 90 REVERSE IDLER AND COUNTERSHAFT
GEARS
1 - REVERSE IDLER GEAR
2 - COUNTERSHAFT REVERSE GEAR
Fig. 91 CROSSOVER CAM ROLLERS AND PIN
1 - CROSSOVER CAM PIN
2 - CROSSOVER CAM ROLLERS
Fig. 92 Measure Height of Reverse Countershaft
1 - MEASURE DISTANCE FROM RACE TO GAUGE BAR
21 - 120 MANUAL TRANSMISSION - NV5600DR
MANUAL TRANSMISSION - NV5600 (Continued)