TSB 21-10-98 Rev A
5th Gear Repair Procedure
Date: Sep 25, 1998 - Loss of fifth gear
Models: Models: 1994-1999 BR/BE
Note: THIS BULLETIN APPLIES TO VEHICLES WITH A NV4500 MANUAL
TRANSMISSION AND THE 8.0L GAS ENGINE OR THE 5.9L CUMMINS ENGINE.
Policy: Reimbursable within the
provisions of the warranty.
Fifth Gear Nut removal and Installation - 4X2 ..... 2.5 Hrs.
Fifth Gear Nut removal and Installation - 4X4 ..... 3.4 Hrs.
Add 0.2 Hrs for skid plate.
1 05013887AA Nut,
1 Clamp nut assy
1 Spring disc washer
1 Loctite #272
Cleaner, Mopar Brake Parts
Lubricant, Mopar manual transmission (this is Castrol Syntorque)
Adhesive, Mopar lock and seal
Maker, Mopar gasket (Silicone Rubber Gasket material)
NOTE: An improved output shaft, gear, and nut is available from Standard
Transmission. This revised shaft is fully splined to reduce the 5th gear
vibration that pounds the nut loose. All of the special tools are available
from SPX Miller but
if your gear is loose the only one you will probably need is the nut wrench
- special tool 6743. The other tools can be improvised.
This procedure involves installing a new fifth gear, spring disc washer,
and a revise fifth gear clamp nut.
NOTE: Instructions run for 12 pages. I have posted the figures so people can
see the special tools required and the scope of the procedure. Dave
- Shift transmission into neutral.
- Raise vehicle on appropriate hoist.
- Remove skid plate (if equipped)
- Place a drain pan under transmission.
- Remove PTO cover bottom bolt and drain lubricant into a pan (fig 1)
- Using marker, mark a line across the rear axle pinion yoke and the rear
propeller shaft yoke for installation reference
- If equipped with 2 piece prop shaft, mark outline of center bearing on
frame crossmember for installation reference. Then remove bolts that attach
center bearing to support bracket (fig 2).
- Remove the bolts holding U-joint clamp to pinion yoke.
- Slide slip yoke off transmission/transfer case output shaft and remove
rear prop shaft. If vehicle is not a 4X4, jump to step 21.
- Mark line across front prop shaft yoke at transfer case and prop shaft
yoke at rear front prop shaft.
- Mark line across front prop shaft yoke at front of front prop shaft and
front pinion shaft yoke.
- Remove universal strap bolts at front pinion shaft yoke (fig 3).
- Remove bolts holding prop shaft to transfer case yoke flange.
- Remove front prop shaft.
- Disconnect vent hose and vacuum harness at transfer case switch.
- Disconnect transfer case shift linkage at transfer case range lever. Then
remove transfer case shift mechanism from transmission.
- Support transfer case with transmission jack and secure the case to the
jack with safety chains.
- Remove transfer case attaching nuts.
- Move transfer case rearward until T-case input shaft clears transmission
- Lower T-case assembly and move it from underneath the vehicle.
- Support the transmission with a jack.
- Remove bolts attaching transmission mount to rear crossmember.
- Remove bolts attaching exhaust pipe hanger to transmission.
- Remove 8 bolts that attach the extension/adapter housing to the gear case
- Remove extension/adapter housing.
If equipped, remove rubber spline seal from end of mainshaft (fig 5) and
discard. The seal is mainly used to prevent lubricant loss during shipping
and does not need to be replaced.
Install nut wrench special tool 6743 onto 5th gear nut (fig 6). Be sure
wrench is fully engaged in nut slots and is not cocked.
- NOTE: THERE IS ONE ALIGNMENT DOWEL IN THE GEAR CASE AND ONE IN THE
Position the small end of nut wrench at approximately the 10 o'clock position
Install splined socket Special Tool 6993 (4X2) or 6984 (4X4) onto the mainshaft.
Then install a breaker bar onto the splined socket. Wedge the breaker bar
so that the mainshaft cannot turn while loosening the 5th gear nut (fig 7).
Strike the small end of nut wrench with a heavy soft face hammer to break
the nut loose. During assembly, the nut was torqued to 300 ft-lb. In addition,
it is secured by an interference thread plus loctite adhesive and will require
several firm blows to loosen it. Once the nut is loose, it can be removed
by holding the nut wrench with a breaker bar and rotating the output shaft
with the spline socket and the breaker bar (fig 7).
- NOTE: NUT WRENCH WILL ONLY FIT ONE WAY ON THE NUT.
Remove the roll pins that secure the countershaft fifth gear gear fork
to the shift rail with a pin punch (fig 8). Drive the roll pins from the bottom
of the fork and not the top.
- NOTE: THE NUT MAY ALREADY BE LOOSE AND WILL NOT REQUIRE YOU TO STRIKE
THE NUT WRENCH TO LOOSEN THE NUT.
Remove the snap ring that secures the fifth gear clutch hub and gear onto
the countershaft (fig 9).
Remove fifth gear shift fork, gear and hub, and synchronizer components
as an assembly. Remove assembly by tapping shift fork off rail with a plastic
Remove countershaft fifth gear needle bearing assembly and the cone shaped
rear bearing thrust washer from the end of the countershaft. Note the position
of the washer for assembly reference. Also note that the washer bore has a
notch for a retaining pin.
Remove and retain thrust washer locating pin from countershaft.
Remove fifth gear from the mainshaft using puller Special Tool Set 6444
and the following procedures.
Clean the mainshaft threads with a wire brush.
Clean the mating surface of the extension/adapter housing and the gear
case with Mopar Brake Parts Cleaner p/n 04897150AA.
- Position first half of puller jaw Special Tool 6820 onto fifth gear (fig
- Assemble puller flange Special Tool 6444-1 and puller rods Special Tool
6444-3 for 4X2 models or 6444-4 for 4X4 models (fig 11).
- Slide assembled puller flange and rods onto output shaft. Then seat flange
in notch of puller jaw.
- Position second puller jaw Special Tool 6820 onto gear and the notch
on the puller flange.
- Slide retaining collar Special Tools 6444-8 over puller jaws to hold
them in place (fig 12).
- Install puller and bolt (Special Tool 6444) onto puller rods. Then secure
puller to rods with the retaining nuts (fig 13).
- Tighten puller bolt to remove gear from shaft splines.
Install new fifth gear onto the mainshaft. Use installer Special Tool 6446
to seat the gear onto the mainshaft (fig 14). Gear is seated when it contacts
the rear bearing.
- CAUTION: THE REAR SEAL OF THE EXTENSION/ADAPTER HOUSING
MUST BE PROTECTED FROM THE MOPAR BRAKE PARTS CLEANER WHEN CLEANING THE HOUSING'S
Clean the threads of the new fifth gear nut and the mainshaft with Mopar
Brake Parts Cleaner.
Install the new spring disc washer onto the mainshaft. The concave side
of the washer must be positioned toward the fifth gear (fig 15)
Apply Loctite #272 to the threads of the nut.
**Carefully slide the nut over the mainshaft splines up to the threaded
portion of the mainshaft but do not engage the threads at this time.
The flat side of the nut must face towards fifth gear and the concave washer
Tighten the cross bolt until the gap in the fifth gear clamp nut assembly
Back the cross bolt out one full turn.
- NOTE: IF THE NUT DOES NOT SLIDE EASILY OVER THE MAINSHAFT SPLINES,
LOOSEN THE CROSS BOLT IN 1/4 TURN INCREMENTS UNTIL THE NUT SLIDES OVER THE
Install nut wrench Special Tool 6743 onto the fifth gear nut.
Install splined socket Special Tool 6993 (4X2) or 6984 (4X4) onto the output
shaft and attach a breaker bar to the splined socket. While holding the fifth
gear nut with the nut wrench, tighten the fifth gear nut until it bottoms
onto the fifth gear spring disc washer. Then install a high capacity torque
wrench onto the fifth gear nut wrench and torque the nut to 270-280 ft lb
Tighten the cross bolt on the fifth gear nut. Torque bolt to 8-10 ft lb
Install the fifth gear synchronizer thrush washer pin into the countershaft
bore (fig 17).
Install the fifth gear synchronizer thrust washer onto the countershaft.
The flat side of the washer faces the rear of the transmission (fig 17). Turn
the washer until the pin engages into the thrust washer notch.
Lubricate the fifth gear needle bearing with Mopar NV 4500 Transmission
Lubricant p/n 04874459 and install the bearing onto the countershaft.
Install fifth gear shift fork, gear and hub, and synchronizer components
as an assembly onto the countershaft and shift rail.
Install clutch gear snap ring (fig 9).
- CAUTION: THE ABOVE STEPS ARE CRITICAL FOR THE FIFTH GEAR CLAMP
NUT TO FUNCTION PROPERLY.
Align roll pin holes in shift fork with notches in shift lug rail. Then
install roll pins from top side of fork.
Verify that the alignment dowels in gear case and extension/adapter housing
are in their proper position and are fully seated.
Apply Mopar Gasket Maker to the gear case and extension/adapter housing
Align and install the extension/adapter housing onto the gear case.
Apply Mopar Lock N' Seal p/n 04318031 to the threads of the extension/adapter
Install and tighten the housing bolts to 40 ft lb (54 Nm).
Continue reassemble procedures using Steps 1 through 23 in reverse order.
Once the transmission has been fully assembled, fill the transmission with
8 pints of Mopar NV4500 Transmission Lubricant.
- NOTE: ROLL PINS ARE DIRECTIONAL AND WILL ONLY FIT PROPERLY ONE
WAY DUE TO A SMALLER SHOULDER AT ONE END OF THE PIN.
Thanks to Bob Bergevin for providing this TSB information
This page was edited on: May 3, 2004