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DIFFERENTIAL
The differential of the
JH3-051 gearbox is the simple type (with two satellites and two planetary
wheels, one of which making a common body with the tulip of the planetary transmission).
This differential is supported in the clutch – differential crankcase by means of two cylindrical
bearings equipped with balls of various sizes.
The two bearings are pressed in the clutch – differential crankcase.
The crown of the main transmission is assembled by hooping, on the differential crankcase.
DIFFERENTIAL DISMOUNTING
This operation is to be performed after separating the crankcases.
The zero ring (1) is removed from the right planetary shaft, then by means of a pins extractor
and a hammer, the sealing gasket (2) is gently hit in order to make it pivoting.
The oil seal ring is carefully pulled along the grooved part of the planetary pinion in order not
to deteriorate t he grooves.
G earbox dismounting
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Gearbox dismounting
MOUNTING OF THE DIFFERENTIAL ASSEMBLY I N THE CLUTCH CRANKCASE
The differential assembly is pressed into the crankcase, then the stopping safety device (3)
is mounted on the planetary shaft by means of the C.V. 946 device.
Rotate the differential assembly and check the speedometer pinion rotation.
Remounting of the ( C) planetary oil seal ring is performed after this has been oiled, by means
of the CV 945 device and the ( A) protector.
Mount the oiled protector ( A), on the planetary pinion and position the oil seal ( C) by means
of the ( B) device.
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CONTROL AXLE DISMOUNTING
This operation is to be performed after crank-
cases separation.
The control axle is provided with a blocking
element “LOCTOU” –(A) attached on the
crankcase. The sealing is ensured by m eans of the tore
gasket (B).
Remove the elastic pin of the selection lever
(C), then dismount the a ttachment screws, and
retrieve the control axle assembly .
In order to replace the bearing bushing of the control axle, the CV 1162 device, or a tube with
the outer diameter 16.5 mm are to be used. Before mounting the bushing shall be oiled.
CONTROL AXLE REMOUNTING
When remounting the control axle, replace the selection finger pin with a new one.
Remounting is done by performing the dismounting operations in the reverse order, after all
parts have been oiled with oil. Tighten all attachment screws of the control axle assembly at the required moment of
2 daNm.
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Mount the elastic pin for reverse driving axle
attachment by means of the C.V. 560 mandrel.
Ensure the correct positioning of the two cen-
tering bushings and of the magnet.
Mount the springs and the locking balls 1-2
and 3-4 in the mechanisms crankcase, then the
false axes A w ith a 13-mm diameter are i ntro-
duced.
Check the positioning of the 5 th gear oiling
collector and of the aerating connection. Additionally, ensure (check) if the aeratin g t ube
is not damaged or clogged. Apply a continuos layer of
LOCTITE
518 on the gasket surface between the clutch
crankcase and the mechanism crankcase.
Engage the 3 -d gear.
M ount the spring and the 5 th gear lock-
ing ball into the crankcase of the mechanism.
Compress the locking ball and mount the
mechanisms crankcase.
Mount the attachmen t screws and tighten
them at the required moment of 2,5 daNm ,
after rotating the primary shaft, i n order t o
ensure o correct bearings setting. Retrieve the false axes.
REMARK :
The tightening at the requi red mo-
ment of al l the screws must be done i n
no mo re tha n 30 mi nutes a fter the
mounting of t he mechanisms crankcase,
b ecause of the polymerization of
LOCTITE 518.
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C.V. 1175
C.V. 31-01
Mount the 5-th gear fix pinion on the sec-
ondary shaft by means of the C.V. 1175 de-
vice. Dismount the C.V. 1175 device and mount
the secondary shaft screw, oiled with 3 drops
of LOCTITE FRENBLOC.
Remount on the primary shaft, observing
the following sequence :
- the support washers (with the larger side
towards the pinion ) - the bushing under the pinion;
- the fre e 5 th pinion equipped with its
synchroni ser ring ;
- the 5-th gear hub equipped with its spring
- the fork together with the 5 th sliding
collar. Engage the 1-st gear with the gear lever and
the 5 th gear by sliding the 5-th gear fork on its
axle. Mount the nut and the screw and tighten them
at the required moment: - primary shaft nut : 19 daNm;
- secondary shaft screw : 7 daNm.
Mount the pin of the 5 th gear fork by means
the CV 31 01 device.
Gearb ox dismounting
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Observe the mounting direction, the pin slot must be oriented towards the back cap.
Bring the gearbox in the neutral position
M ount a new gasket to ensure the back cap sealing.
Mount the back cap with the A groove in the primary shaft, and the oiling collector in the B
oil collecting groove, and tighten the screws at the required moment of 2,5 daNm .
Check the correct gears shifting.
Mount the reverse driving connector.
Mount the clutch control fork and the pressure bearing.
G earbox dismounting
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Replacement of the planetary
sealing gasket (on the vehicle)
SDV-uri SPECIALE NECESARE
C. V. 945 Mandrin montare garniturã etanºare planetarã
TIGHTENING MOMENTS (d aNm)
Shoc k absorber attachment
nut on steering knuckle 7.5
Wheel attachment screws 7.5
Oil draining plug 2.5
1
DISMOUNTIN G
Place the vehicle on a two-columns
elevator.
Dismount the right front wheel.
Drain the oil off the gearbox.
Dismou nt :
- the wheel protector
- the shock absorber attachment nuts
(1) on steering knuckle.
REMOUNTING
Lubricate with oil the new sealing gasket.
Mount the sealing gasket by means of the
C.V. 945 device.
M ount the protector (A) lubricated with
oil, on the planetary shaft and position the
gasket (C) by means of the device (B).
Rock the steering knuckle and disconnect
the planetary transmission from the gearbox.Remove
the “O” ring off the planetary shaft,
then, by means of a pins mandrel and a
hammer,
is gently hit in order to make it pivoting in its place.
Remove the sealing gasket by means of a
pliers, taking c are not t o damage the planetary
pinion grooves.
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Replacement of the planetary
sealing gasket (on the vehicle)
Position and mount the planetary transmission on the planetary pinion.
Perform the dismounting operations in the reverse order
Tighten at the required moment the screws and the nuts.
Perform the oil filling of the gearbox.
Check the gearbox sealing.
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