________________________________________________________________________________
Massey Ferguson 6480, 6485 power shuttle gearbox - Reverse clutch
Disassembling and reassembling the Massey
Ferguson 6485, 6480 tractor reverse clutch
Remove the MF 6480, 6485 forward clutch. Remove the input unit. Remove
the screws (70) and the cover plate (38). Recover the spools (44) and
the springs (45).
Remove the large springs (62) and the pins (71).
On the cover plate (38), remove:
- the plate (43),
- the seal (42) and discard it,
- the piston (39),
- the seals (36) (41) and discard them,
- the unions (72), the valve and the seal (75) from the 17 bar supply
port.
Immobilise the planet carrier (49) using the immobilizing tool.
Remove the screws (99) from the cover plate (34) and remove the cover
plate.
Remove the discs (47) and the intermediate plates (46).
Separate the output sun gear (58), held by the snap rings (61), from the
primary shaft (55).
Remove the snap ring (56).
Remove the planet carrier (49) with the double and single planet gears
(52) (59).
On the planet carrier (49), remove:
- the plates (63),
- the pins (50) and double planet gears (52) assembly Mark their
position,
- the pins (50) and single planet gears (59) assembly Mark their
position,
- the snap ring (98) and the bearing (57).
The rotation of the planet gears around the pins (50) is on two rows of
needle rollers (60), joined and separated by a spacer (51).
When the
planet gears and pins
have
been removed, check that no needle roller or spacer remains in the
planet carrier.
Clean and check all components. Replace those that are defective.
Check that the ports in the planet gear pins and the channels in the
planet carrier are not blocked.
Where necessary, Install the planet gears with two rows of needle
rollers smeared with miscible grease and separated by a spacer.
On the planet carrier, Install:
- bearing (57) and position the snap ring (98),
- double and single planet gears (52) (59) positioned,
- the pins (50), with the lubricating ports fitted facing those in the
planet carrier (49). Each end of the pins (50) has:
- a port, one of which is closed off by a rivet (35) and the other is
used to lubricate the planet gears;
- a flat section and a shoulder preventing any pin rotation or any side
movement.
Install the partially assembled planet carrier. Position the snap ring
(56) and the rear snap ring (61).
Position marks "R" (punch marks) on the double planet gears (52) so that
they pass through a centre line meeting at "O".
The mark on the front
face of the planet
gear corresponds to the alignment of two splines. It is mandatory to
correctly position the punch marks before assembling the output sun gear
(58).
Slide the output sun gear (58), correctly turned, on to the primary
shaft (55), making sure that the punch marks for each planet gear remain
in the required position.
Install the front snap ring (61).
Soak the discs (47) in a transmission oil bath for approximately 1 hour.
Check that they are correctly impregnated.
Install the discs (47) and the intermediate plates (46) depending on the
type of tractor.
Check that the centring pin (17) is present.
Install the cover plate (34). Check that it is correctly positioned on
the planet gear pins (50) and in the centring pin.
Immobilise the planet carrier, using the same method as used during
disassembly.
Install and tighten the screws (99)) to 36 - 46 Nm with its thread
lightly smeared with Loctite 242 or equivalent.
On the cover plate (38), check for the presence of the rivets (40) at
the end of the channels.
Install:
- piston (39) with new lubricated seals (36) (41), gradually and
alternately striking around the piston rim with a plastic hammer. Check
that there are no seal
fragments after fitting.
- plate (43) with a new lubricated seal (42), aligning the holes of the
plate with those in the cover plate (38). Install the plate using the
same method as used for the
piston (39).The thickness of the plate (43) differs according to the
number of discs and intermediate plates.
Install the pins (71) and the springs (62) in their respective locations
on the input unit.
Smear the spools (44) and the springs (45) with miscible grease. Fit and
fix the spools in each compartment of the cover plate (38), with the
tips facing towards the
unions. Slide and fix a spring (45) on each spool.
On the external face of the cover plate (38), fit three sufficiently
long and equally spaced studs in the holes provided for the screws (64).
Install and position the cover plate, with the port of the valve facing
upwards.
Before fitting the screws (70), it is mandatory to check that the spools
(44) slide freely in each compartment of the front cover plate on the
input unit. To do this,
compress the springs (45), using a screwdriver passed through the tapped
holes of the unions (72). If the springs cannot be compressed,
investigate the cause.
Pre-tighten the screws (70).
During pre-tightening, check that the spools (44) still slide freely.
Also check that each end of the (large) springs (62) is correctly housed
in its respective seat.
Tighten screws (70) to a final torque of 36 - 46 Nm. After completing the tightening, check again that each spool can move freely and returns to its initial position.
A
spool valve that is blocked open can restrict or interrupt lubrication
of the Massey Ferguson 6480, 6485 tractor forward clutch during
operation.
It is mandatory to fit and tighten the valve fitted with its seal to 6 -
8 Nm max. Screw in the unions (72).
Install the input unit and the forward clutch.
Disassembling and reassembling the driving gear and shimming the shaft
Remove the MF 6485, 6480 forward clutch. Remove the input unit. Remove
the reverse clutch. Remove the Speedshift unit.
Remove the screws (5) and the stop plate (8).
Recover the shims (3) and the cup (4).
Take out the secondary shaft (1), fitted with the bearing cone (6) and
the unit (7).
Note and mark the assembly order of the driving gear (2). Remove this
gear.
Recover the bearing cone (9). Extract the cup (10).
Check that the ports for the secondary shaft (1) and the housing
channels (7) are not blocked.
Clean and check all components. Replace those that are defective.
Lubricate the bearing cups and cones before assembling.
Install the cup (10) in the housing. Install the bearing cone (9) in this cup. Position the gear (2), correctly turned in the housing. Install the bearing cone (6) against the shoulder of the shaft (1).
Slide the shaft in through the gear (2) and the bearing (9).
Position the cup (4). Determine the thickness of shims (3) to obtain a
temporary clearance of approx. 0.10 to 0.15 mm for final shimming with
preload. Position the
shims and the stop plate (8). Tighten the screws to a torque of 25-32
Nm. Position the unit (7) in a vice.
Shimming the shaft
Place the dial gauge feeler pin on the end of the shaft.
Pull on the shaft, turning it alternately from right to left to
correctly "seat" the cones in the bearing cups.
Set the dial gauge needle to zero.
Depending on the clearance measured, select a new thickness of shims (3) to obtain a preload P1 so that: P1 = 0.05 to 0.15 mm. If possible, shim to the maximum tolerance. Remove the screws (5). Remove stop plate (8).
Position the final shims (3) selected on the unit (7). Install the plate (8). Install and definitively tighten the screws (5) to a torque of 25 - 35 Nm, with their threads lightly greased with Loctite 242 or equivalent.
Manually check the rotation of the shaft (1). Install the Speedshift unit. Install the reverse clutch. Install the input unit. Install the forward clutch.
________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________