Hydraulic 2/4 Wheel Drive Unit Disassembly And Assembly (Pressure On/Spring Off Type)7-53; Hydraulic 2/4 Wheel Drive Unit Disassembly And Assembly (Pressure On/Spring Off Type) - Manitowoc Grove 5540F Service Manual

5540F/YB5515 SERVICE MANUAL
Hydraulic 2/4-Wheel Drive Unit Disassembly
and Assembly (Pressure ON/Spring OFF
Type)
NOTE: Before disassembling the unit drain the gearbox oil.
To aid working on this item, use the output yoke as
a stand.
Dismantling, see Figure 7-91
1. Hold the yoke E using service tool 892/00812 and
remove bolt F. Remove the yoke. Carefully remove and
discard oil seal M. Be sure not to damage the seal
housing.
2. Remove bolts D. Lift off the 4WD casing P. Lift out the
4WD unit from the gearbox.
3. Remove bearing 1, only if to be renewed.
4. Remove seal ring 2. Note, If the piston ring seal is
damaged or excessively worn then check for burrs or
damage on the shaft groove. If necessary remove burrs
with a fine grade abrasion paper and oil.
5. Using a puller remove the 4WD output gear 5, together
with its bearing 3, needle roller bearings 6 and thrust
washer 4. Remove thrust washer 7. (Note that thrust
washers 4 and 7 are not interchangeable).
6. Remove circlip 8 and shim(s) 9 if fitted. Retain any shims
as a set for assembly.
7. Remove pressure plate 10, the clutch pack friction
plates 11 and counter plates 12.
NOTE: If only the clutch pack was to be removed, the job is
now complete.
8. Using a suitable press and an adaptor similar to Y,
compress spring 15 and remove circlip 13.
9. Remove spring retainer plate 14, spring 15 and oil baffle
15a.
10. Withdraw piston 16 then remove and discard O-rings 17
and 18.
NOTE: The piston housing cannot be separated from the
shaft, as on the other types of 2/4WD units.
Inspection
Perform a visual inspection of the friction and counter plates.
Counter plates - light scoring/polishing is permissible, plates
that are not flat, worn or heavily marked or scored must be
replaced with a new set.
Friction plates - the cross hatching should be clearly visible,
plates that are not flat, have friction material damage or
scoring must be replaced with a new set.
Do not mix old, new and worn plates.
GROVE
TRANSMISSION AND TORQUE CONVERTER
Two different suppliers of the thinner friction plates 0.062 to
0.067 in (1.6 to 1.7 mm) approximately have been used
(identified as brown or green), do not mix the different plates
in the same clutch pack.
Inspect the mating faces of the gearbox and 4WD casings for
damage.
Assembly
If only the clutch pack has been removed, begin at step 4.
1. Grease the shaft, fit new O-rings 17 and 18 then locate
piston 16 over the shaft and into the housing.
2. Locate oil baffle 15a, spring 15 into the piston and
position the retainer plate 14 over the spring.
3. Using a press and adaptor Y, compress spring 15 and fit
circlip 13.
4. Build up the clutch pack, installing friction plates 11 and
counter plates 12 alternately, starting with a counter
plate and ending with a friction plate.
5. Install pressure plate 10, shim(s) 9 and circlip 8. Using
an air line blow air down the shaft oil inlet hole and check
the piston and clutch pack is free to operate smoothly.
6. Measure the clutch pack end float using two
screwdrivers as shown at B. End float should be
between 0.04 to 0.09 in (1.0 mm to 2.3 mm). Adjust as
necessary, by adding or removing shims 9.
7. Fit thrust washer 7, 4WD gear 5, needle roller bearings 6
and thrust washer 4.
8. Press bearing 3 squarely onto the shaft to seat on thrust
washer 4, taking care not to exert any force on the
housing i.e. rest the unit on the opposite shaft end, not
the housing.
9. Fit new seal 2.
10. If required, press a new bearing 1 into position, taking
care not to exert any force on the housing (see Step 8).
11. Fit the 2/4WD unit to the gearbox.
12. Apply a thin bead of Loctite 574 Multi gasket to the 4WD
mating face of the gearbox front case. Fit the case P,
apply Loctite 242 to bolts D and progressively torque to
46 Ib ft (56 Nm).
13. The 2/4WD unit and its associated components are
manufactured using a 'set-right' system. Provided that
components have been assembled correctly, the shaft
end float will be 0.0004 to 0.006 in (0.01 to 0.16 mm).
Rotate the shaft by hand and ensure that it runs
smoothly. Pull the shaft up and down to detect any
excessive end float. If there is excessive end float or the
shaft runts roughly, dismantle the unit and check for
correct assembly.
Published 10-21-2010, Control# 198-04
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