Caterpillar Cat 988G Wheel Loader (Prefix 2TW) Service Repair Manual (2TW00001 and up)

1
Service Repair Manual
Models 988G Wheel Loader
2
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Product WHEEL LOADER Model 988G WHEEL LOADER
2TW Configuration 988G Wheel Loader 2TW00001-UP
(MACHINE) POWERED BY 3456 Engine
Disassembly and Assembly 988G Wheel Loader Power
Train Media Number -RENR3096-11 Publication Date
-01/05/2011
Date Updated -25/05/2011
i05870306
Torque Converter - Disassemble SMCS -
3101-015 Disassembly Procedure Table 1
Required Tools Required Tools Required Tools Required Tools
Tool Part Number Part Description Qty
A 138-7573 Link Bracket 1
A 138-7575 Link Bracket 2
B 138-7575 Link Bracket 2
C 8B-7548 Push-Puller Tool Gp 1
C 8H-0684 Ratchet Wrench 1
C 8B-7549 Puller Leg 2
C 5P-4808 Cap 2
C 8B-7554 Bearing Cup Puller 1
D 5F-7366 Screw 1
D 3H-0465 Plate 2
D 1P-5546 Crossblock 1
D 5H-7369 Puller Leg 2
D 8B-7551 Bearing Puller 1
D 6B-6682 3/4" - 16 NF Nut 2
D 1P-0520 Driver Gp 1
3
5F-7366 Screw 1
3H-0465 Plate 2
1P-5546 Crossblock 1
8B-7549 Puller Leg 2
5F-7343 Bearing Puller 1
6B-6682 3/4" - 16 NF Nut 2
1P-0520 Driver Gp 1
5F-7342 Adapter 2
F 138-7574 Link Bracket 2
G - Forcing Screw M12 x 1.75 2

• Start By
• Remove the torque converter. Refer to Disassembly
  and Assembly, "Torque Converter - Remove" for
  the machine that is being serviced.
• Remove the transmission oil pump. Refer to
  Disassembly and Assembly, "Transmission Oil
• Pump - Remove" for the machine that is being
  serviced.
• Remove the torque converter outlet relief valve.
  Refer to Disassembly and Assembly, "Relief Valve
  (Torque Converter Outlet) - Remove" for the
  machine that is being serviced.
• Remove the modulating valve for the torque
  converter impeller clutch. Refer to
• Disassembly and Assembly, "Modulating Valve
  (Torque Converter Impeller Clutch) - Remove" for
  the machine that is being serviced.

Illustration 1 g00660840 1. Place the torque
converter assembly (1) on suitable cribbing, as
shown. The weight of torque converter assembly
(1) is approximately545 kg (1200 lb).
4
Illustration 2
g00665406
2. Remove bolt (2) and retainer (3) .
Illustration 3
g00665411
3. Remove O-ring seal (4) and yoke (5) .
Illustration 4
g00665412
4. Remove bolts (6) and the washers.
5

• Illustration 5 g01152195
• Install Tooling (A) and a suitable lifting device
  to the housing assembly. The weight of the
  housing assembly is approximately 285 kg (630
  lb).
• Use Tooling (G) in order to separate the housing
  assembly from the torque converter.
• Remove the housing assembly.

Illustration 6
g00660846
8. Remove bolts (7) and retainer (8) .
6
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Illustration 7
g00660847
9. Remove seal (9) from retainer (8) .
Illustration 8
g00660849

1. Remove gasket (10) .
2. Remove O-ring seals (11) and (12) .

Illustration 9
g00665426
8
Illustration 10 g00665427 12. Remove bolts (13)
. Do not remove two bolts (14) at this time.

• Illustration 11 g00660851
• Install Tooling (B) and a suitable lifting device
  to carrier assembly (15) . The weight of carrier
  assembly (15) is approximately 160 kg (350 lb).
• Remove carrier assembly (15) and the shaft as a
  unit.

9
Illustration 12
g00660854

1. Remove bearing (16) .
2. Remove the ring and the plate below bearing (16) .

Illustration 13
g00660856
17. Remove turbine (17) .
Illustration 14
g00660858
10

1. Remove the plate (not shown) and remove bearing
   (18) .
2. Remove the ring and the plate below bearing (18) .

Illustration 15
g00660859
20. Remove bearing cup (19) .

• Illustration 16 g01152217
• Use appropriate equipment in order to turn
  housing (20) onto the opposite side.
• Remove O-ring seal (21) and two plugs (22) .

11

• Illustration 17 g01152220
• Remove bolts (23) and the washers from turbine
  (17) .
• Remove plate (24) .
• Remove hub (25) from turbine (17) .

Illustration 18 g00662857 26. Place torque
converter assembly on suitable cribbing, as shown.
12
Illustration 19 g00662858 27. Remove retaining
ring (26) and stator (27) .
Illustration 20
g00662860

1. Remove spacer (28) .
2. Remove bearing (29) .
3. Remove the plate and the ring below the bearing
   (29) .

Illustration 21
g00662862

1. Remove retaining ring (30) .
2. Use two persons in order to remove impeller (31)
   . The weight of impeller (31) is approximately
   30 kg (65 lb).

13
Illustration 22 g03389696 33. Remove plate (32a)
, bearing (32b) , plate (32c) , and ring (32d)
. Note Plate (32a) may stick to the impeller.
Illustration 23 g00662864 34. Remove bearing cup
(33) from impeller (31) .
Illustration 24
g00662866
14

1. Remove bolts (34) and the washers.
2. Remove impeller (31) from adapter assembly (35) .

Illustration 25
g00662867

1. Remove bolts (14) .
2. Remove plate (36) .

Illustration 26 g00662868 39. Remove two
friction discs (37) and one wear plate.
15
Illustration 27
g00662869
40. Remove piston (38) .
Illustration 28 g00662871 41. Use two persons in
order to remove housing assembly (39) from shaft
(40) . The weight of housing assembly (39) is
approximately 45 kg (100 lb).
Illustration 29
g00662872
16
42. Remove 12 bolts (41) and gear (42) from
housing assembly (39) .
Illustration 30
g00663774
Typical Example
Illustration 31 g00662873 43. Remove bearing cup
(43) from gear (42) .
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Illustration 32
g00662877

1. Remove bolts (44) and sleeve (45) .
2. Remove the ring seal from sleeve (45) .
3. Remove ring seal (46) .

Illustration 33
g00663023

1. Remove seal (47) .
2. Remove seals (48) .
3. Remove ring (49) .

18
Illustration 34 g00663084 50. Place shaft
assembly in a suitable press. Carefully press
inner shaft (50) from outer shaft (51) .
Illustration 35 g00663095 51. Use a suitable
press in order to remove bearing (52) and seal
carrier (53) from inner shaft (50) .
Illustration 36
g00663096
19
52. Use a hammer and a punch in order to remove
pin (54) from outer shaft assembly (51) .
Illustration 37 g00663097 53. Use Tooling (D) in
order to remove seal carrier (55) from outer
shaft (51) .
Illustration 38 g00663098 54. Use Tooling (E) in
order to remove bearing (56) from outer shaft
(51) .
20
Illustration 39 g00663100 55. Remove retaining
ring (57) and plate (58) from stator (27) .
Repeat this procedure for the opposite side.
Illustration 40
g00663101
Illustration 41
g00663781
56. Remove retaining ring (59) .
21

1. Place stator (27) in a suitable press, as shown.
2. Remove adapter (60) from stator (27) .

Illustration 42
g00663255
59. Remove bolts (61) .

• Illustration 43 g00663256
• Install bolts (61) as forcing screws. Attach
  Tooling (F) and a suitable lifting device to
  adapter (62) . The weight of adapter (62) is
  approximately 30 kg (65 lb).
• Remove adapter (62) .

22
Illustration 44 g00663257 62. Remove O-ring
seals (63) from adapter (62) .
Illustration 45 g00663261 63. Remove bearing cup
(64) and seal (65) from adapter (62) .
Illustration 46
g00663265
64. Remove gear assembly (66) .
23
Illustration 47 g00663268 65. Use Tooling (D) in
order to remove bearing cone (67) from gear
assembly (66) .
Illustration 48 g00663276 66. Remove retaining
ring (68) and adapter (69) from gear assembly
(66) .
24
Illustration 49 g00663279 67. Remove retaining
ring (70) from adapter (69) . Remove plate (71) .
Illustration 50 g00663311 68. Use Tooling (D) in
order to remove bearing cone (72) from gear
assembly (66) .
Illustration 51 g00663620 69. Remove shim pack
(73) and bearing cup (74) .
25
Illustration 52
g00663622
70. Remove three bolts (75) and cover (76) .
Illustration 53 g00663623 71. Remove O-ring seal
(77) from cover (76) .
Illustration 54
g00663624
72. Remove bolt (78) and the washer.
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73. Remove idler gear shaft (79) .
Illustration 55
g03410188
If equipped with this style lube adapter.
Illustration 56
g03410201
If equipped with this style lube adapter. 74.
Remove lube adapter (79a) , (79b) .
27
Illustration 57
g00663626
75. Remove idler gear assembly (80) .

• Illustration 58 g00663627
• Remove bearing assemblies (81) and ring (82) from
  idler gear assembly (80) .
• Repeat steps 59 through 76 in order to remove the
  remaining pump adapter.

Illustration 59
g00663628
28
78. Remove bolts (83) and block (84) .
Illustration 60
g00663671
79. Remove O-rings (85) and plugs (86) .
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29
Shutdown SIS
Previous Screen
Product WHEEL LOADER Model 988G WHEEL LOADER
2TW Configuration 988G Wheel Loader 2TW00001-UP
(MACHINE) POWERED BY 3456 Engine
Disassembly and Assembly 988G Wheel Loader Power
Train Media Number -RENR3096-11 Publication Date
-01/05/2011
Date Updated -25/05/2011
i02112056
Torque Converter - Assemble SMCS -
3101-016 Assembly Procedure Table 1
Required Tools Required Tools Required Tools Required Tools
Tool Part Number Part Description Qty
A 138-7573 Link Bracket 1
A 138-7575 Link Bracket 2
B 1P-0520 Driver Gp 1
C 188-1456 Metric Eyebolt 1
D 138-7575 Link Bracket 2
E 138-7575 Link Bracket 3
F 1P-0520 Driver Gp 1
F 8T-5096 Dial Indicator Gp 1
Note Cleanliness is an important factor. Before
assembly, all parts should be thoroughly cleaned
in cleaning fluid. Allow the parts to air dry.
Wiping cloths or rags should not be used to dry
parts. Lint may be deposited on the parts which
may cause later trouble. Inspect all parts. If
any parts are worn or damaged, use new parts for
replacement. Note Apply oil to all of the
bearings before assembly. 1. Check the condition
of the O-ring seals that are used in the torque
converter and torque converter housing. If any
of the seals are damaged, use new parts for
replacement.
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Illustration 1 g00674989 2. Install five O-ring
seals (96) and three plugs (97) .
Illustration 2
g00674987
3. Install block (95) and four bolts (94) .
Illustration 3
g00674791
31
4. Install seal (71) onto piston (70) .
Illustration 4
g00674790
5. Install piston (70) .
Illustration 5
g00674788
Illustration 6
g00674750
32
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6. Install two wear plates (68) and two friction
discs (69) .
Illustration 7
g00674748
7. Install plate (67) and retaining ring (66) .
Illustration 8
g00674744
Illustration 9
g00674747
34

1. Install clutch adapter (65) and hub (63) to
   turbine (64) .
2. Install 24 bolts (62). The torque for bolts (62)
   is 105 15 Nm (77 11 lb ft).

Illustration 10
g00674727
10. Install bearing (61) .
Illustration 11 g00674725 11. Install O-ring
seal (59) and two plugs (60) .
35

• Illustration 12 g00675696
• Use the appropriate equipment in order to turn
  the housing assembly onto the opposite side, as
  shown.
• Install turbine assembly (64) into housing
  assembly.

• Illustration 13 g00675769
• Install the ring and the plate below bearing (58)
  .
• Install bearing (58) .

36
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Friend! Thank you very much for visiting. Full
manual if required, please enter the following
URL into your browser. https//www.aservicemanual
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