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Repair of Case 1194,1294 Tractor 12-speed Synchromesh transmission
Disassembly Operations
Fig.18. Case 1194, 1394, 1490, 1294, 1594 Tractor 12-speed
synchromesh transmission
1.Snap ring, 2.Snap ring, 3.Bearing, 4.Snap ring, 5.Inner sparer,
6.Outer spacer, 7.Bearing, 8.Input gear, 9.Sealing ring, 10.Slow/normal
sliding gear, 11.Snap ring, 12.Bearing, 13.Spacer, 14.Snap ring,
15.Bushing, 16.High/law sliding gear, 17.Input shaft, 15.Bushing
surface, 19.Bushing, 20.Reverse idler gear, 21.Retaining washer, 22.Tab
washer, 23.Bolt, 24.Thrust washer, 25.Bearing, 26.Snap ring, 27.Locknut,
28.Wisher, 29.Bearing, 30.Spacer, 31.Front end housing, 32.Snap ring,
33.Shims, 34.Thrust washer, 35.Bearing pad, 36.Snap ring,
37.Synchronizer, 38.Second gear, 39.Retaining washer, 40.Split rings,
41.Shim, 42.Rear end housing, 43.Bushing, 44.Shim, 45.Mounting bolt,
46.Shoulder spacer, 47.Washer, 48.Third gear, 49.Front synchronizer
gear, 50.Synchronizer spring, 51.Bearing pad, 52.First/reverse sliding
gear, 53.Bearing, 54.Pinion shaft, 55.Shift interlock, 56.Center
housing, 57.Second/third shift rod, 58.First/reverse shift rod, 59.Idler
shaft, 60.Roll pin, 61 Plug, 62.Thrust washer, 63.Bearing, 64.Spacer,
65.Idler gear, 66.Bearing, 67.Thrust washer, 68.Bearing,
69.Countershaft, 70.Bearing, 71.Shim, 72.Slow/normal shift rod,
73.High/low shift rod, 74.Shift fork, 75.Selector jaw, 76.Sleeve
Place transmission in a suitable transmission support stand, then remove
roll pins from slow/normal shift fork (74) and selector jaw (75). Push
slow/normal shift rod (72) rearward just far enough to remove detent
ball and spring. Remove shift rod, selector jaw and shift fork.
Remove high/low shift fork, sleeve, detent ball and spring and shift rod
(73). Remove roll pins from shift fork and selector jaw on second/third
shift rod (57) and move rod toward rear of transmission just enough to
remove detent ball and spring. Remove shift interlock plug (55).
Noting pinion nut (27) has left-hand threads, remove nut (27), washer
(28) and bearing cone (29) from pinion shaft (54). Remove stud bolt
nuts, then separate and support front end housing (31) approximately 40
mm (1.5 inches) from transmission center housing (56).
Push first/reverse shift rod (58) rearward just enough to remove detent
ball and spring. Lift front end housing (31) off Case 1194, 1294 Tractor
transmission center housing (56). Remove slow/normal sliding gear (10)
from inside front end housing.
Remove roll pin (60) and remove idler shaft (59). Remove snap ring (1)
from input gear (8) and snap ring (2) from front end housing (31).
Carefully remove input gear assembly out of front end housing. Do not
use force as damage to bearings may result. Remove idler gear (65) and
both thrust washers (62 and 67).
Remove bearings (63 and 66) and spacer (64) from inside idler gear (65).
Remove input gear bearing cup and outer spacer (6) from front end
housing. Remove remaining bearing cups, spacer, bearings and snap rings
as necessary.
Remove stud bolts. Remove center housing (56) by rotating center housing
towards countershaft to gain clearance, then lift housing over shaft and
gear assemblies.
Remove countershaft (69) from rear end housing (42). Remove retaining
bolt (23), remove high/low shift fork from sliding gear (16), and remove
input shaft assembly (17) from rear end housing. Use care not to lose
retainer (21).
Remove snap ring (26) and press rear bearing (25), thrust washer (24)
and reverse idler gear (20) off together. Move snap ring (14) away from
bearing (12) and press bearing and spacer (13) off input shaft (17).
Remove snap ring (14) and high/low sliding gear (16). Remove bushing
(15) from inside input shaft.
Remove second/third shift fork from synchronizer (37). Remove shoulder
spacer (46), shims (33), spacer (47) and third gear thrust washer (34).
Remove third gear (48) and the six bearing pads (35). Remove
synchronizer (37) and front synchronizer gear (49). Remove snap ring
(36) and gear synchronizer gear (not shown).
Remove second gear (38), the six bearing pads (51), split ring retainer
washer (39) and split rings (40). Remove first/reverse sliding gear (52)
and shift rod assembly together.
If pinion shaft (54) is to be renewed, mark differential bearing cap
positions and remove differential assembly. Remove pinion shaft rearward
from housing.
Inspection
Clean and inspect all parts. Examine bearings and bushings for wear or
damage and renew as necessary. If gear teeth show excessive wear or
irregular wear pattern, gear should be renewed along with its mating
gear.
Examine synchronizer friction surfaces and the synchronizer pads (35 and
51) for wear. Slight looseness of pads in synchronizer is normal and the
pads should slide easily into their grooves with no binding. No attempt
should be made to disassemble synchronizer assembly as individual
service parts are not available.
Fig.19
Examine fit of detent balls in grooves of shifter rails. Shift rail
grooves should have straight 60 degree sides and detent ball must not
contact bottom of groove. Check all thrust washers and spacers for
excessive wear or damage and renew as necessary.
If pinion shaft, bearings, end housings or center housing are renewed,
pinion shaft protrusion must be set before reassembling Case IH 1194,
1294 Tractor transmission.
Pinion shaft assembly
Install:
- pinion shaft and rear bearing sliding gear (16) on input shaft with
larger diameter gear toward rear end of shaft. Heat front bearing (12)
to 120°C (250°F) maximum, then install snap ring (14), spacer (13) and
bearing on shaft. Note that bearing must be installed with side stamped
with bearing numbers towards front end of shaft.
Press new bushing (19) into reverse idler gear (20), then install gear
onto input shaft with beveled edge of gear teeth towards front of shaft.
- thrust washer (24) with flat side towards idler gear. Heat rear
bearing (25) to 120°F (250°F) maximum, then install bearing and snap
ring (26).
PPosition shaft assembly on rear housing and install retaining washer
(21), tab washer (22) and bolt (23). Tighten bolt to 11 N-m (8 ft.-lbs.)
torque, then bend tab washer against bolt head.
Input shaft assembly
Install:
- new bushing (15) into front end of input shaft (17). Place high/low
into rear housing. Position first/reverse shift fork into slot in
sliding gear (52), then install gear over
pinion shaft. Make certain shift rod enters hole nearest input shaft
retaining washer.
- split rings (40) and retaining washer (39).
- second gear (38) with synchronizer ring towards front end of shaft.
Lightly coat bearing pads (51) with grease, then install pads in pinion
shaft splines under second
gear.
- rear synchronizer gear so end of gear with alignment marks is towards
second gear.
- snap ring (36), align marks of rear synchronizer gear with marks on
front synchronizer gear.
- front gear (49) with slotted end of gear towards front of shaft.
- synchronizer (37).
- third gear (48) with synchronizer ring towards synchronizer. Apply
small amount of grease to bearing pads (35), then install pads behind
third gear.
- thrust washer (34) and fiat spacer (47). Do not install shims (33) or
shoulder spacer (46) at this time.
Countershaft assembly
Heat front and rear hearings (68 and 70) to 120°C (250°F) maximum, then
install on countershaft (69).
To adjust end play, remove a shim 0.25 mm (0.010 inch) in thickness from
original shim pack (71).
Install:
- remainder of shims and bearing cup in rear housing.
- front bearing cup in bore of front housing. Position countershaft on
rear housing.
- center housing, stud bolts and front housing and tighten stud bolt
nuts to 95 Nm (70 ft.-lbs.) torque. Mount a dial indicator so probe
contacts rear gear of countershaft.
Move shaft up and down and measure end play. Disassemble housings and
countershaft. Remove rear bearing cup and shims. Subtract 0.076 mm
(0.003 inch) from
end play measurement. The result is thickness of shims that must be
added to original shim pack to obtain specified end play of 0.076 mm
(0.003 inch).
- required thickness of shims and reinstall bearing cup. Position
countershaft on rear housing.
Center and front housing assemblies
To install:
- center housing (56), place second/third gear selector fork into groove
on synchronizer (37). Put high/low selector fork into groove on sliding
gear (16).
- center housing turning the housing to clear countershaft gears. Apply
Loctite 242 to stud bolt threads, then install stud bolts into rear
housing and tighten to 122 N-m
(90 ft.-lbs.) torque. Heat bearing (7) to 120°C (250°F) maximum, then
install on input gear (8). Be sure side of bearing stamped with bearing
numbers is towards
splined end of gear.
- inner spacer (5) on input gear.
- snap ring (4), bearing (3) and snap ring (2) in front housing (31).
- outer spacer (6) and outer bearing race for roller bearing in front
housing. Assemble bearings (63 and 66) and spacer (64) in range idler
gear (65). Use a depth
micrometer to measure distance needle bearing cage is below free of
idler gear. The distance must be 0.25-1.27 mm (0.010-0.050 inch). If
distance is not within the
specified range, check for worn needle bearings. Renew spacer if spacer
length is less than 42.545 mm (1.675 inches).
- assembled range idler gear and thrust washer (62 and 67) in front
housing with larger gear towards front of the housing.
- input gear assembly in front housing and install snap ring. Clean oil
passage in idler gear shaft (59), apply Loctite 242 to threads of plug
(61) and install plug in shaft.
Align roll pin hole in idler shaft and front housing.
- install shaft through idler gear and roll pin. Assemble snap ring
(32), spacer (30) and pinion shaft front bearing cup into bore in front
housing.
- front housing assembly and support housing approximately 40 mm (l'/a
inches) above center housing. Place slow/normal sliding gear (10) on
rear input shaft (17)
with selector fork groove towards input gear. Remove spacers, then lower
front housing until first/reverse shift rod (58) enters hole in front
housing.
- detent ball and spring using tool while joining front housing and
center housing.
- new locknuts on housing studs and tighten to 95 N-m (70 ft.-lbs.)
torque.
Shift rods and detents
Install:
- high/low shift rod (73) and spacer (76). Install detent spring and
ball using tool.
- roll pin in shift fork.
- slow/normal shift rod (72), shift fork (74), spacer and selector
jaw(75).
- detent spring and ball using assembly tool, then install roll pins in
fork and selector jaw.
- second/third shift rod making certain end with neutral start switch
groove is toward rear of transmission. Push rod through shift fork
slightly.
- selector jaw with flat side toward first/reverse selector jaw.
- shift interlock plug (55) and detent ball and spring.
Engage third gear and install roll pin in second/third selector jaw.
Engage second gear and install roll pin in second/third shift fork.
Pinion shaft bearing preload
Install:
- original shims (33) removed during disassembly plus an additional 0.25
mm (0.010 inch) thick shim.
- shoulder washer (46) with flat side against shims (33).
- bearing cone (29), washer (28) and nut (27). Note that nut has
left-hand threads and tighten to 270 N-m (200 ft.-lbs.) torque. Mark
differential bearing caps and
remove differential assembly if not already removed. Mount dial
indicator so probe contacts end of pinion shaft, then measure and note
amount of pinion shaft end
play.
Remove nut (27), washer (28), bearing (29) and shoulder washer (46).
Remove thickness of shims (33) 0.05 mm (0.002 inch) greater than amount
of measured end
play to obtain specified bearing preload of 0.05 mm (0.002 inch).
Reinstall spacer, bearing, washer and nut. Tighten nut to 270 N-m (200
ft.-lbs.) torque. Reinstall
differential assembly and adjust backlash.
Shift transmission and range section through all gears and check to be
certain all gears and detents work properly.
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CASE IH TRACTORS SPECIFICATIONS |
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CASE IH FRONT END LOADERS SPECS |
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