Power shift transmission - overhaul


REMOVE PLANETARY ASSEMBLIES   

Front planetary assembly of power shift transmission

1.Input shaft, 2.Clutch cylinder, 3."O'ring, 4.Spring, inner, 5.Clutch plate steel ,6.Locknut, 7.Conical washer, 8.Seal, 9.Clutch plate bronze, 10.Backing plate, 11.Carrier & cylinder, 12.Planet gear, 13.Needle roller bearing    , 14.Bearing pin, 15.End cover, 16.Bearing, 17.Spacer plate, 18.Sprag clutch, 19.Sealing rings, 20.Support tube, 21."O" ring, 22.Seal, 23.Front cover, 24.Bushing, 25.Support sleeve, 26.Sealing rings, 27.Bearing, 28."O" ring, 29.Piston, 30.Spring, outer, 31.Thrust washer, 32.Bushing, 33.Washer, 34.Snap ring, 35.Cylinder, 36.Piston, 37.Locknut, 38.Spherical washer, 39.Sleeve, 40.Spring, 41.Seat, 42.Brake hand, 43.Sun gear, 44.Dowel, 45.Thrust washer, 46.Bearing carrier, 47.Locating screw, 48.Center carrier

Remove  support sleeve (20) and front cover (23). Disconnect brake line from front planetary brake cylinder (35) and remove cylinder. Loosen front brake band locating screws and remove brake band adjusting nuts (6 and 37). Remove sleeve (39), spring (40) and seat (41). Withdraw input shaft (1), then remove brake band (42) and lift front planetary unit from center housing. Remove hydraulic line for planetary brake cylinder from center carrier. Remove spacer plate (17) and sprag clutch (18).
Turn center housing over, then remove rear brake band and rear planetary assembly (Rear planetary) from housing in same manner as front unit. Unbolt and remove bearing carrier (46—Front planetary) from center housing. Remove spacer (20-Rear planetary), sprag clutch (21) and carrier (42) from rear end housing (43) if necessary.

FRONT PLANETARY OVERHAUL

Mark clutch cylinder (2—Front planetary), carrier (11) and end cover (15) so they can be reassembled in their original positions. Remove mounting bolts, then separate clutch cylinder from planetary carrier. Remove piston (29) from cylinder and remove and discard "O" rings (3 and 28). Remove inner and outer springs (4 and 30). Remove clutch plates (5, 9 and 10) keeping plates together for use in reassembly.
Clutch plates are a matched set and are not available separately.
Use a hoist and chain to support power shift unit as shown when removing and Installing unit from range gearbox.

Remove retaining bolts and separate end cover (15) from carrier (11). Mark position of planetary gears (12) and gear pins (14) for proper reassembly, then remove from end cover.
Clutch plates must be free of cracks, distortion or excessive wear. Renew plates as necessary. Inspect springs (4 and 30) and renew if distorted or weak. Check thrust washer, bearings and planetary gears for wear or damage and renew as necessary.
Lubricate "O" rings (3 and 28) and install on piston (29). Carefully install piston into cylinder. Position inner springs in clutch piston and hold in place with petroleum jelly or grease.

Install
- planetary gear pins, bearings and gears in their original positions with gear timing marks pointing toward center of carrier. 
- sun gear aligning timing marks as shown. 
- thrust washer (45— Front planetary), with oil groove facing up, into end cover (15). 
- end cover over planetary gears aligning marks made during disassembly. Tighten mounting bolts to 40 Nm (30 ft.-lbs.) torque and secure with locking plates. Assemble thick clutch backing plate (10), slotted bronze clutch plate (9), thin steel spacer plate , it remaining slotted bronze plate (9) and thin steel plate (5) onto clutch carrier (11). 
- outer springs in carrier. 
- clutch cylinder (2) with piston and inner springs onto carrier aligning marks made during disassembly. Tighten mounting bolts to 27 N-m'(20 ft.-lbs.) torque and secure with locking plates.

REAR PLANETARY OVERHAUL

Rear planetary assembly of power shift transmission

1.Center carrier, 2.Thrust washer, 3.Rear input shaft, 4.Bearing, 5.Carrier & cylinder, 6."O" ring, 7.Piston, 8.Spring inner, 9.Clutch plate steel, 10.Conical washer, 11.Locknut, 12.Taper plug, 13.Stop screw, 14.Locknut, 15.Planet gear, 16.Needle roller bearing, 17.Bearing pin, 18.Spacer, 19.Bearing, 20.Spacer plate, 21.Sprag clutch, 22."O" ring, 23.Spring outer, 24.Thrust washer, 25.Brake band, 26.Locknut, 27.Washer, 28.Snap ring, 29.Cylinder, 30.Piston, 31.Spherical washer, 32.Sleeve, 33.Spring, 34.Seat, 35.Clutch plate bronze, 36.Backing plate, 37.Carrier & cylinder, 38.Sun gear, 39.Dowel pin, 40.Thrust washer, 41.End cover, 42.Carrier, 43.End housing, 44.Case

Mark clutch cylinder (5—Rear planetary), carrier (37) and end cover (41) so they can be reassembled in their original positions. Remove clutch cylinder mounting bolts and separate planetary halves. Remove inner and outer springs (8 and 23). Remove piston (7) from cylinder and remove and discard "O" rings (6 and 22),
Lift input shaft (3) and clutch plates (9, 35 and 36) from carrier keeping plates together for reassembly. Clutch plates are a matched set and are not available separately. Remove mounting bolts and separate end cover (41) from carrier. Mark position of planetary gears (15), bearing pins (17) and dowels (39) for reassembly, then remove sun gear and planetary gears. Remove thrust washer (40) from sun gear. Use a suitable puller to remove bearings (4 and 19).
Clutch plates must be free of cracks, distortion or excessive wear. Renew springs (8 and 23) if distorted or weak. Inspect thrust washers, bearings, bearing pins and planetary gears for excessive wear or damage and renew if necessary.

Install
- new bearing (4—Rear planetary) on clutch cylinder (5), Lubricate "O" rings (6 and 22) and install on piston, then carefully install piston into cylinder. 
- inner springs (8) and apply grease to hold springs in position during assembly.

Planet gears must be timed as shown with punch marked tooth of each gear pointing towards canter of sun gear

- bearing pins (17) in carrier (37) making sure they are in their original positions. Assemble a short bearing (16), thrust washer (18) with oil groove facing away from short bearing and a long bearing onto bearing pins. 
Install planetary gears on their original pins with gear timing marks pointing toward center of carrier. Place thrust washer in sun gear counter bore with oil groove side of washer facing up. 
- sun gear with thrust washer towards carrier aligning timing marks. 
- new bearing (19—Rear planetary), if removed, on end cover (41) and position thrust washer (40) in cover. Position end cover over planetary gears aligning assembly marks made during disassembly. Tighten mounting bolts to 40 N-m (30 ft-lbs.) torque and secure with locking plates.
- input shaft (3) into planetary assembly.

Install backing plate, grooved bronze clutch plates, smooth bronze clutch plate and thin steel clutch plates for rear planetary clutch In sequence shown

1.Cylinder assy, 2.Thin steel clutch plates, 3.Backing plate, 4.Carrier, 5.Grooved bronze clutch plate, 6.Smooth bronze clutch plate

- thick backing plate (3) into carrier (4). There are four thin steel clutch plates (2), three grooved bronze clutch plates (5) and one smooth bronze clutch plate (6). To assemble plates in carrier, place one grooved bronze plate on top of backing plate, then one thin steel plate, another grooved bronze plate, a thin steel plate, then the smooth bronze plate, a thin steel plate, a grooved bronze plate and remaining thin steel plate last.
- outer clutch springs (23—Rear planetary). Align assembly marks and install cylinder (5) on carrier. Tighten mounting bolts to 27 N-m (20 ft.-lbs.) torque, then bend corners of locking plates against bolt heads.

CENTER CARRIER AND FRONT COVER

Inspect sealing rings (19—Front planetary) in bearing carrier (46) and renew as necessary.
Position thrust washer in carrier counter bore with oil groove facing up. Install sealing rings in carrier grooves with chamfered side up on top ring and down on bottom ring. Stagger ring end gaps 180° from each other.

Sealing rings must be installed in center carrier with Inside chamfer up on top ring and Inside chamfer down on bottom ring. Ring gaps must be 180° from each other

When reinstalling carrier in center housing, make certain lubrication holes are in alignment. Tighten carrier mounting bolts to 40 N-m (30 ft.-lbs.) torque. Lubricate seal rings with transmission fluid prior to reassembly.
Renew thrust washer (31 —Front planetary), bushing (32) and oil seal (8) in front input shaft (1) if necessary. Be sure to install thrust washer with oil groove side towards gear.
Pry oil seal (22—Front planetary) from front cover (23). Remove seal rings (26) from front support sleeve (25). Remove sleeve mounting bolts and remove sleeve from front cover if renewal of bushing (24) is necessary.

Install
- new bushing (24) flush with inner face of support sleeve (25), Apply gasket sealer to mounting surface of sleeve, then install and tighten bolts to 20 N-m (15 ft.-lbs.) torque. 
- sleeve sealing rings (26) with chamfered side up on top ring and chamfered side down on bottom ring. 
- new front oil seal (22-Front planetary) with lip facing inward.

REINSTALL PLANETARY ASSEMBLIES

View of rear planetary brake band and housing showing location of the four locating screws

Be sure brake band locating screws are in place in center housing. 
- rear brake band in housing, then position rear planetary in center carrier.

View of front planetary brake band and housing showing correct position of the three locating screws

- sprag clutch into center bearing carrier with wide edge facing inward. Position spacer over sprag clutch. 
- front planetary brake hydraulic line. 
- front planetary unit into carrier rotating unit clockwise during installation.  
front brake band.
- front cover and tighten mounting bolts to 20 N-m (15 ft.-lbs.) torque. 
- new "O" rings (21—Front planetary) on support sleeve (25) and tube (20). Position support tube (20) on front cover so oil hole in tube is towards bottom of power shift housing and tighten mounting bolts to 12 N-m (9 ft.-lbs.) torque.
- brake band springs and adjusting nuts. Tighten adjusting nut on spring end of band until spring length is 33.33 mm if new bands were installed, or 35 mm if old bands are being reused. 
- brake piston and cylinder and tighten mounting bolts to 23-28 N-m (17-20 ft.-lbs.) torque. Connect brake hydraulic lines. Turn brake band locating screws clockwise until they contact brake bands, then turn rear band locating screws counterclockwise turn and turn front band locating screws counterclockwise turn. Tighten locknuts to secure locating screw adjustment.
Final planetary brake band adjustment must be made with tractor running .

PLANETARY BRAKE BAND ADJUSTMENT

Planetary brake bands provide braking on overrun, and wear will be indicated by delay in shifting down or failure to hold in gear. Brake bands may be adjusted if not worn beyond limits of adjustment.
Transmission fluid must be at normal operating temperature. Remove plugs from right side of transmission cover. Remove test port plug from power shift control valve and install gage manifold with a 0-700 kPa (0-100 psi) gage in control valve test port.

FRONT BRAKE BAND

Start engine, put range selector in neutral and put power shift in fourth. Adjust engine speed until pressure gage reads 515 kPa (75 psi). Tighten brake band adjusting nut until engine speed drops 25 rpm. Depress clutch pedal, then loosen adjusting nut four turns.
Apply sealer to threads of plug which covers adjusting nut. Install plug and tighten until it contacts end of brake band, then loosen plug turn.

REAR BRAKE BAND

Remove jam nut, adjusting screw and plug from left side of transmission cover to gain access to rear brake band adjusting nut. Start engine, put range selector in neutral and put power shift in fourth. Increase engine speed until pressure gage reading reaches 515 kPa (75 psi). Turn brake band adjusting nut clockwise until engine speed drops 25 rpm. Depress clutch pedal, then turn adjusting nut counterclockwise four turns.
Apply sealer to threads of plug, then install plug. 

Install
- adjusting screw in plug and tighten screw until it contacts end of brake band, then loosen H turn. Tighten jam nut. Remove pressure gage and manifold. 
- test port plug into control valve. 
- plugs in transmission cover.