425DDEFENDER 90.110 130 . -. -... ,.. . ~ . ._. , ..:.:: . ... ..1. I.
7 .MANUAL GEARBOX ..... ...... ...... .. .. .. .. ..... .*. ..... ....)I CONTENTS Page OVERHAUL DISMANTLE ..................................................................................................... 1 GEAR SELECTOR HOUSING .......................................................................... 1 EXTENSION HOUSING .................................................................................... 2 MAINSHAFT AND LAYSHAFT FIFTH GEARS ..................................................
~~ ~ - 37 MANUAL GEARBOX CONTENTS Page LOCALLY MANUFACTURED TOOLS .............................................................. 3 GEARS AND SHAFTS ..................................................................................... GEARBOX CASING .........................................................................................
LT77S - I 2 . I r MANUAL GEARBOX . DISMANTLE Bell housing - four cylinder engine 1. Remove transfer box, drain oil and clean exterior. 2. If fitted, clutch release bearing clip. 3. Remove clutch release assembly. 4. Remove one pivot post bolt, slacken the other and move post aside. 5. Remove six bolts and withdraw bell housing. GEAR SELECTOR HOUSING 1. Remove four bolts and remove main gearbox selector housing. 2. Remove transfer box housing. 3. Remove remaining bolts and remove remote housing.
I 37 DEFENDER MANUALGEARBOX roll pin. 5. Move selector shaft forward to remove quadrant. 4. Drive out quadrant n 2. Using service tool 18G 705 and 18G 705-1A withdraw the oil seal collar. & 18G 705 /U 5 ST2180M 3. Remove the fifth gear extension housing. EXTENSION HOUSING . 1. Remove snap ring retaining oil seal collar. ST2316M 2 I OVERHAUL 4. Secure the centre plate to the gearcase with two 8 x 35" bolts.
LT77S '.. MANUAL GEARBOX ~$ ~. ':. .: :r.. . I.. , 9. Remove circlip retaining mainshaft fifth gear MAINSHAFT AND LAYSHAFT FIFTH GEARS 1. 2. 3. 4. 5. ... Remove mainshaft "0" ring. Remove oil pump drive shaft. Remove "E" clips from selector fork. Remove fifth gear selector Spool. Remove selector fork bracket. synchromesh. 10. Fit special tool 18G 1400-1 and 18G 1400 as illustrated.
137 MANUALGEARBOX 11. Remove fifth gear synchromesh. ST2296M 12. Remove layshaft fifth gear using special tools 18G 705 and 18G 705-1A. 18G705-1A Main gear case. 1. Secure reverse shaft retainer, manufactured tool " A " ; to centre plate. 2. Fit studs, manufactured tool"B" to gear case. 4 1 OVERHAUL DEFENDER I 1 3. Invert gear case and locate studs in workstand holes. 4. Remove selector shaft spool retainer. -.
MANUAL GEARBOX LT77S REVERSE SHAFT, LAYSHAFT AND MAINSHAFT 5. Remove front cover and gasket. 6. Retrieve selective washers. 1. Remove retainer (tool "A") and reverse shaft. 2. Remove thrust washer, reverse gear and spacer. 3. Remove reverse lever pin with "E" clip attached. 4. Remove lever and slipper pad. 7. Remove bolts and lift-off gear case. 8. Secure centre plate with nut and bolt.
I 37 MANUALGEARBOX DEFENDER 5. Remove input shaft and fourth gear baulk ring. 6. Remove layshaft by tilting, as illustrated and lifting mainshaft. 5 ST ST3245 M 7. Unscrew plug and remove spring and outboard detent ball. 8. Align fifth gear selector pin with centre plate slot. 9. Remove mainshaft, gears, selectors and forks. 10. Remove selector fork assembly from gears. I U 11. Collect inboard detent ball and spring from centre plate.
Ll77S MANUAL GEARBOX ..c.:"..:: , , , ,..... ..::.:, ... ... , , II 1 .. 12. Using extractor tool 18G 705 and collets 18G 705-7, withdraw layshaft bearings. \ ST3246M, - . . \ DISMANTLE MAINSHAFT 1. Remove circlip retaining first gear assembly. 4. With MS 47 press first gear assembly from mainshaft. r ST 2. Remove taper bearing, bush, needle bearing, first gear spacer, cone, inner and outer baulk rings. 3. Remove circlip to release first and second gear synchromesh assembly.
137 MANUALGEARBOX 5. Remove first and second synchromesh baulk rings. 6. Using MS 47 and support bars under second gear, press off pilot bearing, third, fourth synchromesh second and third gear assembly. DEFENDER GEARBOX CASINGS AND OIL PUMP Degrease and clean all components and discard gaskets and seals. Gearbox casing 1. Remove mainshaft and layshaft bearing tracks. 2. Remove plastic scoop from inside the casing. 64 ST3326M i 7.
LT77S Centre plate 1. Remove bearing tracks. 2. Inspect for damage and selector rail bore for wear. 3. Temporally fit reverse shaft gear and lever and check clearance between slipper and lever does not exceed 0,20 mm (0.008 in). MANUAL GEARBOX 3. Check oil pick up pipe for obstruction but do not remove. 4. Remove drain plug assembly. Clean and renew filter and washers if necessary. 5. Renew oil seal. 6. Renew Ferrobestos bush. A WARNING: This bush contains abestos. Do not attempt to clean it.
I 37 MANUALGEARBOX DEFENDER 9. Fit oil seal to housing, lip side leading, using 18G 1422. Apply SAE 40 oil to lip. ST2186M 3. Drive-out roll pin to remove bias spring. 4. Remove gear lever extension from lower gear lever. 5. Remove bolt and special washer to remove lower gear lever. A WARNING: Hold the nylon spring loaded pad while removing the lever t o prevent it causing personal injury. 6. Remove gear selector housing from remote housing. 10. Assemble gears to oil pump and fit cover.
LT77S , "' MANUAL GEARBOX 7. Clean and examine all components and renew where necessary. 8. Assemble above parts In reverse order using multi-purpose grease on gear lever. 10. Remove circlip to release rollers and pin from quadrant. NOTE: Ensure spring loaded pad is properly located and that the lever is fitted to the housing with the pad on the opposite side to the bias spring. Leave bias spring adjusting screws slack until assembly of gearbox. Remote gear lever housing. 1.
1 DEFENDER 37 - MANUAL GEARBOX ( -, _. GEAR SELECTOR HOUSING I 1.: tI 0,: i/' 1. Gear selector housing 2. Gasket 3. Roll pin 14. Reverse gear plunger 15. Gear lever Seating 16. Trunnion 19. '0' ring 20. Selector shaft 21. Quadrant 22. Roll pin 23.
LT77S Reverse gear plunger assembly. 1. Remove plug spring and ball. 2. Remove circlip to release plunger and spring. 3. Clean and examine components. 4. Assemble plunger and spring with multi-purpose grease and secure with circlip. 5. Lubricate and fit detent ball and spring with light oil. Apply Loctite 290 to plug threads and fit. 6. Check that plunger returns when depressed. ST2201 M Transfer gear housing. 1. Remove the four screws and remove gaiter assembly. 2.
137 MANUALGEARBOX DEFENDER -12 15 I 17 ST 2185 M 1. Gaiter retaining screw - 4 off, 2. Gaiter. 3. Gaiter support plate. 4. Gate plate. 5. Gasket. 6. Split pin. 7. Clivis pin. 8. Circlip retaining Nylon seat. 9. Gear lever ball. 10. Nylon seat. 11. 12. 13. 14. 15. 16. 17. 18. 19. Cross shaft. Gear lever. Gear change housing. Non-mettalic bushes. Counter sunk screws. End cover. Detent spring and plate. Selector fork. "0" rings.
LT77S MANUAL GEARBOX SYNCHROMESH ASSEMBLIES Third-fourth and fifth gear synchromesh. NOTE: the above assemblies are the same except that fifth gear synchromesh has a retainer plate. 1. Mark relationship of inner and outer members. 2. Remove wire clip from both sides of assembly. ST2803M 7. Examine the dog teeth on all gears for wear and damage. a NOTE: example"A shows a tooth in good condition. Example"6" shows the rounded corners of a worn tooth. 3. Remove slippers and separate the two members. 4.
137 MANUALGEARBOX DEFENDER First-second synchromesh 12. Fit the slippers and secure with a spring each side of the synchromesh. 8. Repeat instructions 1 to 6 for third-fourth synchromesh. 9. Examine step in each of outer splines. 10. Check that the step on both sides of the internal splines are sharp not rounded. NOTE: The hooked end of each spring must locate in the same slipper with the free ends running in opposite directions and resting against the remaining slippers.
LT77S CHECKING BAULK RING CLEARANCES MANUAL GEARBOX Third gear Check clearance of all baulk rings and gears by pressing the baulk ring against the gear and measuring the gap. The minimum clearance should be 0,38mm (0.015in).
I 37 MANUALGEARBOX INPUT SHAFT DEFENDER 6. Using Press M S 47,Collets 18G 478 and adaptor 18G 47 BAX fit a new taper bearing. 1. Examine the gear and dog teeth for wear and damage. 2. Polish oil seal track if necessary. 3. Using 18G 284 AAH and 18G 284 remove pilot bearing track. 18G284AAH \ 18G284 ....-.. -- \ ~ .?. :c , t.:., _r ST3278M 4. Using 18G 47BA and MS 47 remove taper bearing. 0 NOTE: ensure that the bearing is supported by the lip inside 18G 47 BA. MAINSHAFT 1.
LT77S MAINSHAFT GEAR END FLOAT CHECKS 1. Hold mainshaft in vice front end downwards. 2. Fit front circlip for first-second synchromesh. 3 . Fit second gear cone. 4. Fit spacer. 5. Fit snap ring. MANUAL GEARBOX Third gear end-float. 1. Fit needle roller to third gear. 2. fit third gear bush to third gear. 3. Place gear on flat surface, bush flange downwards, and with a straight edge across gear check clearance between straight edge and gear. Not to exceed 0,20 (0.008in).
1 37 MANUALGEARBOX 3. Fit first-second synchromesh hub, fork groove uppermost. 4. Fit circlip. - ST3231 M First-second synchromesh assembly DEFENDER 8. 9. 10. 11. Fit first gear bush. Fit dummy bearing. Fit circlip. Check clearance between dummy bearing and bush. Not to exceed 0,75mm (0.003in). 12. Remove circlip, dummy bearing and bush.
LT77S MANUAL GEARBOX 3. Place straight edge across gear and check clearance between gear and straight edge.Not to exceed 0,20mm (0.008in). 3 1 ' 37 / \ ST3255M ASSEMBLING MAINSHAFT 4. Fit the taper bearing to mainshaft using MS 47, collets 18G 47 BA and adaptor 18G 47 BAX. 1. With the first-second synchromesh hub and spacer in position, assemble the rear end of the shaft. 2. Fit the roller bearing and bush to first gear. 3. Fit first gear to mainshaft. MS47- (.
37 MANUAL GEARBOX DEFENDER 5’2 CAUTION: Ensure that the slots in the baulk ring align with the synchromesh slippers while pressing on the bearing. A 5. Invert mainshaft and press assembly back against circlip. 7. Posltlon mainshaft in vice, rear end downwards and fit second gear needle roller, and second gear. 8. Fit third gear bush. 9. Fit third gear needle rollers. 10. Fit third gear. 11. Fit third gear baulk ring.
LT77S MANUAL GEARBOX 12. Fit third-fourth gear synchromesh hub. 13. Using MS 47 with supports under first gear, press the spigot bearing on to shaft. LAYSHAFT 1. Examine the layshaft for wear and damage. 2. Press bearings on to layshaft using MS 47 and supporting bars. i -12 MS.47 "U/ / \ ST3266M REVERSE GEAR AND SHAFT 1. Remove one circlip from the idler gear and remove bearings.
1 37 MANUALGEARBOX DEFENDER p v NOTE: One bearing cage is twisted in manufacture. The twist causes the gear to tilt on the shaft forcing the gear into engagement. Renew bearings if worn or if the gear jumps out of engagement. A SELECTORS . ; 1. Examine selector rail and pins for wear and damage. 2. Examine first-second selector fork for wear cracks and damage. NOTE: The the selector rail and fork is only supplied as a complete assembly. 3.
MANUAL GEARBOX LT77S .. A Assembling selectors. 7. Rest first-second fork and shaft assembly on bench and locate pin in jaw of fork. 8. Fit interlock spool and third-fourth fork and engage spool in jaw of fork. ASSEMBLING GEARBOX SHAFTS TO CENTRE PLATE Fitting gears to centre plate 1. Secure centre plate to workstand, fit bearing tracks and inboard detent ball and spring. 8 7 ST2-M 9.
137 MANUALGEARBOX 4. Fit layshaft While lifting mainshaft to clear layshaft rear bearing. 5. Turn selector shaft and interlock spool to allow reverse lever to engage spool flange. 6. Fit reverse lever to pivot post and secure with pin and circlip. 7. Fit slipper pad to lever. 8. Fit reverse gear shaft, spacer and gear. 9. Fit slipper to reverse gear and ensure roll pin in shaft engages in slot in centre plate. I I DEFENDER 10. Secure reverse shaft with manufactured tool "A". 11.
MANUAL GEARBOX LT77S 2 I >- : FITTING GEARBOX CASING 1. Turn selector shaft and spool to neutral position. 2. Fit out-board detent ball and sprlng and secure with plug. ST2515M CAUTION:,Do not use force to fit retainer. Provided the spool has not been disturbed the retainer will slide into position. If not, remove the gear case and reposition spool or shaft. A 2 ST2494M 3. Fit guide studs to casing and check oil scoop correctly fitted. 4. Without using force, fit gearcase. IS 7.
137 MANUALGEARBOX DEFENDER 6% FITTING FIFTH GEAR 4. Fit a new stake nut but do not tighten. 5. Fit fifth gear assembly to mainshaft. CAUTION: Since the fifth gear is a tight fit on the layshaft, the force, when pressing the gear, must not be transfered to the layshaft front bearing. Tool"D"and packing disc should be made to the dimensions given to absorb the force. The plate also retains the input shaft bearing outer track. A 1. Secure the plate with two 8x25" bolts.
MANUAL GEARBOX LT77S ;:::-: ... .. .. .. ,::.q ......,' !:. ... ~.I, I 6. Press fifth gear synchromesh assembly to mainshaft using 18G 1431. A CAUTION: Before pressing the assembly fully home, ensure that the slipper pads locate in the baulk ring slots. Part number Thickness FRC 5284 FRC 5286 FRC 5288 FRC 5290 FRC 5292 FRC 5294 FRC 5296 FRC 5298 FRC 5300 FRC 5302 5,lO 5,16 5,22 5,58 5,34 5,40 5,46 5,52 558 5.64 7. Fit the thinnest washer and secure with circlip. 8.
1-37 MANUAL GEARBOX 10. Secure tool " A" to gear and gear case and using a suitable torque wrench tighten the nut to the correct torque. DEFENDER FIFTH GEAR SELECTOR FORK ASSEMBLY 1. Fit fifth gear selector fork bracket. 2. Fit the fifth gear spool long end towards centre plate. 11. Using a round nose punch, form the collar into the layshaft slots. 3. Fit slippers to selector fork. 4. Fit fork to synchromesh and secure with pins and "E" clips.
MANUAL GEARBOX LT77S ..-. .. , ~:,.' .f. . , .... ...,.. .... EXTENSION CASE 1. Release centre plate from workstand and fit gasket on joint face. 2. Fit extension case while aligning oil pick-up pipe. Remove guide studs and secure to main case. NOTE: Do not use force, if necessary remove case and re-align oil pump drive if case does not fit first time. A CAUTION: To protect "0" ring while fitting, cover mainshaft splines with smooth tape. 3. Fit "0" ring to mainshaft groove. 4 .
137 MANUALGEARBOX DEFENDER r j I, INPUT-MAINSHAFT BEARING ADJUSTMENT 1. Turn gearbox over with input shaft uppermost. Mainshaft selective washers Part number Thickness(") FRC 4327 FRC 4329 FRC 4331 FRC 4333 FRC 4335 FRC 4337 FRC 4339 FRC 4341 FRC 4343 FRC 4345 FRC 4347 FRC 4349 FRC 4351 FRC 4353 FRC 4355 FRC 4357 FRC 4359 FRC 4361 FRC 4363 FRC 4365 FRC 4367 FRC 4369 131 137 !,63 1,69 1,75 1,81 1,87 1,93 1,99 2,05 2,ll 2,17 2,23 2,29 2.
LT77S .'A .. MANUAL GEARBOX a NOTE: This will ensure zero layshaft bearing end float and not more than 0,025" (0.001 in) pre-load once the cover and gasket are fitted and bolts correctly torqued. 3. Remove cover and selected washer and fit new oil seal, lip towards gearcase. 4. Fit mainshaft and layshaft selected washers and gasket. GEAR LEVER AND REMOTE HOUSING ASSEMBLY 1. Fit quadrant to selector shaft with new roll pin.
137 DEFENDER MANUALGEARBOX NOTE: If necessary, final adjustment can be made in vehicle. To increase pull-over load turn screw clockwise or anti-clockwise to reduce load. Fifth gear stop screw adjustment. 1. Adjust screw to protrude from housing the distance across corners of locknut. NOTE: This i s only an approximate setting which will limit travel of selector yoke but will allow fifth gear t o be selected.
LT77S I '8: i , MANUAL GEARBOX .. I BELL HOUSING - FOUR CYLINDER ENGINE 1. Fit bellhousing locating over hollow dowels and BELL HOUSING - V8 ENGINE 1. Fit bell housing locating on hollow dowels. secure with bolts. NOTE: Fit the 12 x 45" bolts through dowels and 12 x 30" bolts in remaining positions. NOTE: Fit the 12 x 45 mm bolts through dowels and 12 x 30 mm bolts in remaining positions. 2. Secure pivot post. 3. Apply molybdenum disulphide grease to pivot post, lever pads and pins. 4.
MANUAL GEARBOX LT77S . . .. DATA Reverse lever and slipper pad clearance .......................... 0,725 mm Reverse gear plunger operating load ................................ 45 to 55 kg Synchromesh assemblies push through load ................_...8,2 to 10 kgf Clearance between baulk rings and gears ........................ 0,38 mm Fifth gear end float ............................................................ 0,020 mm Third gear end float ..........................................................
MANUAL GEARBOX LT77S SERVICE TOOLS NOTE: Where the use of special tools is specified, only these tools should be used to avoid the possibility of personal injury and or damage to components. 18G 1400 Remover synchromesh hub and gear cluster -. __ 18G.7400- 1 18G 705 Puller, bearing remover 8G 1400-1 8G 705-1A Adaptor mainshaft fifth gear Adaptor for mainshaft oil seal track and layshaft fifth gear ia~.705- 0 8G 705-7 MS47 1s 47 Hand press 186.
37 DEFENDER MANUAL GEARBOX 18G.1431 18G.
LT77S MANUAL GEARBOX . .. -" \ LOCALLY MANUFACTURED TOOLS In addition to the special service tools, the following tools can be locally made to assist the dismantling and assembly of the gearbox. The following overhaul procedure is based upon the assumption that these tools are available. Tool 'C'. Mild steel dummy centre bearing for the selection of first gear bush. C A 53.0" -+ 0.10 Tool 'A'. Dual purpose tool. Reverse shaft retainer to prevent the shaft falling out when the gearbox in inverted.
137 MANUALGEARBOX DEFENDER Tool 'E'. Workstand for securely locating the gearbox x 30" during overhaul. Manufacture from 30" angle iron. The single hole marked 'A' should be drilled through the material with a 10" drill. 1 52mm The four counter sunk blind holes marked 'B' should also be made with a lOmm drill, but must not be drilled through the material.
LT77S MANUAL GEARBOX . ...... .,. ,: ..... I. .I . ..... :: ,. I:. , *,;A. ! GEARS AND SHAFTS 1. Third - fourth selector fork. 2. Interlock spool. First - second fork and selector rail assembly. First - second synchromesh. First gear synchromesh outer baulk ring. First gear synchromesh inner baulk ring. Cone. Thrust washer. First gear. 10. Needle roller bearings. 11. First gear selective bush. 12. Centre taper roller bearing. 13. Circlip. 14. Thrust washer. 15. Fifth gear. 16.
I I 37 MANUALGEARBOX Si3281 M SERVICE TOOLS DEFENDER
MANUAL GEARBOX LT77S r . . c , ,U, GEARBOX CASING 1. Front cover. 2. Front cover oil seal. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. Front cover gasket. Oil drain plug and washer. Oil level plug. Gearbox main casing. Spool retainer. Gasket. Inboard detent ball and spring. Reverse lever and slipper. Locating dowels - centre plate to maincase. Reverse lever pivot post. Centre plate. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. Selector plug, detent ball and spring. Gasket. Fifth gear selector bracket.