Assembly and Adjustment
MAINSHAFT REASSEMBLY.1. Clamp mainshaft in protected vice jaws, output end upwards.
2. Fit 2nd gear needle roller bearing, 2nd gear and synchromesh baulk rings onto mainshaft. (Rotate each baulk ring to ensure they locate onto each other).
3. Assemble the 1st and 2nd synchromesh selector hub onto mainshaft spline, (note 2nd speed side marking). Ensure that baulk ring has located correctly inside hub. (Rotate the ring slightly as the hub is lowered).
4. Fit 1st gear synchromesh baulk rings. needle roller bearing. 1st gear and bush onto mainshaft ensuring baulk rings locate correctly inside selector hub.
5. Using LRT-99-002, bearing guide LRT-37-019, collets LRT-37-001 and adaptor LRT-37-002 press onto mainshaft taper roller bearing taking care not to disturb the lay of the synchromesh baulk rings and gears.
6. Check the end float of the 1st and 2nd gear assembly using a feeler gauge between the 1st gear and mainshaft bearing. Maximum clearance should be 0.05-0.15 mm (0.002-0.006 in).
7. Invert mainshaft in vice and fit 3rd gear needle roller bearing third gear and synchromesh baulk rings.
8. Assemble 3rd/4th gear synchromesh selector hub (note 3rd speed side markings) onto mainshaft splines taking care to locate the baulk rings into recesses in the selector hub.
9. Fit spacer
10. Using LRT-99-002 press on new pilot bearing.
Check end float of 3rd gear assembly as in step 6.
REVERSE IDLE GEAR
1. Examine components for wear and damage.
2. Assemble reverse idle gear needle roller bearing, idle gear, spacer and shaft and using suitable tool, press into centre plate. Maximum clearance should be 0.05-0.04 mm (0.002 in - 0.0016 in)
SELECTORS.
1. Examine selector rail and pins for wear and damage.
2. Examine selector forks for wear and damage.
Note:
The selector rail and fork is only supplied as a complete assembly.
3. Examine interlock spools for wear and damage.
4. Remove snap ring and examine selector yoke assembly.
Assembling selectors.
1. Rest 1st/2nd fork and shaft assembly on bench and locate pin in jaw of fork.
2. Fit interlock spool and 3rd/4th fork and engage spool in jaw of fork.
3. Slide spool and fork towards 1st/2nd selector until slot in spool locates over pin keeping the spool engaged in 3rd/4th fork jaw.
MAINSHAFT AND LAYSHAFT END FLOAT.
Note:
The end float setting for both the mainshaft and the layshaft has to be determined before the gear box can be reassembled. This is achieved by clamping the mainshaft and layshaft separately between the centre plate and main casing and measuring the movement on each shaft with a Dial test indicator.
The end float setting for the mainshaft is 0.0125-0.06 mm (0.0005-0.0025 in).
The setting for the layshaft is 0.00 mm +/- 0.025 mm (0.00 in +/- 001 in)
Note:
The layshaft settings allow for 0.025mm end float to 0.025mm preload.
Shims to make up the required clearances are placed under the bearing tracks of the centre plate.
SHIMMING.
1. Fit bearing tracks to main casing front cover.
2. Fit front cover to casing without oil seal.
3. Clamp casing in vice with front cover downwards.
4. Fit input shaft. Do not fit 4th gear baulk ring.
5. Fit mainshaft assembly to input shaft
6. Fit mainshaft bearing shim and track to centre plate.
7. Fit centre plate and bolt down using 8 "slave" bolts.
8. Fit large bail bearing to rear of mainshaft.
9. Mount dial test indicator.
10. Rotate mainshaft to settle bearings.
11. Lift mainshaft and note reading.
12. Dismantle and substitute shims if reading incorrect.
13. Repeat procedure.
14. Remove mainshaft assembly and repeat procedure for layshaft.
15. Dismantle assembly in preparation for assembly on stand.
ASSEMBLING MAINSHAFT AND LAYSHAFT TO CENTRE PLATE.
1. Secure centre plate to workstand.
2. Fit selected shims and bearing tracks.
3. Fit inboard detent ball and spring, use a dummy bar to temporarily hold the bail in place.
4. Check both synchromesh units are in neutral and fit selector shaft to mainshaft.
5. Fit mainshaft and selectors as complete unit to centre aligning pin with slot in plate.
6. Fit 4th gear synchromesh baulk ring.
7. Fit layshaft whilst lifting mainshaft to clear layshaft rear bearing.
8. Lubricate pilot bearing and fit input shaft.
9. Fit oil seal to front cover. Apply Hylogrip 2000 as shown.
10. Fit bearing tracks and clips to main case and fit front cover. Seal fixings with Hylogrip 2000.
11. Apply Hylogrip 2000 and fit main casing to centre plate.
12. Bolt casing and centre plate together using 2 or 3 slave bolts.
13. Fit new "O" ring and fit spool retainer.
14. Remove casing from stand and clamp in vice.
REVERSE AND 5TH GEAR REASSEMBLY.
1. Fit mainshaft reverse gear selectable washer, bush and needle bearing.
2. Fit mainshaft reverse gear and synchromesh baulk ring.
3. Fit layshaft reverse gear.
4. Assemble selector spool. selector fork and reverse/5th gear synchromesh hub. Fit as one assembly to mainshaft and selector shaft. (Ensure synchromesh baulk ring locates inside hub)
5. Fit new circlip should be snug
Note: The fit of the circlip is controlled by the selectable washer behind the reverse gear.
6. Fit 5th gear split needle bearing.
7. Fit 5th gear and 5th gear synchromesh baulk ring to mainshaft.
8. Fit layshaft 5th gear.
9. Fit new mainshaft thrust collar roll pin. Locate 5th gear segments and retaining ring.
Note:
The following procedures (10) & (11) apply to this bulletin only. A new procedure for tightening 5th gear layshaft nut will follow in a later bulletin.
10. Select 5th and 1st gear to lack the gear box.
11. Using LRT-51-003 to hold layshaft 5th gear. tighten the Layshaft 5th gear nut to 203Nm.
12. Select neutral.
13. Stake layshaft 5th gear nut.
14. Using tool LRT-37-015 and LRT-37-21 press mainshaft rear support: bearing track to collar on mainshaft.
15. Apply small amount of heat and fit layshaft rear support bearing.
EXTENSION HOUSING
1. Remove all "slave" bolts from centre plate and casing.
2. Refit oil filter.
3. Apply Hylogrip 2000 to mating surfaces and fit extension housing ensuring oil pipe locates in filter and roller bearings are not dislodged.
4. Bolt extension housing to centre plate and main casing.
5. Apply Hylogrip 2000 and fit extension case spool retainer.
6. Using LRT-37-015 and LRT-37-21 press on mainshaft oil seal collar.
7. Fit selector rod yoke and secure with new grubscrew. Tighten to 22-28 Nm.
8. Apply Hylogrip 2000 to mating surfaces and fit gear change housing. Ensure gear lever pin passes through the centre of the yoke.
Note:
If the oilcooler or bypass blocks have been removed during overhaul, replace all "0" rings on assembly.
BIAS ADJUSTMENT. (RANGE ROVER/DISCOVERY).
1. Slacken bias adjustment plate bolts. Select fourth gear and move lever fully to the right.
2. Tighten adjustment plate bolts.
3. Check adjustment is correct by selecting third and fourth gears.
4. Fit sealing rubber to gear change housing. apply Hylogrip 2000 to screws and fit cover.
FIFTH GEAR STOP SCREW ADJUSTMENT. (DEFENDER ONLY)
1. Select reverse gear. While applying light pressure to gear lever towards right, turn screw clockwise until it contacts yoke.
2. Turn screw anti-clockwise until 25mm free play is felt at knob, ensure 5th gear can be engaged.
3. Tighten locknut.
4. Check all other gears are selectable.
BIAS SPRING ADJUSTMENT. (DEFENDER ONLY)
Note:
The purpose of this adjustment is to set both bolts so that the bias spring legs apply equal pressure on both ends of the gear lever cross pin when third or fourth gear is engaged.
This will ensure that when the lever is in neutral, the gear change mechanism is automatically aligned for third or fourth gear.
1. Select third or fourth gear.
2. Adjust the two adjusting screws until both legs of the spring are approximately 0.5mm clear of the cross pin in the gear lever.
3. Apply a slight load to the gear lever in a left hand direction and adjust the right hand adjusting screw downward until the right hand spring leg just makes contact with the cross pin.
4. Repeat the same procedure for the left hand adjusting screw.
5. Lower both adjusting screws equal amounts until the radial play is just eliminated.
6. Tighten locknuts.
7. Return gear lever to neutral position and rock across the gate several times. The gear lever should return to the third and fourth gate.
Refit Bell housing.
Refit clutch lever and thrust bearing.
Refit to Transfer box.
Refit to vehicle.
Refill with appropriate gear oil.