It is strongly recommended that the workshop manual is consulted for detail of individual procedures, clearances and setting up the gearbox.
1 Remove engine and gearbox from car.
2 Remove starter motor and clutch slave cylinder.
3 Remove the split pin from the clutch operating arm cotter and remove pushrod.
4 Undo all bolts holding the bellhousing to the engine and separate gearbox from engine - ensure that no undue strain is placed on the gearbox input shaft.
5 Drain the gearbox oil - after the oil has stopped flowing from the drain hole, replace the plug and stand the gearbox upright for a while (bellhousing downwards) to allow any oil in the rear extension to flow into the main housing. Drain the remaining oil.
6 Undo the clutch operating arm pivot bolt and withdraw the operating arm.
7 Undo the bolts securing the front cover and remove the front cover, retaining any shim(s) between it and the front bearing. Note that if the shim(s) are damaged, it indicates that the front bearing outer race has been rotating in the housing and may require attention.
8 Remove the six gearlever extension housing bolts and remove the housing - note that it is located on two dowels and will require to be rocked up and down to loosen it.
9 Undo the three detent spring retaining bolts on the top of the front end of the gearbox and remove springs inside.
10 Remove the interlock plate - slide the selector rods to and fro as necessary.
11 Remove the rear flange nut (note that it is done up to 140 ft lbs torque) - the flange itself can be held in a large stilson or vice as it will be discarded.
12 Remove the nuts and washers holding the rear extension to the gearbox and remove the extension.
13 Remove the bolts holding the side cover and remove the cover.
14 Release the locknut and bolt holding each of the three selector forks - note their position and orientation. Withdraw the selector rods from the rear of the gearbox remove the selector forks through the side cover.
15 Knock back the reverse gear lock bolt tab washer and remove the bolt.
16 Remove the reverse gear shaft through the rear of the casing and remove the gear through the side cover.
17 Remove the layshaft through the front of the gearbox casing and rest the laygear in the bottom of the gearbox.
18 Remove the main shaft assem bly from the rear of the gearbox, ensuring that the laygear is clear of the gear cluster - the easiest way to do this is for an assistant to hold the gearbox off the ground by the mainshaft and for you to tap round the rear gearbox casing with a soft face d mallet, the main bearing housing should slide out of the gearbox casing. Place a couple of pieces of wood under the bellhousing so that the input shaft does not hit the ground when the bearing housing comes free.
19 Recover the needle roller bearing from the nose of the mainshaft or from inside the input shaft assembly still in the gearbox.
20 Check the endfloat of the 1st and 2nd/3rd speed gears -
they should all be between 5 and 8 thou - if not note the clearances for later.
21 Grip the mainshaft rear distance tube in a vice - it will be discarded later - and knock back the locking tab in the slots in the front retaining nut.
22 Unscrew the front retaining nut using a "C" spanner or stilsons (pipe wrench).
23 Withdraw all the gears, synchronisers, main bearing and washers from the shaft - noting carefully the order. A press may be needed to withdraw to bearing.
24 Clean and inspect all mainshaft components for wear - especially if the clearances in 20 above were outside tolerances - replace washers or gears as necessary. It is worthwhile replacing baulk rings if synchomesh is weak on any of the gears.
25 Reassemble gears, synchronisers and washers onto the replacement mainshaft supplied in the kit - fit new lockwasher supplied and locking nut. Tighten nut and stake the lock washer into the slots in the nut. Drive replacement main bearing onto shaft after fitting the gears, fit short distance tube, lockwasher (tabs rearwards) and nut supplied. Tighten nut and stake over washer.
26 Recheck gear endfloat.
| 27 Stand the gearbox on its bellhousing and make sure the laygear will be clear of the mainshaft, |  |
| place the roller bearing in the input shaft assembly. Insert the mainshaft through the rear cover of the gearbox, making sure the laygear is clear in the bottom of the gearbox, adding the 3rd / 4th gear synchroniser after the shaft has been inserted |  |
| and aligning the cutout in the bearing housing with the peg in the gearbox. |  |
| Tap the housing gently down until it is flush. |  |
28 Replace the layshaft, ensuring that the two thrust washers are in place on the ends of the laygear.
29 Fit the new oil seal supplied into the front cover and refit the front cover using a new gasket - remembering the large shim(s).
30 Replace the clutch operating lever and its operating pushrod.
31 Replace the reverse gear shaft and reverse gear, use the slot in the rear of the shaft to align the shaft with the locking bolt - fit new lockwasher to the bolt and secure the shaft.
32 Replace the selector forks and shafts, locking the securing bolts with their nuts.
33 Replace the side cover using new gasket supplied.
34 Place new gasket on the rear of the gearbox and slide the overdrive adapter housing over the mainshaft. Secure with nuts and washers.
35 Place circlip on mainshaft followed by the OD oil pump cam which is located by the ball bearing placed in the hole in the shaft. Rotate the mainshaft so that the cam lobe is highest at the top of the gearbox.
36 Place new gasket on the rear face of the adapter housing.
37 Slide the OD unit onto the mainshaft, rotate the drive flange as necessary to align the splines. If the unit does not drop all the way onto the adapter housing - DO NOT FORCE IT - ensure that the splines inside the OD are lined up, there are two parts splined and the second one will stop the shaft entering the unit if it is misaligned. The OD oil pump roller may also bind on the cam - ease it gently downwards using a long thin screwdriver. Replace the nuts and washers and tighten.
| 38 Remove the blanking plug from your gearlever extension housing and insert the OD inhibitor switch operating shaft and spring from underneath. |  |
| Align the flat nearest the head of the shaft with the locating pin hole and drive the locating pin in from the top. |  |
| Screw the switch into the extension in place of the blanking plug. |  |
39 Replace the interlock plate and the gearlever extension housing using new gasket, ensuring that the plastic bush is on the end of the operating lever and that it fits into the selector slide. Do up the six bolts holding the extension to the gearbox.
40 Refit the drain plug and refill the gearbox with the correct grade of oil. It is easier to do this BEFORE putting the transmission back in the car, just ensure the transmission is level.
41 Refit the transmission to the engine, fit the wiring harness and refit whole assembly to car.
