Most of these are owner experience, with a few factory (TIS) procedures for the F23 gearbox. Start with the first section if you are replacing a clutch.
Clutch and flywheel
- Clutch choice
Which clutch to fit: the standard Vauxhall clutch, the C20LET clutch, the Courtenay Sport fast road and competition clutches, and paddle clutches, with the torque each is said to handle, owners’ experiences (including failures), and when a lightened flywheel makes sense. - Clutch replacement: dropping the gearbox
An overview of changing the clutch and flywheel without removing the engine or the rear clam: the methods owners use to drop the gearbox, an ordered job list, the extra things people forgot, and why the slave cylinder should always be replaced. For the full Turbo walkthrough with part numbers and torques, see the F23 guide. - F23 gearbox removal and clutch replacement
Dropping the Getrag F23 gearbox out of the back of a VX220 Turbo to replace the clutch, slave cylinder and flywheel bolts. The engine and gearbox are lowered on jacks, so it is a long job (about 12 hours the first time) rather than a difficult one. - Flywheel removal and refitting
The factory steps for taking off and refitting the flywheel, and for checking it, from the Vauxhall TIS. - Lightened flywheel: daily driving, engine braking and what owners found
Whether a lightened flywheel makes a daily car harder to pull away in traffic, why owners disagreed about engine braking, the weights and price mentioned, one owner's timed before-and-after, and whether it is worth fitting while the gearbox is out. Forum opinion from 2010 to 2015.
Clutch hydraulics
- Clutch master cylinder, slave cylinder and bleeding
What to do when the clutch pedal goes to the floor or feels floppy: leaking master cylinder (and the parts owners have used instead of the unobtainable Vauxhall one), the slave cylinder that sits inside the bell housing, and how to bleed the clutch.
Gearbox oil, seals and removal
- Gearbox oil replacement
How often to change it (no official interval, but change it anyway), and how to drain and refill the gearbox oil on an NA: warm the box, loosen the fill plug first, drain from below the left driveshaft, and refill through the fill plug. How much oil goes in is disputed, so use the level plug to check if you can reach it. All the original photos are lost. - Gearbox oil leak: breather, overfill and seals
A 2013 thread about a car that smoked and sprayed oil down the nearside after a gearbox swap, and what owners said about the gearbox breather, overfilling, where the filler, level and drain plugs are, the shaft seals and the oil grade. The cause was never confirmed in the thread. - Driveshaft removal and gearbox driveshaft seals
How owners take a driveshaft out of the gearbox, how much oil you lose, and how to replace the driveshaft oil seal without wrecking it. The seal is the hard part: it is a very tight fit and needs a tool that presses on the outer rim. - Gearbox removal with the engine out
The factory steps for taking the gearbox off an engine that is already out of the car, and for separating and rejoining the NA gearbox and engine, from the Vauxhall TIS.
Gearbox overhaul and differential
- F23 gearbox overhaul: shafts and bearings (NA)
The factory steps for the shaft and bearing work on the F23 gearbox: the bearings in the clutch and gearbox housings, the main shaft, the intermediate shaft and its cover, from the Vauxhall TIS (NA pages). - Limited-slip differential: fitting (F23 gearbox)
Swapping the standard differential in the F23 gearbox for a limited-slip one (an ATB such as a Quaife). With the gearbox out, you split the case, move the crown ring across to the new diff, fit the bearings and shims, and put it back together. A specialist job: it needs careful measuring of the shims, and a clearance check before you close the case.
Gear change
- Gear cables: faults, choosing and adjusting
Stiff or sticking gear change: how to tell whether it is the cables, the gearbox or the selector, why the original cables melt, what the aftermarket Cablecraft cables are like (including the self-centring and seal problems), prices from 2003 to 2015, NA and Turbo fitment, and how to adjust the linkage. - Gear cable replacement
Changing the two gearbox cables, from one owner's 2012 photo guide with later corrections: undertray, gearbox ends, seat and centre console out, the remote assembly lifted and the cables pulled through. Includes which cable is which, the rivet debate and the rod end that was too long. - Gear shift linkage adjustment and shift mechanism
The factory steps for adjusting the gear shift linkage, and for removing the shift cables, gearshift lever, shift mechanism, shift forks and reversing lamp switch, from the Vauxhall TIS (NA pages).