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by Frank Owen, Art Veh
To answer the question, here is the sequence as I recall, but first, it is not possible to remove the clutch without either removing the engine or the gear box.
The gear box has no more than about half an inch movement when the mounting bolts are removed and the clutch input shaft is about 4 to 5 inches inside the engine.
Removal of the engine should not be taken on unless it has to be replaced and that sequence may overtax my memory.
Take your time, think about each step and don't stand under anything heavy. I remember one of my LAD OCs from Armoured Regiment days, came to the rear of the tank I was doing a clutch change on to ask me how I was going, I looked up and the gear box was suspended directly over his head, he saw the look on my face, looked up and moved like a rocket.
| Step 1. | Raise the transmission decks and lay them on the engine decking. |
| Step 2. | Raise the radiators and lean them on the side walls of the compartment |
| Step 3. | Remove the rear footplate, the centre support rail and the 2 foot plate support brackets. Make sure that all of the bolts/nuts/washers are kept in a safe place |
| Step 4. | Remove the thin baffle plate from between the main engine fans |
| Step 5. | Remove the tiewire from the quill shaft retainers (half moons), remove the half moons and withdraw the quill shafts from the gear box. They will slide into the final drive so that just the inner splines are visible |
| Step 6. | There are 4 transmission mounting bolts, 2 holding the front gear box mounting and 2 to the rear of the box, the bolts on the front mounting are wired and will unscrew to allow the top of the mounting to be removed. The 2 rear mounting bolts are placed in position from the top and are secured by nuts which have to be held during removal. They are normally bloody tight |
| Step 7. | The clutch drive flange is secured to the gear box by about 8 or 10 bolts, I can't remember if they have nuts or if they are wired, could be both. When there are only a couple of bolts to remove it will be necessary to support the clutch with a large socket or such to prevent the clutch dropping. |
| Step 8. | The gear box should now be ready for removal using the eye bolts on top. It may be necessary to hold the radiators in the vertical position when lifting the gear box out. When removed (I think it weighs half a ton), make sure that the shims under the rear mountings are kept separate (L & R). The front bottom mounting is then removed, once again there are shims that must be replaced where they came from when reassembling. |
| Step 9. | The rear main oil seal housing, located at the front of the engine (the engine is fitted to a Centurion with the front of the engine to the rear of the vehicle) is secured by about 8 nuts (I think) these must be removed and the seal housing withdrawn so that it sits loose on the clutch drive shaft |
| Step 10. | The clutch should now be ready for removal. A suitable sling can be made by manufacturing 2 hooks from 5/16 steel rod with an eye fashioned at the other end. The hooks are placed into the vent holes around the clutch housing and the eyes attached to suitably strong slings (chains preferably). You will have to roughly work out the balance point. |
| Step 11. | Take the weight of the clutch and slowly ease it out of the engine making sure that no damage is done to the studs in the engine. |
| Step 12. | Carefully lift the clutch out of the transmission compartment after ensuring that it is balanced or you might lose it. |
| Step 13. | Before replacing the clutch a new seal should be fitted, using great care, because by now you will have discovered what a bastard of a job it is. |
The replacement sequence is merely the reverse of the removal but there are a couple of things that may ease the replacement sequence, particularly of the gear box.