The conditions are similar to those of the removal and installation of a co-axial gearbox. Apart from a hoist, auxiliary hydraulics are also necessary here for lowering the gearbox. The process itself may be more complicated, partly due to the even more unfavourable amount of space. There are vehicles, where the cowling, including radiator and headlight unit is only bolted on. In this case, one could remove the complete drive train assembly forwards from the engine compartment. However, as a rule the amount of effort necessary for this method is higher.

It must be also established whether or not one has the necessary tools. Nowadays, special screws, e.g., for the starter, are often used. The question of the economic efficiency also arises. A vital point is, what to do with the battery during the operation. Can it be disconnected, and what are the results? Must perhaps only the radio be re-coded afterwards, or are there control devices which also no longer work? Is one prepared for the results? It is hardly conceivable that one can simply strip the insulation from the very thick plus cable.

It is also important that one protects the car interior against soiling. It may be necessary, e.g., when dismantling the gear-change unit, to work on the central console. In this case, the covering of the seats and the leg room would be wise. Because nowadays, virtually no screws are tightened without a torque wrench, their numerical values should be established beforehand.

We assume, at this point, that the proper disconnection work has been done. Also that the vehicle is well secured in the working height. In the removal of an non co-axial gearbox the final drive is also removed. Therefore, our attention goes first of all to the axle drive shaft and its removability. Perhaps it is possible to loosen it from the inside of the final drive, and allow it to swing down. Otherwise it must be dismantled separately, by loosening the normally central screws of the wheel hub, and be removed. There may be, instead of the long axle drive shaft, an additional mounting on the engine with a short shaft (see above figure).

Now, all the connections with the gearbox can be loosened. Not only the electrical system, but also the gear-change unit. This poses fewer problems with a linkage system, if one can unscrew it at suitable place properly, or if it can be swung downwards from the ball joints. If Bowden-cables exist, even partly, their settings should, under no circumstances, be changed. Ideally, the gearbox is re- installed in precisely the same place as before, otherwise adjustment work is necessary

Since as a rule, the clutch housing is directly connected with the gearbox, the clutch hydraulics must be disassembled or the Bowden-cable removed. In the latter case, it can be annoying if it is self-adjusting. If the slave cylinder is mounted within the clutch housing, only draining off of the brake fluid of the clutch hydraulics helps, which means re-filling and bleeding when reassembling.

Before the mostly left-side engine mountings can be unscrewed, the engine must, in addition, be secured (normally from above). A sturdy bracket or retainer to which the engine is provisionally fastened on the flywheel side, is sufficient. Actually, now the way is free for the dismantling of the mountings of the gearbox. It must then be supported against dropping out and all the screws around the clutch housing can be loosened. During this operation caution is at hand, because the starter might fall out. Then, with a crowbar, not using too much force, the gearbox should be pulled out to the side, together with the final drive, and to be lowered. Of course, it must be ensured that no other parts, which could hinder the action, e.g., the exhaust system, are in the way.

The installation occurs in the reverse order. There can be difficulties, if at the same time, the clutch was replaced. Then the gearbox cannot as easily be pushed forward into the gearing of the clutch disc. By no means should force be used. The complete consolidation into the clutch housing is, in the motor car gearbox, basically done with muscle power. If this does not work, one must stop and check once again that the gearbox shaft has a free path into the clutch.

This description is valid, basically, also for straight-mounted, non co-axial gearboxes. Both gearbox positions can also be found in mid- or rear-mounted engines and are normally to be treated the same way. Sometimes, however, the engine or even the whole drive unit must be dismantled first.

This description is not complete for a fully automatic gearbox. During the dismantling, extreme care is to be taken against excessive oil flow if one simply loosens the screws in the clutch housing and the gearbox is pulled to the rear. It is better, in this case, to remove the torque converter from the word go. 04/07

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