Simplified Gearbox Removal and Refitting

R H Johnston

The method of gearbox removal and refitting given in the Workshop Manual is not easily performed by one person, and even with two people and a pit, the method suggested is likely to result in damage to the bearings of the input driveshaft as a result of the full weight of the gearbox being accidentally allowed to hang on the input shaft. The following method is very much easier and the risk of damage is much reduced, both to the gearbox and the operator!

The basic procedure is in the Workshop Manual and will not repeated here. The exception is that the rear of the car is lifted up instead of the front, so that the rear wheels are several inches off the floor. Use ramps or tall axle stands to achieve this. Then when the rear of the gearbox is lowered using a jack, it is lowered until it is horizontal, and its weight is then taken by a low platform on wheels (I made one from the wheels from a discarded spindrier, with a flat plate riveted on top to give a flat surface). When the attachment screws between the clutch housing and the engine are removed, the gearbox is then rolled backwards away from the flywheel and clutch without any weight being taken by the input shaft. To ensure that there is no weight taken by the input shaft, the exact height at the front of the car can be adjusted using a jack.

Refitting the gearbox is simply the reverse process, but there is no longer a need for hurculean strength to lift the gearbox into location and hold it there while doing up the screws. Instead the gearbox and flywheel centre are accurately aligned by raising the front of the car slightly with a jack as required to get the correct level, and then the platform is moved along until the input shaft engages fully in the flywheel and the crankshaft bush.

Whilst great care is taken to ensure that the technical information and advice offered is of the highest standard, neither the author, nor The Austin A30/A35 Owners Club, or the Officers of the Austin A30/A35 Club accept any liability at law for any death, injury or loss whatsoever arising from the use of advice contained in this article.