Gearbox removal

[Mark Wilson]

While accessing my clutch yesterday I struggled to drop the gearbox below the steering rack. I haven't done this operation before, but from online videos I think the engine usually drops slightly lower. I'd removed the steady bar and I don't have a heater valve in the usual position, but movement was limited by the backplate starter motor protrusion hitting the chassis leg. Is the Midget 1275 back plate slightly deeper than the standard engine? It only needs to come down a few mm more, but I had to persuade it by levering with a large screwdriver from above, which may not be an option when refitting.

[philthehill]

The depth of the 1275cc Midget backplate is the same as the 1098cc Minor back plate which is the same as the 948cc Minor back plate.

[simmitc]

Without seeing it, it's difficult to know by how much your engine has lowered, but you might need to loosen the front engine mounts and also, of course, disconnect the exhaust and the top radiator hose, all can make a difference. It is also usual to need to first move the gearbox backwards by just enough to disengage the dowels, and then rotate it so that the bell housing clears the steering rack. Be VERY careful at this stage, if you pull the box back too far, then it can snap the top of the bell housing where it hits the rack. It is also important that the box does not hang on the input shaft, the box must be properly supported.

[Mark Wilson]

Without seeing it, it's difficult to know by how much your engine has lowered, but you might need to loosen the front engine mounts and also, of course, disconnect the exhaust and the top radiator hose, all can make a difference. It is also usual to need to first move the gearbox backwards by just enough to disengage the dowels, and then rotate it so that the bell housing clears the steering rack. Be VERY careful at this stage, if you pull the box back too far, then it can snap the top of the bell housing where it hits the rack. It is also important that the box does not hang on the input shaft, the box must be properly supported.

Very helpful advice, thanks. I did struggle to refit the gearbox under the steering rack until I removed one engine mount. Others have probably done something similar, but anyone working solo from a garage floor might find my method of temporarily supporting the gearbox useful - two ratchet straps between the torsion bars. I didn't remove the gearbox cover as I didn't want to disturb my beautiful new interior!