Ford Type 9 5-Speed Sump Plug

The Ford Type 9 5-speed gearbox is a popular conversion for the MGA and many other classics. The gearbox when fitted in the Sierra by Ford was sealed for life. Consequently it does not have a sump plug to aid an oil change (SAE 75-90 semi synthetic oil).  Perhaps Ford did not foresee the gearbox outliving the Sierra's life.  Gearboxes now being supplied by many conversion companies come with a sump plug conversion.

For those of us who have been running the gearbox without this modification it is not difficult to fit in situ providing you have the equipment.  This includes:

1. Ramps or a hoist to gain adequate access underneath.

2. Electric drill and drill bits.

3. Container for catching the oil.

4. Tap for threading a suitable hole.

5. Suitable shortened bolt (perhaps M8 size) and washer.

6. Squeezy bottle and a suitable length (about 0.5M) of plastic piping for refilling.


With the car raised, drill a pilot hole (2mm drill will do as its into aluminium) in the position shown. You can happily drill through the case to about 2.5cm depth without fear of hitting any of the gears. The casing is probably about 1cm thick in this area and has an internal flange behind so I am told. Allow the oil to drain. This could take an hour or so with the small pilot hole.  You could of course enlargen it at this stage but the drill will spray oil when turning. One point to consider is the swarf. Drill at low speed and remove frequently to wipe the swarf off.

Once the oil has drained enlargen the hole to a suitable size for an appropriate tap. Tap the hole. Proceed with care and remove frequently to remove the swarf. Smooth off the casting lip if it is likely to foul the bolt head. Fit the bolt and washer (shorten if necessary to about 1.5cm thread depth, although I don't think the length is critical). Do not overtighten as it's only an alloy casing.

Refill with SAE 75-90 semi synthetic oil. The filler hole is on the left side of the gearbox about 15cm forward of the new sump plug. Fill a squeezy bottle with the oil. Attach a plastic pipe, locating the other end in the hole. Squeeze the oil in uphill until oil drains out of the hole. The gearbox will take up to 1.9L oil maximum.


Job done.