Gearbox/OD Oil Change

The hollow drain plug from the roadster and some metal debris. As I recall the V8 drain plug was flat:

Roadster sump and gasket/filter, no damage to this on removal unlike the V8:

Sump and all the relief valve and filter components from the roadster. The V8 didn't have the coarse screen shown here, may have been left inside. Note all the shims go between the valve plunger and the spring, increasing overall thickness sharpens/speeds-up engagement, reducing overall thickness softens/slows engagement:

Yet another variation, a cylinder with cut-outs at one end, in place of my roadster coarse screen. Note that John Twist shows this type with the cut-out facing the hex plug, and not as here. It could make a difference if the oil has to flow back up the tube to escape from the slots rather than exiting directly, and is maybe why it was changed to the coarse screen I found which can be fitted either way up: Photo: Corky

This is a composite using the Parts Catalogue drawing and descriptions from the Workshop Manual, however the 'low-pressure valve plug', 'valve spring' and 'valve ball' at the upper left are only shown in the Parts Catalogue and Haynes but not the Workshop Manuals, and I didn't find them in either of my cars. Possibly stuck up inside which is why it is essential to keep a clean container under the OD at all times in case bits drop out. The coarse screen I found is only shown in the late Workshop Manuals such as for 1977 and 78:

Plastic squeezy bottle for gear and diff oil, with a flexible spout that just fits in the length of tubing, and the tubing just fits in the filler hole on both side and top fill gearboxes. The snug fit between spout and tubing means that even though the 'join' is horizontal when filling in the footwell no oil leaks out from it. But put plenty of cloths and paper down over your carpets just in case, I still spilt a little. This tubing is probably longer than it needs to be even for the side-fill gearbox:

Location of the access hole and bung AHH6507:

Loop of cord on the dipstick to aid removal:

The bung isn't pushed all the way in, just until the body panel slots into the groove (arrowed):

Note that the bung is still present on rubber bumper cars with the side-fill gearbox, pre-77 at least, so those gearboxes can also be filled from the cabin. The Parts Catalogue for 77 on also includes it, suppliers give various info - '62-67' or 'CB' which is obviously incorrect, Moss says '62-80'. For it not to be needed on later cars the tunnel would need to have been altered, which seems unlikely. Some have said the 77 and later console doesn't give access to it (if there), but looking at consoles the fixing holes look to be the same distance from the rear edge on both types, which would mean the panel they screw into would have to be further back, which also seems unlikely.