A sump-plug or drain-plug wrench or key usually has a range of probably 5-10 head sizes for undoing and tightening various sizes of sump, rear axle, or gearbox drain plugs. Some wrenches have spanner-type heads for fitting over projecting plugs; others have key-type heads for fitting into recessed drain-plugs. Combination wrenches have a mixture of both types.

Guides that use

Checking the gearbox oil level, draining and refilling

Layout under a transverse-engined front-wheel-drive car The filler plug is on the side of the ge...

Changing an oil filter

Fit the sealing ring in the mounting flange. Replace the spring over the central bolt, followed ...