Abstract: An external lubricant reservoir of the type that is replenished by injection is provided in the form of a flexible membrane sealed to a lubricant distributor. The lubricant distributor consists of a membrane-mounting disk and a lubricant feed tube. The feed tube communicates with the reservoir interior through a passage in the disk. The feed tube is designed to be inserted into a lubricant passage in the housing of a joint or a bearing. A preferred embodiment of the reservoir enables the membrane to be wedged between a joint or bearing housing and the underside of the membrane-mounting disk to effect a sealed connection between the two.