Recently, I've noticed a sort of grinding/scrubbing sound from the rear of my 1990 911 C4. The noise has become increasingly noiser and is more pronounced at low speeds when I apply the brakes. Is this indicative of the bearings needing to be lubricated or something else?

C. Wilson

 

The rear wheel bearings are sealed and can not be greased, they must be replaced. Could also be brake pads worn down to virtually nothing, or CV joints going bad. Noises, unfortunately, are almost impossible to diagnose over the internet.