B44 diff noise on braking?

[Andy-j.smith6]

Hi guys

My rear diff (I think) is making some noise when I brake. Hard to explain the noise, not high pitched, more of a pulse.

Guess it means I need to do some maintenance. Is it just a rebuild, what will I need to replace. Seen the diff rebuild kits for sale, is that what I should do. Or is it likely that there is something else wrong causing the noise.

Cheers
Andy