I would go for that, check the associated gearbox / clutch parts for wear etc then change the box oil, easily done if youve never done it before.
I use Millers Oils for all my oils, engine, gearbox and diff, although diff is yet to be done lol, looks like the previous owner liked nuts on their car to be extremely tight :roll: looks like the tommy bars coming out lol :twisted:
Ant.