Talking of differentials...

[Deadfast]

...the one in my V8S is making a horrible whining noise. I did finally manage to get the (stripped) filler plug out, and replaced the sludge with fresh, but it hasn't made much difference. Is this rebuild or replace time? If there is a better alternative? I'm generally keen to upgrade where possible. Escort Cosworth is where it came from I think.

Cheers.