W126 LSD rebuild

Has anyone done one of these?

I assume the clutch packs in the LSD need replacing at some stage? I have changed the fluid but when doing some wheel spin recently it only laid a one wheel mark, the left wheel did not spin at all.

I would expect with a good LSD that a 560SEL Euro motor with no cats and a fresh head rebuild and chain replacement should easily lay two black lines.

I have searched here and also checked my MB Service CD Rom and nothing.

Cheers
Matt.