HP Autowerks supplied the Output shaft seal with my Wavetrac diff. That's a good thing because it was pretty tough to get them out
I saw no need to replace anything else.
'08 E90 335i 6MT. Under construction for a 'few good mods'
'09 E93 M3 6MT, H&R sports, Spec TwinDisc P-trim, UCP, FOR SALE
'09 Z4 sDrive35i DCT, MHD Backend flash, JB4, DCI