im sorry iwas not specific, i was refering to VLSD, Viscous limited Slip. like in the 91 B13 SE-R or G50 series Q45s. is it a sealed up unit like a Clucth type diff. ? What raises this question at work we have an new BG Differential Flush/drain and fill machine. For a vehicle with a LSD use must use the LSD addative which is safe for Clutch types at least, i was trying to figure out if were also safe for a "VLSD" as well. :dumbass: thanksStevenLK said:im sure he's probably talking about Vlsd