This spring I installed a Ford OEM limited slip unit in my 05 F 150. Recently I notice a brief, intermittent shudder when turning right or left from a stop sign. Does not do it all the time. I don't notice this any other time. The Valvoline synthetic oil I used said the Ford additive was not needed. Is this the "nature of the beast", should I be concerned, should I put the additive in anyway?

 

you need the friction modifier. Go to Auto Zone and get a 7 oz tube for $8. and pour it into the unit.