OK so I noticed the last few weeks that I have just a small shutter coming from my rear end every now and then. It feels like it locks up for just a sec and then is fine. It will normally do this earlier in the day and maybe once or twice. Is this telling me its time to add some more friction modifier into the rear diff or do I have another issue. I don't notice it once the truck is warmed up and been driving around some.



2006 F150 Screw Fx4

 

I feel the same rear end shudder you feel every now and then.

 

Sounds like its time for the modifier Drew.

 

Yeah that's what I was thinking too. I guess i will change out all teh fluid even though i know its not needed just to be on the safe side.

 

There is also a possibility the parking brake shoes (inside the rear disc/drums) are dragging intermittantly...