Re: 2000 F150 shudders (rear end?)
You can start with just adding a bottle of modifier to see if that stops it. It's that or change the fluid to the proper weight of Royal Purple lube. I even found by replacing the rear shocks it helped stop it from chattering going around corners. I replaced the stock LS carrier with a TruTrac when I changed rear gears. Made a world of difference.
02 F-150 FX4 w/Baer rotors,carbon kevlar pads,SS lines,remote coolers/filters. IAS shocks,LiveWire tuned by me.