i have a 06 lincoln mark lt 4x4 and sometimes in morning it seems it pulsates few times then goes away and abs light is on. last wk i did notice my pass rear break smelled real bad like caliper was frozen did it for day then went away not sure if its working or if it evan has anything to do with pulsating and abs light on maybe caliper/rotor got real hot and messed up something on abs. another problem not sure if its related when i take corners *** end feels like some things grabbing thought it was inside rearend thought it was chatter from maybe having old fluid so i changed fluid still there not sure if its cause i need more friction stuff only put 4oz or maybe rear end is going or maybe its cause of caliper

 

If it feels like it is grabbing and you smelled a burnt smell there needs to be a tear down and inspection. You may have a seized caliper piston on one side and if so, your rotor is possibly grooved from offset wear along with the brake pad. New piston rebuild kit or new refurbished calipers are in order in this case.

If you did not see any metal shavings in the rear end fluid everything should be in tact and functional. Maybe try finding some mud and drive through it slowly to see that the LSD is operating. 4oz of modifier is all you need for a stock diff cover/fluid capacity.