ok im baffaled here i have a 2006 5.4 that hops or shakes or what have you not sure the best way to describe it but it only does it on slow hard turns ( out of a parking spot on to a road ext.) it does it thu the turn and stops occationaly it does it on a slow straght start. now heres the kicker i know 3 other people who have had the same issue at about 85k (i have 87k) 2 of them got rid of the truck before finding the prob and the other one it just whent away. i dont know where to start or if this is even the right forum for this only thing i do know is it is not the trans just had a new one put in and it did it before and continues here after. i thank you for any help at all i apologiz for the wordy description figure more info better then less

 

ok so after some more serchin (dont normal have time for that) i found somthin close to this could a fluid change be all it needs comment if you like sorry for not serchin beter thanks guys

 

Sounds like a problem I had. Do you have a limited slip diff? If so, just change the oil and don't forget the friction modifier.

 

The slipping or skipping that you are feeling are the differential clutches in the Rear differential, Most likely if you do a differential service and put in a bottle of ford friction modifier that it will go away for awhile..... Eventually you will need to replace the differential clutches though..... The service is a band-aid for now...... The clutches are not bad to do... you either have a 8.8 or 9.75 rear in it and either one arent that bad.
When you go to order them you will need the axle tag so take it off and take it with you, They will want to know ratio etc. etc. Most likely 3.55 if I had to guess ( most common ) Also, you can make sure that it is a limited slip by looking at the axle tag... If it is it will have 3L55, if it is not it will have 3 55 no L in between.... The L stands for limited ! Have fun, Bob

 

Also on the door tag on the axle code, if there is a letter like h-9 it,s a l/s.