We have 3 6.0's and they all have the same cold start and hard shift when cold. when it warms up, it runs like a champ. they also have a little noise in the front end when you hit a bump.
Any easy or cheap fixes. Ford dealerships around here could not put a belt on a lawn mower!

 

Try synthetic 5-40 and check the sway bar bushings.

 

Will seafoam cure it?

 

if it's a sticky injectors it will help.run at least 2 cans in oil and run diesel klean double the amount in the tank.Run it hard for a good hour,then you will have to change the oil.Most likely the oil will be very dirty full of soot.If this does not help,most likely one or more injectors will need replace.Hope this helps ALSO if it does help run 5-40 syc to help with other sticky's

 

they smoke like hell when they are cranked!