i have a 2004 stx RCSB 4x4 with 94000 miles. i noticed that while driving at hwy speeds when i let off the gas there be a clunk i can feel. sounds like from the rear of the truck. it also happens when i give it gas again after letting off. and about 50% of the time it will also make a clunk when shifting from drive to reverse or from park to reverse. anyone have any ideas what this could be? i went to ford and they gave me some blue grease for the slip yoke and i used it and it didnt seem to change anything. Thanks

 

Check your U-joints.

 

i had a problem like this with my 04 explorer, but im sure trucks are different. but it was the solenoid in the tranny. everytime i go from park to reverse or park to drive it was sloppy. kinda like a clunk, the suv would jerk into gear.

 

05 F150 FX4 78K miles.

Mine did it new, maybe 2,000 miles.
Dealership took a peek and lubed it, went away until.

Now (78K miles), Dealership took a look, lubed it and said there were some metal shavings but not that bad. They said I'd probably need a new Drive Shaft in a couple years. They said there wouldn't be a catastrophic failure but just more consistent clunking down the road.

I'm kinda pissed, this should not have happened at 2K miles or
78k miles. I would think that major part should last much
longer than that.