I have a nice clunking sound coming from my front diff. It only happens when I'm rolling backwards and I start to go forward. So I have had two people tell me the same thing. The backlash may be off. What do you think? Also, would this cause my front pinion seal to leak constantly?

 

Park in 2 WD , crawl under and grab the front driveshaft near the pinion and try to move it up and down , checking for a loose pinion nut or bearing.Then start the truck , put it in 4 WD and move it forward and back a few feet.Shut it off in gear .Crawl back under and twist the driveshaft back and forth to see how much play/backlash it has .There should be some but not excessive.

 

Well I don't know how much play is excessive so I will post a video of it.

 

ford probably ****ed it up when they replaced your front pinion seal. probably did not torque the pinion nut down enough.

 

I doubt there is a way to prove that they messed it up. The only thing I have now is that they worked on it last. I'm about ready to trade the damn truck in anyway.

 

check the u-joints in the front shaft as well. that will clunk if there bad

 

I know that but its for sure coming from the front diff. I can see and feel that it is.