'04 Scab, FX4, 3.73LS, 23K miles

My truck recently starting making a thumping noise when turning, specifically when I change directions quickly. Like when I pull into the school lot, I turn in off the street making a sharp left, then I turn sharp right to go down the aisle.

The thump sounds like when you have something in the bed that slides around and thumps the bed walls.

I just had the truck in for replacement of a rear axle seal and wondering if maybe the mechanic could've left something loose.

Any suggestions other than taking it in on Monday?

 

Slip clunk....usually happens when making turns, and accelerating....thats when I first noticed mine. All I can say is continue to monitor it, and have the dealer look into it. Helps if you can continually duplicate it, and then do it for them. My biggest problem initially was them saying they couldn't duplicate it, when I did it for them it helped, but not enough for them to ever fix it, so I lemoned it. (that was an '05 FX4 SCAB, 3.73)

I guess just read up a little on these clunk posts.

 

I corrected my diff clunk with Amsoil fully synthetic fluid. It is flawless now and extremely smooth but I dont think anyone believes me, thats cool though they can thump and clunk while I cruise in smoothness

 

Seems like quite a coincidence.

I drive 22K miles w/o a single sound
I take it in for a rear axle seal replacement
They fix my seal and top off the diff fluid
and voila.....diff clunk?

I'll take it in and have them check it out. Thanks all.

 

you didnt mention that although, If you are looking to ford to know anything about lubrication dont hold your breath, the diff fluid they use isnt suitable for a limited slip diff

 

hey did yours clunk on take off? mine does and the dealer put some grease on it,but it didn't help.

 

No clunking or slipping, only a thump when changing directions quickly. Happens if on or off the throttle. Feels like what a loose wheel bearing would feel like if we had those in back. Will get it back to the dealership next week sometime.

 

sounds like maybe you have a different prob.

 

I've had the same loud noise and thought it was some lumber moving in the bed of the truck. Is there a specific rear end differential that this effects and are there any TSB's?

 

Mine did that. I could duplicate the sound when driving slow through a parking lot by turning the steering wheel back and forth. It turned out to be the leaf springs. They greased them and it went away for a little while. They ended up replacing the springs. This happened around 20,000 miles.