Jason8691

Ive changed mine every 20k, the last time the fluid was still clean and there was hardly any metal on the magnet.

BradOKeefe

I recently purchased a 2009 F150 STX, and just received an email from the dealer that my 3000 mile service is due and the manufacture recommends:

Your 2009 Ford Pickup is due for its 3,000-Mile Service.
VIN: xxxxxxxxxxxxxxxxxxxx
Services recommended by your manufacturer and Mac Haik Ford include:
REPLACE REAR AXLE FLUID
*Please disregard any recommended services that have been recently performed.
Manufacturer-recommended service data provided by Mitchell1 based on vehicle make, model and year.

This seems really odd.

Brad

dba12345

My brothers 2003 F150 also has this play in the rear axle. On his truck you can shake the back and make it clunk. There is a noticable in-and-out movement when you jack up the rear end. He just bought the truck last year, the rear end has had some work he does not know what.

Have you been able to figure out what is wrong. Are the axle retainer clips worn.

resq302

The one dealership I brought it to said it was normal play and that play has to be in the rear axle. No freakin duh! I had another run in with a separate dealership when my truck started knocking. Turns out the cam phasers and adjusters were bad on the pass. side. After all was said and done and having my truck for a whole 4 days, I got it back with the noise a lot quieter but there was still a tapping noise there. Complained to Ford customer service about it and they sided with the dealership. Went back to the dealership and requested to talk to the service manager who said that the 5.4l 3 valve engines will sound like a diesel and there was a bulletin on it. When I asked him for a copy of it so when I traded my truck in, the salesman could not give me **** about the tapping noise, he refused and said it was "sensitive Ford documentation" and "could not be given out to the public". What a load of crap! No wonder why the call them Stealerships!

Kattumaram

As I recall the owner's manual for my '97 XLT calls for a change in differential lube at 100K. Extreme service would likely reduce that figure quite a bit. The ID tag attached to a diff cover bolt specifies 75W140 full synthetic lube only....a good idea no matter what the tag says.

goracer

I change mine very year but I do drive through lakes and play in the mud. I just finished another one over the weekend, as I had to replace a seal. Wow, what a PIA those seals are! Anyhow, i've never had a clunk sound with the truck. I did with my CRX, and had to replcae the half shaft of the axle. Check if you have an axle seal leak. Maybe your bearings wore out and the axle is bad. It sounds like you need to try several dealerships to find one that is ok with doing warranty work.

Kattumaram

The axle is retained in the differential by a U-washer, or C-clip. A certain amount of in-out slack is normal and may cause a clunk. If the in-out slack seems excessive, then the C-clip and/or the slot in the end of the axle where the C-clip fits could be worn. Wear at the end of the axle or the contact patch the axle makes on the differential pinion gear shaft can also cause excessive slack. The only way to tell is to pull the diff cover, pinion gear shaft and C-clips and look for obvious points of wear. The pinion gear shaft is retained with a threaded lock pin, about 8mm.
C-clip axles suck.

FX4_GUY

According to the Haynes Manual I just bought it says to check it every 6 months and to change the diff oil out every 30,000 miles or 2 years which ever comes first